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Title:
ROTARY DRIVE
Document Type and Number:
WIPO Patent Application WO/2017/177335
Kind Code:
A1
Abstract:
A rotary drive includes a housing; a shaft rotatably mounted within the housing and rotatable about a drive axis; a passage internal the housing and extending circumferentially about the shaft; a stator vane within the passage; and a rotor vane within the passage. The stator and rotor vanes are movable between respective closed positions in which the stator and rotor vanes separate the passage into a circumferentially expanding chamber in fluid communication with an inlet in the housing and a circumferentially collapsing chamber in fluid communication with an outlet in the housing, and respective open positions in which the rotor vane is movable circumferentially past the stator vane during rotation of the shaft.

Inventors:
MURPHY, Braden (130 Cornwallis Drive, Calgary, Alberta T2K 1V1, T2K 1V1, CA)
Application Number:
CA2017/050460
Publication Date:
October 19, 2017
Filing Date:
April 13, 2017
Export Citation:
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Assignee:
MONASHEE PUMPS INC. (103-41 Chelton Woods Lane, Halifax, Nova Scotia B3M 3Z8, B3M 3Z8, CA)
International Classes:
F01C1/44; E21B4/02; F04C2/344; F04C13/00
Domestic Patent References:
WO2014121872A22014-08-14
Foreign References:
US20150114721A12015-04-30
CN1025967C1994-09-21
DE4427105C11996-01-04
Attorney, Agent or Firm:
BERESKIN & PARR LLP/S.E.N.C.R.L., S.R.L. (40 King Street West, 40th FloorToronto, Ontario M5H 3Y2, M5H 3Y2, CA)
Download PDF:
Claims:
CLAIMS

1 . A rotary drive comprising: a) a housing having a cylindrical casing extending along a drive axis between axially spaced apart first and second end caps; b) a shaft rotatably mounted within the housing and rotatable relative to the casing about the drive axis; c) an annular passage radially intermediate the shaft and the casing and bounded axially by the end caps; d) at least one stator vane extending axially across the passage, the at least one stator vane pivotable about a stator vane axis fixed relative to the casing between a stator vane closed position for inhibiting circumferential fluid flow in the passage across the stator vane, and a stator vane open position; e) at least one rotor vane extending axially across the passage, the at least one rotor vane pivotable about a rotor vane axis fixed relative to the shaft between a rotor vane closed position for inhibiting circumferential fluid flow in the passage across the rotor vane, and a rotor vane open position, f) wherein when in the closed positions, the stator and rotor vanes separate the passage into at least one circumferentially expanding chamber and at least one circumferentially collapsing chamber spaced circumferentially apart from the at least one expanding chamber, the at least one expanding chamber in fluid communication with at least one inlet in the housing for receiving fluid in the at least one expanding chamber, and the at least one collapsing chamber in fluid communication with at least one outlet in the housing for evacuating fluid from the at least one collapsing chamber, and g) wherein when the rotor and stator vanes are in the open positions, the at least one rotor vane is movable circumferentially past the at least one stator vane during rotation of the shaft.

2. The rotary drive of claim 1 , further comprising a vane pivoting mechanism for pivoting at least one of the at least one stator vane and the at least one rotor vane in at least one direction between the open and closed positions when the shaft rotates through at least one predetermined angular position.

3. The rotary drive of any one of claims 1 to 2, wherein the rotor vane axis and the stator vane axis pass through the passage parallel to the drive axis. 4. The rotary drive of any one of claims 1 to 3, wherein the at least one rotor vane has a rotor vane height bounded by a rotor vane root edge and an opposed rotor vane tip edge, the rotor vane root edge proximate the shaft and the rotor vane tip edge proximate the casing when the at least one rotor vane is in the rotor vane closed position, and wherein the rotor vane axis is intermediate the rotor vane tip edge and the rotor vane root edge.

5. The rotary drive of claim 4, wherein when the at least one rotor vane is in the rotor vane closed position, the rotor vane tip edge is spaced radially apart from the casing by a rotor vane clearance gap for permitting interference free movement of the rotor vane tip edge relative to the casing. 6. The rotary drive of any one of claims 1 to 5, wherein when the at least one rotor vane is in the rotor vane open position, the at least one rotor vane is spaced radially apart from the shaft by a rotor vane flow gap for permitting circumferential fluid flow in the passage across the at least one rotor vane.

7. The rotary drive of any one of claims 1 to 6, wherein the at least one stator vane has a stator vane height bounded by a stator vane root edge and an opposed stator vane tip edge, the stator vane root edge proximate the casing and the stator vane tip edge proximate the shaft when the at least one stator vane is in the stator vane closed position, and wherein the stator vane axis is intermediate the stator vane tip edge and the stator vane root edge. 8. The rotary drive of claim 7, wherein when the at least one stator vane is in the stator vane closed position, the stator vane tip edge is spaced radially apart from the shaft by a stator vane clearance gap for permitting interference free rotation of the shaft relative to the stator vane tip edge.

9. The rotary drive of any one of claims 1 to 8, where when the at least one stator vane is in the stator vane open position, the at least one stator vane is spaced radially apart from the casing by a stator vane flow gap for permitting circumferential fluid flow in the passage across the at least one stator vane. 10. The rotary drive of any one of claims 1 to 9, wherein the first end cap includes a first stator disc fixed relative to the casing and the second end cap includes a second stator disc fixed relative to the casing, and wherein the at least one stator vane extends axially between a first end pivotally supported by the first stator disc and a second end pivotally supported by the second stator disc. 1 1 . The rotary drive of claim 10, wherein the at least one stator vane includes a stator vane first pin projecting axially from a first axial endface of the at least one stator vane, and a stator vane second pin projecting axially from an opposed second axial endface of the at least one stator vane, and wherein each of the stator vane first pin and the stator vane second pin is received in a respective aperture in the first stator disc and the second stator disc, respectively, for pivotally supporting the at least one stator vane.

12. The rotary drive of any one of claims 1 to 1 1 , wherein the first end cap includes a first rotor disc fixed to rotate with the shaft and the second end cap includes a second rotor disc fixed to rotate with the shaft, and wherein the at least one rotor vane extends axially between a first end pivotally supported by the first rotor disc and a second end pivotally supported by the second rotor disc.

13. The rotary drive of claim 12, wherein the at least one rotor vane includes a rotor vane first pin projecting axially from a first axial endface of the at least one rotor vane and a rotor vane second pin projecting axially from an opposed second axial endface of the at least one rotor vane, and wherein each of the rotor vane first pin and the rotor vane second pin is received in a respective aperture in the first rotor disc and the second rotor disc, respectively, for pivotally supporting the at least one rotor vane.

14. The rotary drive of any one of claims 1 to 13, wherein the at least one inlet extends axially through the first end cap.

15. The rotary drive of any one of claims 1 to 14, wherein the at least one outlet extends axially through the second end cap.

16. The rotary drive of any one of claims 1 to 13, wherein at least one of the at least one outlet and the at least one inlet extends radially through the casing. 17. The rotary drive of any one of claims 1 to 16, wherein the at least one rotor vane comprises at least two rotor vanes each pivotable about a respective rotor vane axis, and the at least one stator vane comprises at least two stator vanes each pivotable about a respective stator vane axis.

18. A rotary motor comprising: a) a housing having a cylindrical casing extending along a drive axis between axially spaced apart first and second end caps; b) a shaft rotatably mounted within the housing and rotatable relative to the casing about the drive axis; c) an annular passage radially intermediate the shaft and the casing and bounded axially by the end caps; d) at least one stator vane extending axially across the passage, the at least one stator vane pivotable about a stator vane axis fixed relative to the casing between a stator vane closed position for inhibiting circumferential fluid flow in the passage across the stator vane, and a stator vane open position; e) at least one rotor vane extending axially across the passage, the at least one rotor vane pivotable about a rotor vane axis fixed relative to the shaft between a rotor vane closed position for inhibiting circumferential fluid flow in the passage across the rotor vane, and a rotor vane open position, f) wherein when in the closed positions, the stator and rotor vanes separate the passage into at least one circumferentially expanding chamber and at least one circumferentially collapsing chamber spaced circumferentially apart from the at least one expanding chamber, the at least one expanding chamber in fluid communication with at least one inlet in the housing for receiving pressurized fluid for bearing against a trailing face of the at least one rotor vane to urge rotation of the shaft in a power direction, and the at least one collapsing chamber in fluid communication with at least one outlet in the housing for evacuating fluid from the at least one collapsing chamber, and g) wherein when the rotor and stator vanes are in the open positions, the at least one rotor vane is movable circumferentially past the at least one stator vane during rotation of the shaft in the power direction.

19. A rotary pump comprising: a) a housing having a cylindrical casing extending along a drive axis between axially spaced apart first and second end caps; b) a shaft rotatably mounted within the housing and rotatable relative to the casing about the drive axis; c) an annular passage radially intermediate the shaft and the casing and bounded axially by the end caps; d) at least one stator vane extending axially across the passage, the at least one stator vane pivotable about a stator vane axis fixed relative to the casing between a stator vane closed position for inhibiting circumferential fluid flow in the passage across the stator vane, and a stator vane open position; e) at least one rotor vane extending axially across the passage, the at least one rotor vane pivotable about a rotor vane axis fixed relative to the shaft between a rotor vane closed position for inhibiting circumferential fluid flow in the passage across the rotor vane, and a rotor vane open position; f) wherein when in the closed positions, the stator and rotor vanes separate the passage into at least one circumferentially expanding chamber and at least one circumferentially collapsing chamber spaced circumferentially apart from the at least one expanding chamber, the at least one expanding chamber in fluid communication with at least one inlet in the housing for drawing fluid into the at least one expanding chamber during rotation of the shaft in a power direction, and the at least one collapsing chamber in fluid communication with at least one outlet in the housing for discharging pressurized fluid from the at least one collapsing chamber during rotation of the shaft in the power direction, and g) wherein when the rotor and stator vanes are in the open positions, the at least one rotor vane is movable circumferentially past the at least one stator vane during rotation of the shaft in the power direction.

20. The pump of claim 19, further comprising a vane pivoting mechanism for pivoting the at least one stator vane and the at least one rotor vane from respective closed positions to respective open positions when the shaft rotates through at least one predetermined angular position. 21 . The pump of claim 20, wherein the vane pivoting mechanism urges at least one of the at least one stator vane and the at least one rotor vane to pivot from respective open positions back to respective closed positions when the at least one rotor vane passes the at least one stator vane.

22. A rotary drive comprising: a) a housing; b) a shaft rotatably mounted within the housing and rotatable about a drive axis; c) a fluid passage internal the housing and extending circumferentially about the shaft; d) at least one stator vane within the passage, the at least one stator vane movable between a stator vane open position and a stator vane closed position, and when in the stator vane closed position, the at least one stator vane presents a stator vane high-pressure face extending radially across the passage and a circumferentially opposite stator vane low-pressure face extending radially across the passage, and e) at least one rotor vane within the passage and fixed to rotate with the shaft relative to the at least one stator vane, the at least one rotor vane movable between a rotor vane open position and a rotor vane closed position, and when in the rotor vane closed position, the at least one rotor vane presents a rotor vane high- pressure face extending radially across the passage and a circumferentially opposite rotor vane low-pressure face extending radially across the passage; f) wherein when in respective closed positions, the rotor and stator vanes separate the passage into at least one high pressure chamber bounded circumferentially by the stator vane and rotor vane high-pressure faces, and at least one low pressure chamber bounded circumferentially by the stator vane and rotor vane low- pressure faces, the at least one high pressure chamber in fluid communication with at least one first flow port in the housing, the first flow port being one of an inlet and an outlet, and the at least one low pressure chamber in fluid communication with at least one second flow port in the housing, the second flow port being the other one of the inlet and the outlet; and g) wherein when in respective open positions, the stator vane and the rotor vane are retracted relative to one another for permitting the rotor vane to move circumferentially past the stator vane during rotation of the shaft. 23. A rotary drive comprising: a) a housing; b) a shaft rotatably mounted within the housing and rotatable about a drive axis; c) a passage internal the housing and extending circumferentially about the shaft; d) at least one stator closure member within the passage and movable between a stator closure member closed position, in which circumferential fluid flow in the passage across the stator closure member in a circumferential first direction is blocked, and a stator closure member open position; e) at least one rotor closure member within the passage and fixed to rotate with the shaft relative to the stator closure member, the at least one rotor closure member movable between a rotor closure member closed position, in which circumferential fluid flow in the passage across the at least one rotor closure member in a second circumferential direction opposite the first direction is blocked, and a rotor closure member open position; f) wherein when in respective closed positions, the stator and rotor closure members separate the passage into at least one circumferentially expanding chamber in fluid communication with at least one fluid inlet in the housing for conducting fluid into the at least one expanding chamber during rotation of the shaft in a power direction, and at least one circumferentially collapsing chamber in fluid communication with at least one outlet in the housing for evacuating fluid from the at least one collapsing chamber during rotation of the shaft in a power direction; and g) wherein when in respective open positions, the at least one rotor closure member is movable circumferentially past the at least one stator closure member during rotation of the shaft in the power direction.

Description:
Rotary Drive

FIELD [0001 ] The disclosure relates to rotary drives, and more specifically, to rotary motors and rotary pumps.

BACKGROUND

[0002] U.S. Patent No. 3,966,369 (Garrison) discloses a positive displacement motor suitable for use in downhole drilling at the end of a drill string and driven by fluid, e.g., liquid mud, under high pressures. The motor has an arrangement of inlet and outlet ports in longitudinally extending circumferentially spaced rows for providing fluid at a substantially uniform pressure along substantially the length of the blades driving the motor so as to equalize the driving torque along the length of the rotor and avoid pressure differentials tending to twist the blade. A continuous ring isolates the adjacent rows of inlet and outlet ports.

[0003] U.S. Patent Application Publication No. 2015/006881 1 (Marchand et al.) discloses a downhole motor rotary drive system including a housing, a rotor rotatably and coaxially disposed within the housing, and an annular space between the rotor and housing. The rotor includes first and second ends, a bore extending between the first and second ends, an inlet port extending from the bore to the annular space, and an outlet port extending from the annular space to the bore. A plurality of gates are disposed within the annular space, each configured to engage the rotor and the housing, and a plurality of lobes extend within the annular space such that the lobes and the gates divide the annular space into a plurality of chambers. A flow path is defined by the annular space between the inlet and outlet ports, and the rotor is configured to rotate relative to the housing when a fluid is circulated along the flow path.

[0004] U.S. Patent No. 7,172,039 (Teale et al.) discloses a downhole tool for use in a wellbore. The downhole tool includes a housing having a shaped inner bore, a first end, and a second end. The downhole tool further includes a rotor having a plurality of extendable members, wherein the rotor is disposable in the shaped inner bore to form at least one chamber therebetween. Furthermore, the downhole tool includes a substantially axial fluid pathway through the chamber, wherein the fluid pathway includes at least one inlet proximate the first end and at least one outlet proximate the second end.

SUMMARY

[0005] According to some aspects, a rotary drive includes: a) a housing having a cylindrical casing extending along a drive axis between axially spaced apart first and second end caps; b) a shaft rotatably mounted within the housing and rotatable relative to the casing about the drive axis; c) an annular passage radially intermediate the shaft and the casing and bounded axially by the end caps; d) at least one stator vane extending axially across the passage, the at least one stator vane pivotable about a stator vane axis fixed relative to the casing between a stator vane closed position for inhibiting circumferential fluid flow in the passage across the stator vane, and a stator vane open position; and e) at least one rotor vane extending axially across the passage, the at least one rotor vane pivotable about a rotor vane axis fixed relative to the shaft between a rotor vane closed position for inhibiting circumferential fluid flow in the passage across the rotor vane, and a rotor vane open position. When in the closed positions, the stator and rotor vanes separate the passage into at least one circumferentially expanding chamber and at least one circumferential ly collapsing chamber spaced circumferentially apart from the at least one expanding chamber, the at least one expanding chamber in fluid communication with at least one inlet in the housing for receiving fluid, and the at least one collapsing chamber in fluid communication with at least one outlet in the housing for evacuating fluid from the at least one collapsing chamber, and wherein when the rotor and stator vanes are in the open positions, the at least one rotor vane is movable circumferentially past the at least one stator vane during rotation of the shaft.

[0006] In some examples, the rotary drive includes a vane pivoting mechanism for pivoting at least one of the at least one stator vane and the at least one rotor vane in at least one direction between the open and closed positions when the shaft rotates through at least one predetermined angular position. In some examples, the vane pivoting mechanism urges the at least one stator vane toward the stator vane closed position when the shaft rotates through a stator vane first angular position. In some examples, the vane pivoting mechanism urges the at least one stator vane toward the stator vane open position when the shaft rotates through a stator vane second angular position. In some examples, the vane pivoting mechanism urges the at least one rotor vane toward the rotor vane closed position when the shaft rotates through a rotor vane first angular position. In some examples, the vane pivoting mechanism urges the at least one rotor vane toward the rotor vane open position when the shaft rotates through a rotor vane second angular position. In some examples, the rotor vane first position corresponds to the stator vane first position. In some examples, the rotor vane second position corresponds to the stator vane second position. In some examples the rotor vane first position and the stator vane first position correspond to a common first angular position of the shaft. In some examples, the rotor vane second position and the stator vane second position correspond to a common second angular position of the shaft.

[0007] In some examples, the rotor vane axis and the stator vane axis pass through the passage and extend parallel to the drive axis. The rotor vane axis and the stator vane axis may be radially offset from one another, with the rotor vane axis offset radially inwardly toward the shaft and the stator vane axis offset radially outwardly toward the casing. The rotor vane axis may rotate relative to the casing about the drive axis at a first radial distance from the drive axis, and the stator vane axis may rotate relative to the shaft about the drive axis at a second radial distance from the drive axis. The second radial distance may be greater than the first radial distance. [0008] In some examples, the at least one rotor vane has a rotor vane height bounded by a rotor vane root edge and an opposed rotor vane tip edge. The rotor vane root edge may be proximate the shaft and the rotor vane tip edge may be proximate the casing when the at least one rotor vane is in the rotor vane closed position. The rotor vane axis may be intermediate the rotor vane tip edge and the rotor vane root edge. [0009] In some examples, when the at least one rotor vane pivots from the rotor vane closed position toward the rotor vane open position, the rotor vane tip edge pivots about the rotor vane axis in a rotor vane first direction toward the shaft. When the at least one rotor vane pivots from the rotor vane open position toward the rotor vane closed position, the rotor vane tip edge may pivot about the rotor vane axis in a rotor vane second direction toward the casing. The rotor vane second direction may be opposite the rotor vane first direction. When the at least one rotor vane is in the rotor vane closed position, a rotor vane stop surface fixed to the rotor vane may abut a rotor abutment surface fixed relative to the shaft to inhibit further pivoting of the rotor vane in the rotor vane second direction.

[0010] In some examples, when the at least one rotor vane is in the rotor vane closed position, the rotor vane tip edge can be spaced radially apart from the casing by a rotor vane clearance gap for permitting interference free movement of the rotor vane tip edge relative to the casing. [001 1 ] In some examples, when the at least one rotor vane is in the rotor vane closed position, the rotor vane tip edge is in sliding contact with the casing.

[0012] In some examples, the at least one rotor vane has a rotor vane thickness bounded by a rotor vane trailing face and an opposed rotor vane leading face. The rotor vane trailing and leading faces may be bounded by the rotor vane root and tip edges. In some examples, when the at least one rotor vane is in the rotor vane closed position, the rotor vane trailing face extends radially across the passage and circumferentially bounds the at least one expanding chamber and the rotor vane leading face extends radially across the passage and circumferentially bounds the at least one collapsing chamber. [0013] In some examples, when the at least one rotor vane is in the rotor vane open position, the rotor vane trailing face is directed generally radially inwardly toward the shaft, and the rotor vane leading face is directed generally radially outwardly toward the casing and is spaced radially apart from the casing by a radially outer passage gap. The radially outer passage gap may be sized for accommodating circumferential movement of the at least one rotor vane past the at least one stator vane when the rotor and stator vanes are in respective open positions.

[0014] In some examples, when the at least one rotor vane is in the rotor vane open position, the rotor vane trailing face is disposed radially intermediate the rotor vane axis and an outer surface of the shaft, and is spaced radially apart from the shaft by a rotor vane flow gap. The rotor vane flow gap may permit circumferential fluid flow in the passage across the at least one rotor vane.

[0015] In some examples, the at least one stator vane has a stator vane height bounded by a stator vane root edge and an opposed stator vane tip edge. The stator vane root edge may be proximate the casing and the stator vane tip edge may be proximate the shaft when the at least one stator vane is in the stator vane closed position. The stator vane axis may be intermediate the stator vane tip edge and the stator vane root edge.

[0016] In some examples, when the at least one stator vane pivots from the stator vane closed position toward the stator vane open position, the stator vane tip edge pivots about the stator vane axis in a stator vane first direction toward the casing. When the at least one stator vane pivots from the stator vane open position toward the stator vane closed position, the stator vane tip edge may pivot about the stator vane axis in a stator vane second direction toward the shaft. The stator vane second direction may be opposite the stator vane first direction. When the stator vane is in the stator vane closed position, a stator vane stop surface fixed to the stator vane may abut a stator abutment surface fixed relative to the casing to inhibit further pivoting of the stator vane in the stator vane second direction.

[0017] In some examples, when the at least one stator vane is in the stator vane closed position, the stator vane tip edge can be spaced radially apart from the shaft by a stator vane clearance gap for permitting interference free rotation of the shaft relative to the stator vane tip edge.

[0018] In some examples, when the at least one stator vane is in the stator vane closed position, the stator vane tip edge is in sliding contact with the shaft. [0019] In some examples, the at least one stator vane has a stator vane thickness bounded by a stator vane trailing face and an opposed stator vane leading face. The stator vane trailing and leading faces may be bounded by the stator vane root and tip edges. In some examples, when the at least one stator vane is in the stator vane closed position, the stator vane leading face extends radially across the passage and circumferentially bounds the at least one expanding chamber and the stator vane trailing face extends radially across the passage and circumferentially bounds the at least one collapsing chamber.

[0020] In some examples, when the at least one stator vane is in the stator vane open position, the stator vane leading face is directed generally radially outwardly toward the casing, and the stator vane trailing face is directed generally radially inwardly toward the shaft and spaced radially apart from the shaft by a radially inner passage gap. The radially inner passage gap may be sized for accommodating circumferential movement of the at least one rotor vane past the at least one stator vane when the rotor and stator vanes are in respective open positions.

[0021 ] In some examples, when in respective open positions, the at least one rotor vane and the at least one stator vane are spaced radially apart by an intermediate clearance gap for permitting interference free movement of the at least one rotor vane past the at least one stator vane during rotation of the shaft. In some examples the intermediate clearance gap permits circumferential fluid flow past the at least one rotor vane and the at least one stator vane.

[0022] In some examples, when the at least one stator vane is in the stator vane open position, the stator vane leading face is disposed radially intermediate the stator vane axis and an inner surface of the casing, and is spaced radially apart from the casing by a stator vane flow gap. The stator vane flow gap may permit circumferential fluid flow in the passage across the at least one stator vane.

[0023] In some examples, the at least one inlet extends axially through the first end cap. In some examples, the at least one outlet extends axially through the second end cap. [0024] In some examples, at least one of the at least one inlet and the at least one outlet extends radially through the casing.

[0025] In some examples, the shaft includes an internal shaft conduit for conducting fluid, and at least one of the at least one inlet and the at least one outlet extends radially through the shaft for conducting fluid between the passage and the shaft conduit.

[0026] In some examples, the first end cap includes a first stator disc fixed relative to the casing, and the second end cap includes a second stator disc fixed relative to the casing. In some examples the first end cap includes a first rotor disc fixed to rotate with the shaft, and the second end cap includes a second rotor disc fixed to rotate with the shaft. In some examples, the first rotor disc is radially inward of the first stator disc and the second rotor disc is radially inward of the second stator disc. In some examples, the first stator disc axially overlaps the first rotor disc and the second stator disc axially overlaps the second rotor disc. [0027] In some examples, the at least one inlet extends axially through and is fixed relative to the first stator disc. In some examples, the at least one inlet extends axially through and is fixed relative to the first rotor disc. In some examples, the at least one outlet extends axially through and is fixed relative to the second stator disc. In some examples, the at least one outlet extends axially through and is fixed relative to the second rotor disc.

[0028] In some examples, the at least one rotor vane extends axially between a first end pivotally supported by the first rotor disc and a second end pivotally supported by the second rotor disc for pivoting about the rotor vane axis. In some examples, the at least one rotor vane includes a rotor vane first pin projecting axially from a first axial endface of the at least one rotor vane, and a rotor vane second pin projecting axially from an opposed second axial endface of the at least one rotor vane. Each of the rotor vane first and second pins may be received in a respective aperture in the first and second rotor discs for pivotally supporting the at least one rotor vane.

[0029] In some examples, the at least one stator vane extends axially between a first end pivotally supported by the first stator disc and a second end pivotally supported by the second stator disc for pivoting about the stator vane axis. In some examples, the at least one stator vane includes a stator vane first pin projecting axially from a first axial endface of the at least one stator vane, and a stator vane second pin projecting axially from an opposed second axial endface of the at least one stator vane. Each of the stator vane first and second pins may be received in a respective aperture in the first and second stator discs for pivotally supporting the at least one stator vane.

[0030] In some examples, the at least one rotor vane comprises a plurality of rotor vanes pivotable about respective rotor vane axes. The rotor vane axes may be spaced equally apart about the drive axis. The at least one stator vane may comprise a plurality of stator vanes pivotable about respective stator vane axes. The stator vane axes may be spaced equally apart about the drive axis.

[0031 ] In some examples, the plurality of rotor vanes includes a number of rotor vanes and the plurality of stator vanes includes a number of stator vanes. In some examples, the number of stator vanes may be equal to the number of rotor vanes. The number of stator vanes may be two, and the number of rotor vanes may be two. In some examples, the number of stator vanes may be greater than the number of rotor vanes. The number of stator vanes may be one greater than the number of rotor vanes. The number of stator vanes may be three, and the number of rotor vanes may be two.

[0032] According to some aspects, a rotary motor includes: (a) a housing having a cylindrical casing extending along a drive axis between axially spaced apart first and second end caps; (b) a shaft rotatably mounted within the housing and rotatable relative to the casing about the drive axis; (c) an annular passage radially intermediate the shaft and the casing and bounded axially by the end caps; (d) at least one stator vane extending axially across the passage, the at least one stator vane pivotable about a stator vane axis fixed relative to the casing between a stator vane closed position for inhibiting circumferential fluid flow in the passage across the stator vane, and a stator vane open position; and (e) at least one rotor vane extending axially across the passage, the at least one rotor vane pivotable about a rotor vane axis fixed relative to the shaft between a rotor vane closed position for inhibiting circumferential fluid flow in the passage across the rotor vane, and a rotor vane open position. When in the closed positions, the stator and rotor vanes separate the passage into at least one circumferentially expanding chamber and at least one circumferential ly collapsing chamber spaced circumferentially apart from the at least one expanding chamber. The at least one expanding chamber is in fluid communication with at least one inlet in the housing for receiving pressurized fluid. The pressurized fluid can bear against a trailing face of the at least one rotor vane to urge rotation of the shaft in a power direction. The at least one collapsing chamber is in fluid communication with at least one outlet in the housing for evacuating fluid from the at least one collapsing chamber. When the rotor and stator vanes are in the open positions, the at least one rotor vane is movable circumferentially past the at least one stator vane during rotation of the shaft in the power direction.

[0033] According to some aspects of the teaching disclosed herein, a rotary pump includes: (a) a housing having a cylindrical casing extending along a drive axis between axially spaced apart first and second end caps; (b) a shaft rotatably mounted within the housing and rotatable relative to the casing about the drive axis; (c) an annular passage radially intermediate the shaft and the casing and bounded axially by the end caps; (d) at least one stator vane extending axially across the passage, the at least one stator vane pivotable about a stator vane axis fixed relative to the casing between a stator vane closed position for inhibiting circumferential fluid flow in the passage across the stator vane, and a stator vane open position; and (e) at least one rotor vane extending axially across the passage, the at least one rotor vane pivotable about a rotor vane axis fixed relative to the shaft between a rotor vane closed position for inhibiting circumferential fluid flow in the passage across the rotor vane, and a rotor vane open position. When in the closed positions, the stator and rotor vanes separate the passage into at least one circumferentially expanding chamber and at least one circumferentially collapsing chamber spaced circumferentially apart from the at least one expanding chamber. The at least one expanding chamber is in fluid communication with at least one inlet in the housing for drawing fluid into the at least one expanding chamber during rotation of the shaft in a power direction. The at least one collapsing chamber is in fluid communication with at least one outlet in the housing for discharging pressurized fluid from the at least one collapsing chamber during rotation of the shaft in the power direction. When the rotor and stator vanes are in the open positions, the at least one rotor vane is movable circumferentially past the at least one stator vane during rotation of the shaft in the power direction.

[0034] In some examples, the rotary pump includes a vane pivoting mechanism for pivoting the at least one stator vane and the at least one rotor vane from respective closed positions to respective open positions when the shaft rotates through at least one predetermined angular position. In some examples, the vane pivoting mechanism urges at least one of the at least one stator vane and the at least one rotor vane to pivot from respective open positions back to respective closed positions when the at least one rotor vane passes the at least one stator vane.

[0035] In some examples, the at least one inlet includes a one-way fluid check valve for permitting flow of fluid into the at least one expanding chamber through the at least one inlet and blocking flow of fluid out from the at least one expanding chamber through the at least one inlet. In some examples, the at least one outlet includes a one- way fluid check valve for permitting flow of fluid out from the at least one collapsing chamber through the at least one outlet and blocking flow of fluid into the at least one collapsing chamber through the at least one outlet.

[0036] According to some aspects, a rotary drive includes a housing; a shaft rotatably mounted within the housing and rotatable about a drive axis; a fluid passage internal the housing and extending circumferentially about the shaft; at least one stator vane within the passage, the at least one stator vane movable between a stator vane open position and a stator vane closed position, and when in the stator vane closed position, the at least one stator vane presents a stator vane high-pressure face extending radially across the passage and a circumferentially opposite stator vane low- pressure face extending radially across the passage; and at least one rotor vane within the passage and fixed to rotate with the shaft relative to the at least one stator vane, the at least one rotor vane movable between a rotor vane open position and a rotor vane closed position, and when in the rotor vane closed position, the at least one rotor vane presents a rotor vane high-pressure face extending radially across the passage and a circumferentially opposite rotor vane low-pressure face extending radially across the passage. When in respective closed positions, the rotor and stator vanes separate the passage into at least one high pressure chamber bounded circumferentially by the stator vane and rotor vane high-pressure faces, and at least one low pressure chamber bounded circumferentially by the stator vane and rotor vane low-pressure faces, the at least one high pressure chamber in fluid communication with at least one first flow port in the housing, the first flow port being one of an inlet and an outlet, and the at least one low pressure chamber in fluid communication with at least one second flow port in the housing, the second flow port being the other one of the inlet and the outlet. When in respective open positions, the stator vane and the rotor vane are retracted relative to one another for permitting the rotor vane to move circumferentially past the stator vane during rotation of the shaft.

[0037] In some examples, the rotary drive comprises a rotary motor for driving rotation of the shaft in a power direction. In some examples, the at least one high pressure chamber comprises at least one expanding chamber and the first flow port is the inlet, and the at least one low pressure chamber comprises at least one collapsing chamber and the second flow port is the outlet. The rotor vane high-pressure face can comprise a rotor vane trailing face of the at least one rotor vane. The rotor vane low- pressure face can comprise a rotor vane leading face of the at least one rotor vane. The stator vane high-pressure face can comprise a stator vane leading face of the at least one stator vane. The stator vane low-pressure face can comprise a stator vane trailing face of the at least one stator vane.

[0038] In some examples, the rotary drive comprises a rotary pump for discharging pressurized fluid. In some examples, the at least one high pressure chamber comprises at least one collapsing chamber and the first flow port is the outlet, and the at least one low pressure chamber comprises at least one expanding chamber and the second flow port is the inlet. The rotor vane high-pressure face can comprise a rotor vane leading face of the at least one rotor vane. The rotor vane low-pressure face can comprise a rotor vane trailing face of the at least one rotor vane. The stator vane high-pressure face can comprise a stator vane trailing face of the at least one stator vane. The stator vane low-pressure face can comprise a stator vane leading face of the at least one stator vane. [0039] According to some aspects, a rotary drive includes a housing; a shaft rotatably mounted within the housing and rotatable about a drive axis; a passage internal the housing and extending circumferentially about the shaft; and at least one stator closure member within the passage and movable between a stator closure member closed position, in which circumferential fluid flow in the passage across the stator closure member in a circumferential first direction is blocked, and a stator closure member open position. The rotary drive further includes at least one rotor closure member within the passage and fixed to rotate with the shaft relative to the stator closure member. The at least one rotor closure member is movable between a rotor closure member closed position, in which circumferential fluid flow in the passage across the at least one rotor closure member in a second circumferential direction opposite the first direction is blocked, and a rotor closure member open position. When in respective closed positions, the stator and rotor closure members separate the passage into at least one circumferentially expanding chamber in fluid communication with at least one fluid inlet in the housing for conducting fluid into the at least one expanding chamber during rotation of the shaft in a power direction, and at least one circumferentially collapsing chamber in fluid communication with at least one outlet in the housing for evacuating fluid from the at least one collapsing chamber during rotation of the shaft in a power direction. When in respective open positions, the at least one rotor closure member is movable circumferentially past the at least one stator closure member during rotation of the shaft in the power direction.

[0040] In some examples, the at least one stator closure member comprises at least one stator vane and the at least one rotor closure member comprises at least one rotor vane.

[0041 ] The following summary is intended to introduce the reader to various aspects of the applicant's teaching, but not to define any invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings included herewith are for illustrating various examples of articles, methods, and apparatuses of the present specification and are not intended to limit the scope of what is taught in any way. In the drawings:

[0043] Figure 1 is a perspective view of an example rotary motor taken from a downstream end of the motor with inner elements visible through outer elements depicted in outline; [0044] Figure 2 is an end view of the downstream end of the motor of Figure 1 ;

[0045] Figure 3 is an exploded view of portions of the motor of Figure 1 ;

[0046] Figure 4 is a cross-sectional view of the motor of Figure 1 taken along line 4-4 of Figure 2;

[0047] Figure 5 is a cross-sectional view of the motor of Figure 1 taken along line 5-5 of Figure 2;

[0048] Figure 6a is a partially schematic cross-sectional view of the motor of Figure 1 taken along line 6a-6a of Figure 4, with the motor shown in one condition;

[0049] Figure 6b is the same view of the motor of Figure 6a but showing the motor in another condition; [0050] Figure 7a is a perspective view of portions of the motor of Figure 1 taken from an upstream end of the motor;

[0051 ] Figure 7b is a perspective view of portions of the motor of Figure 1 taken from a downstream end of the motor;

[0052] Figures 8a, 8b, and 8c are views of the structure of Figure 6a with the shaft at three rotational positions (at approximately 0 degrees, 100 degrees, and 180 degrees, respectively); [0053] Figures 9a is a partially schematic cross-sectional view of the motor of Figure 5, taken along the lines 9a-9a, and with the shaft at a first rotational position corresponding to that of Figure 8a;

[0054] Figures 9b and 9c are views of the structure of Figure 9a with the shaft at second and third positions, respectively, corresponding to the rotational positions of Figures 8b and 8c;

[0055] Figure 10a is a partially schematic cross-sectional view of the motor of Figure 4 taken along line 10a-10a, with the motor shown in a condition corresponding to that of Figure 8a; [0056] Figure 10b is the schematic representation of Figure 10a with the motor shown in another condition corresponding to that of Figure 8b;

[0057] Figure 10c is the schematic representation of Figure 10a with the motor shown in another condition corresponding to that of Figure 8c;

[0058] Figure 1 1 is an end view of a portion of a motor similar to Figure 1 , showing an alternate rotor vane in one condition;

[0059] Figure 1 1 a is an enlarged portion of Figure 1 1 ;

[0060] Figure 12 is the same view of the motor of Figure 1 1 , showing the rotor vane in another condition;

[0061 ] Figure 12a is an enlarged portion of Figure 12; [0062] Figure 13 is an end view of a portion of a motor similar to that of Figure 1 , showing an alternate stator vane in one condition;

[0063] Figure 13a is an enlarged portion of Figure 13;

[0064] Figure 14 is the same view of the motor of Figure 13, showing the stator vane in another condition; [0065] Figure 14a is an enlarged portion of Figure 14;

[0066] Figure 15 is a perspective view of another rotary motor;

[0067] Figure 16 is an exploded view of the motor of Figure 15; [0068] Figure 17a is a partially schematic cross-sectional view of the motor of Figure 15, shown in one condition;

[0069] Figures 17b-17f are views of the same structure as Figure 17a, showing a sequence of rotation from a first position in Figure 17a, through second-sixth positions in Figures 17b-17f, respectively;

[0070] Figure 18a is a partially schematic cross-sectional view of the motor of Figure 15, shown in one condition;

[0071 ] Figures 18b-18f are views of the same structure as Figure 18a, showing a sequence of rotation from a first position in Figure 18a, through second-sixth positions in Figures 18b-18f, respectively;

[0072] Figure 19A is a perspective view of portions of another rotary motor taken from a downstream end of the motor;

[0073] Figure 19B is another perspective view of portions of the motor of Figure 19A taken from a downstream end of the motor; [0074] Figure 20 is an exploded view of portions of the motor of Figure 19A;

[0075] Figure 21 is a partially schematic cross-sectional view of the motor of Figure 19A taken along line 21 -21 of Figure 19A;

[0076] Figure 22 is a perspective view of portions of another rotor structure for use with a motor like that of Figure 19A; [0077] Figure 22A is a cross-sectional view of the portions of the rotor structure of Figure 22 taken along line 22A-22A of Figure 22;

[0078] Figure 22B is a cross-sectional view of the portions of the rotor structure of Figure 22 taken along line 22B-22B of Figure 22;

[0079] Figure 23A is a perspective view of portions of another stator structure for use with a motor like that of Figure 19A;

[0080] Figure 23B is another perspective view of the portions of the stator structure of Figure 23A; [0081 ] Figure 24 is a perspective view of another rotary motor taken from an upstream end of the motor;

[0082] Figure 25 is an exploded view of the motor of Figure 24;

[0083] Figure 26 is a cross-sectional view of the motor of Figure 24 taken along line 26-26 of Figure 24;

[0084] Figure 27 is a cross-sectional view of the motor of Figure 24 taken along line 27-27 of Figure 24;

[0085] Figure 28 is a perspective view of another rotary motor taken from an upstream end of the motor; [0086] Figure 29 is another perspective view of the motor of Figure 28 taken from the upstream end of the motor;

[0087] Figure 30 is a perspective view of a rotary pump taken from an upstream end of the pump;

[0088] Figure 31 is a side view of the pump of Figure 30; [0089] Figure 32 is an exploded view of portions of the pump of Figure 30;

[0090] Figure 33 is a cross-sectional view of the pump of Figure 30 taken along line 33-33 of Figure 31 ;

[0091 ] Figure 34 is a cross-sectional view of the pump of Figure 30 taken along line 34-34 of Figure 31 ; [0092] Figure 35 is a cross-sectional view of the pump of Figure 30 taken along line 35-35 of Figure 31 ;

[0093] Figure 36 is a cross-sectional view of the pump of Figure 30 taken along line 36-36 of Figure 31 ;

[0094] Figure 37 is a cross-sectional view of the pump of Figure 30 taken along line 37-37 of Figure 31 ; and

[0095] Figure 38 is a cross-sectional view of the pump of Figure 30 taken along line 38-38 of Figure 31. DETAILED DESCRIPTION

[0096] Various apparatuses or processes will be described below to provide an example of an embodiment of the claimed subject matter. No embodiment described below limits any claim and any claim may cover processes or apparatuses that differ from those described below. The claims are not limited to apparatuses or processes having all of the features of any one apparatus or process described below or to features common to multiple or all of the apparatuses described below. It is possible that an apparatus or process described below is not an embodiment of any exclusive right granted by issuance of this patent application. Any subject matter described below and for which an exclusive right is not granted by issuance of this patent application may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors or owners do not intend to abandon, disclaim, or dedicate to the public any such subject matter by its disclosure in this document. [0097] According to some aspects of the teaching disclosed herein, design improvements can advantageously be made to rotary drives having pivoting vanes that transfer power between the vanes and a fluid passing through the rotary drive. The rotary drive may be a motor or a pump.

[0098] Referring to Figure 1 , an example fluid-driven rotary motor 100 is illustrated. The motor 100 is configured to rotate a shaft 102 in a power direction 104. The rotary motor 100 includes a housing 106 having a cylindrical casing 108 (shown transparent in Figure 1 ) extending along a housing axis 1 10 (also referred to as drive axis 1 10) between axially spaced apart first and second end caps 1 12, 1 14 (also referred to as upstream and downstream end caps 1 12, 1 14, respectively). The shaft 102 is rotatably mounted within the housing 106 and is rotatable relative to the casing 108 about the drive axis 1 10.

[0099] In the example illustrated, the first end cap 1 12 includes a first stator disc 1 12a (also referred to as upstream stator disc 1 12a) fixed relative to the casing 108, and the second end cap 1 14 includes a second stator disc 1 14a (also referred to as downstream stator disc 1 14a) fixed relative to the casing 108. In the example illustrated, the first and second stator discs 1 12a, 1 14a are fixed relative to the casing 108 by a key. The key is bolted to the casing 108 and extends into notches provided in the outer surfaces of the first and second stator discs 1 12a, 1 14a. In the example illustrated, the first end cap 1 12 includes a first rotor disc 1 12b (also referred to as upstream rotor disc 1 12b) that is fixed to rotate with the shaft 102 about the drive axis 1 10, and the second end cap 1 14 includes a second rotor disc 1 14b (also referred to as downstream rotor disc 1 14b) that is fixed to rotate with the shaft 102 about the drive axis 1 10. In the example illustrated, the first rotor disc 1 12b is radially inward of the first stator disc 1 12a, and the second rotor disc 1 14b is radially inward of the second stator disc 1 14a. In the example illustrated, the first stator disc 1 12a axially overlaps the first rotor disc 1 12b, and the second stator disc 1 14a axially overlaps the second rotor disc 1 14b.

[00100] In the example illustrated, the shaft 102 is rotatably supported by a pair of bearing assemblies 1 16a, 1 16b mounted to the housing 106. The first bearing assembly 1 16a includes a first bearing housing 1 18a mounted to the housing 106 outboard of the first end cap 1 12 and fixed relative to the casing 108, and the second bearing assembly 1 16b includes a second bearing housing 1 18b mounted to the housing 106 outboard of the second end cap 1 14 and fixed relative to the casing 108. Each bearing housing 1 18a, 1 18b houses a respective bearing 120a, 120b (see also Figure 3) rotatably supporting the shaft 102. Each bearing housing 1 18a, 1 18b includes a plurality of fluid flow passages 1 19. In the example illustrated, the fluid flow passages 1 19 are radially intermediate outer surfaces of the bearing housings 1 18a, 1 18b and inner surfaces of the casing 108. The bearing assemblies 1 16a, 1 16b can also axially support the end caps (and the vanes extending between them) in position along the length of the shaft 102. [00101 ] In the example illustrated, the motor 100 includes an annular passage 122 within the housing 106. The annular passage 122 is radially intermediate the shaft 102 and the casing 108 (see also Figure 6a), and is bounded axially by the first and second end caps 1 12, 1 14 (see also Figure 4).

[00102] In the example illustrated, the motor 100 includes at least one inlet in the housing 106 for conducting fluid into the annular passage 122, and at least one outlet in the housing 106 for evacuating fluid from the annular passage 122. In the example illustrated, the motor 100 includes two inlets 124a, 124b in the housing 106 for conducting fluid into the annular passage 122, and two outlets 126a, 126b in the housing 106 for evacuating fluid from the annular passage 122 (see also Figure 3). The inlets 124a, 124b extend axially through the first end cap 1 12, and the outlets 126a, 126b extend axially through the second end cap 1 14. In the example illustrated, the inlets 124a, 124b extend axially through and are fixed relative to the first stator disc 1 12a, and the outlets 126a, 126b extend axially through and are fixed relative to the second stator disc 1 14a. The inlets 124a, 124b and the outlets 126a, 126 are spaced circumferentially apart, with the outlets 126a, 126b circumferentially interposed between the inlets 124a, 124b.

[00103] Referring to Figure 4, in the example illustrated, the motor 100 includes two stator vanes 130a, 130b extending axially across the passage 122. Referring to Figure 3, each stator vane 130a, 130b is pivotable about a respective stator vane axis 131 a, 131 b fixed relative to the casing 108 (see also Figure 6a). The stator vane axes 131 a, 131 b pass through the passage 122 and extend parallel to the drive axis 1 10, and in the example illustrated, are spaced equally apart about the drive axis 1 10. Referring to Figures 6a and 6b, each stator vane 130a, 130b is pivotable about its stator vane axis 131 a, 131 b between a stator vane closed position (shown in Figure 6a) for inhibiting circumferential fluid flow in the passage 122 across the respective stator vane 130a, 130b, and a stator vane open position (shown in Figure 6b).

[00104] The stator vanes 130a, 130b are similar to one another, and for simplicity, only the stator vane 130a will be described in detail. Referring to Figure 7a, in the example illustrated, the stator vane 130a is pivotally supported by the first and second stator discs 1 12a, 1 14a (shown transparent in Figure 7a) for pivoting about the stator vane axis 131 a. The stator vane 130a includes stator vane pins 133 projecting axially from axial endfaces of the stator vane 130a along the stator vane axis 131 a. The stator vane pins 133 are received in respective stator vane apertures 1 13 (see Figure 3) in the first and second stator discs 1 12a, 1 14a for pivotally supporting the stator vane 130a. [00105] Referring to Figure 6a, the stator vane 130a has a stator vane height bounded by a stator vane root edge 132 and an opposed stator vane tip edge 134. When the stator vane 130a is in the stator vane closed position, the stator vane root edge 132 is proximate the casing 108 and the stator vane tip edge 134 is proximate the shaft 102. In the example illustrated, the stator vane axis 131 a is intermediate the stator vane tip edge 134 and the stator vane root edge 132, and is nearer the stator vane root edge 132 in the example illustrated.

[00106] In some examples, the stator vane tip edge 134 can comprise a stator vane tip seal surface for engaging a rotor engagement surface fixed relative to the shaft 102 in sealed sliding fit when the stator vane 130 is in the closed position. In the example illustrated, the rotor engagement surface comprises a portion of an outer surface of the shaft 102. The stator vane seal tip surface can comprise a deformable material affixed to the stator vane.

[00107] Referring to Figures 6a and 6b, in the example illustrated, when the stator vane 130a pivots from the stator vane closed position (Figure 6a) toward the stator vane open position (Figure 6b), the stator vane tip edge 134 pivots about the stator vane axis 131 a in a stator vane first direction 135a toward the casing 108. When the stator vane 130a pivots from the stator vane open position toward the stator vane closed position, the stator vane tip edge 134 pivots about the stator vane axis 131 a in a stator vane second direction 135a toward the shaft 102. The stator vane second direction 135b is opposite the stator vane first direction 135a. When the stator vane 130a is in the stator vane closed position, a stator vane stop surface fixed to the stator vane 130 abuts a stator abutment surface fixed relative to the casing 108 to inhibit further pivoting of the stator vane 130a in the stator vane second direction 135b. In the example illustrated, the stator vane stop surface comprises at least a portion of the stator vane root edge 132, and the stator abutment surface comprises a portion of an inner surface of the casing 108.

[00108] In the example illustrated, the stator vane 130a has a stator vane thickness bounded by a stator vane leading face 136 and an opposed stator vane trailing face 138. The stator vane leading and trailing faces 136, 138 are bounded by the stator vane root and tip edges 132, 134. Referring to Figure 6a, when the stator vane 130a is in the stator vane closed position, the stator vane leading face 136 extends radially across the passage 122 and is directed generally toward the power direction 104, and the trailing face 138 extends radially across the passage 122 and is directed generally toward a reverse direction opposite the power direction 104. Referring to Figure 6b, when the stator vane 130a is in the stator vane open position, the stator vane leading face 136 is directed generally radially outwardly toward the casing 108, and the stator vane trailing face 138 is directed generally radially inwardly toward the shaft 102.

[00109] Referring to Figure 5, in the example illustrated, the motor 100 includes two rotor vanes 140a, 140b extending axially across the passage 122. Referring to Figure 3, each rotor vane 140a, 140b is pivotable about a respective rotor vane axis 141 a, 141 b fixed relative to the shaft 102 (see also Figure 6a). The rotor vane axes 141 a, 141 b pass through the passage 122 and extend parallel to the drive axis 1 10, and in the example illustrated, are spaced equally apart about the drive axis 1 10. Referring to Figures 6a and 6b, each rotor vane 140a, 140b is pivotable about its rotor vane axis 141 a, 141 b between a rotor vane closed position (shown in Figure 6a) for inhibiting circumferential fluid flow in the passage 122 across the respective rotor vane 140a, 140b, and a rotor vane open position (shown in Figure 6b).

[001 10] The rotor vanes 140a, 140b are similar to one another, and for simplicity, only the rotor vane 140a will be described in detail. Referring to Figure 5, in the example illustrated, the rotor vane 140a is pivotally supported by the first and second rotor discs 1 12b, 1 14b for pivoting about the rotor vane axis 141 a (see also Figure 7b). The rotor vane 140a includes rotor vane pins 143 projecting axially from axial endfaces of the rotor vane 140a along the rotor vane axis 141 a. The rotor vane pins 143 are received in respective rotor vane apertures 1 15 in the first and second rotor discs 1 12b, 1 14b for pivotally supporting the rotor vane 140a.

[001 1 1 ] Referring to Figure 6a, the rotor vane 140a has a rotor vane height bounded by a rotor vane root edge 142 and an opposed rotor vane tip edge 144. When the rotor vane 140a is in the rotor vane closed position (Figure 6a), the rotor vane root edge 142 is proximate the shaft 102 and the rotor vane tip edge 144 is proximate the casing 108. The rotor vane axis 141 a is intermediate the rotor vane tip edge 144 and the rotor vane root edge 142, and is nearer the rotor vane root edge 142 in the example illustrated.

[001 12] Referring to Figures 6a and 6b, in the example illustrated, when the rotor vane 140a pivots from the rotor vane closed position (Figure 6a) toward the rotor vane open position (Figure 6b), the rotor vane tip edge 144 pivots about the rotor vane axis 141 a in a rotor vane first direction 145a toward the shaft 102. When the rotor vane 140a pivots from the rotor vane open position toward the rotor vane closed position, the rotor vane tip edge 144 pivots about the rotor vane axis 141 a in a rotor vane second direction 145b toward the casing 108. The rotor vane second direction 145b is opposite the rotor vane first direction 145a. In the example illustrated the rotor vane first direction 145a corresponds to the stator vane first direction 135a, and the rotor vane second direction 145b corresponds to the stator vane second direction 135b. When the rotor vane 140a is in the rotor vane closed position, a rotor vane stop surface fixed to the rotor vane 140 abuts a rotor abutment surface fixed relative to the shaft 102 to inhibit further pivoting of the rotor vane 140a in the rotor vane second direction 145b. In the example illustrated, the rotor vane stop surface comprises at least a portion of the rotor vane root edge 142, and the rotor abutment surface comprises a portion of the outer surface of the shaft 102. [001 13] In the example illustrated, the rotor vane 140a has a rotor vane thickness bounded by a rotor vane leading face 146 and an opposed rotor vane trailing face 148. The rotor vane trailing and leading faces 146, 148 are bounded by the rotor vane root and tip edges 142, 144. When the rotor vane 140a is in the rotor vane closed position, the rotor vane leading face 146 extends radially across the passage 122 and is directed generally toward the power direction 104, and the rotor vane trailing face 148 extends radially across the passage 122 and is directed generally toward the reverse direction. Referring to Figure 6b, when the rotor vane 140a is in the rotor vane open position, the rotor vane trailing face 148 is directed generally radially inwardly toward the shaft 102, and the rotor vane leading face 146 is directed generally radially outwardly toward the casing 108. [001 14] In some examples, the rotor vane tip edge 144 can comprise a rotor vane tip seal surface for engaging a stator engagement surface fixed relative to the casing 108 in sealed sliding fit when the rotor vane 140 is in the closed position. The stator engagement surface can comprise at least a portion of the inner surface of the casing 108. The rotor vane seal tip surface can comprise a deformable material affixed to the rotor vane.

[001 15] Referring to Figure 6a, when in respective closed positions, the stator vanes 130a, 130b and the rotor vanes 140a, 140b separate the passage 122 into two circumferentially expanding chambers 150a, 150b, and two circumferentially collapsing chambers 160a, 160b that are spaced circumferentially apart from the expanding chambers 150a, 150b. In the example illustrated, the collapsing chambers 160a, 160b are interposed between the expanding chambers 150a, 150b. In the example illustrated, the expanding chambers 150a, 150b are bounded circumferentially by the trailing faces 148 of the rotor vanes 140a, 140b and the leading faces 136 of the stator vanes 130a, 130b. The collapsing chambers 160a, 160b are bounded circumferentially by the leading faces 146 of the rotor vanes 140a, 140b and the trailing faces 138 of the stator vanes 130a, 130b. Each of the expanding and collapsing chambers 150a, 150b, 160a, 160b are bounded axially by inner surfaces of the end caps 1 12, 1 14, and radially by an outer surface of the shaft 102 and an inner surface of the casing 108. [001 16] In the example illustrated, the expanding chambers 150a, 150b are in fluid communication with the inlets 124a, 124b for receiving pressurized fluid. The pressurized fluid can bear against the trailing faces 148 of the rotor vanes 140a, 140b to urge rotation of the shaft 102 in the power direction 104. The collapsing chambers 160a, 160b are in fluid communication with the outlets 126a, 126b for evacuating fluid from the collapsing chambers 160a, 160b during rotation of the shaft 102 in the power direction 104. As the shaft 102 rotates in the power direction 104, the leading faces 146 of the rotor vanes 140a, 140b bear against fluid in the collapsing chambers 160a, 160b to urge evacuation of the fluid via the outlets 126a, 126b.

[001 17] Referring to Figure 6b, when the rotor vanes 140a, 140b and the stator vanes 130a, 130b are in respective open positions, the rotor vanes 140a, 140b can move circumferentially past stator vanes 130a, 130b during rotation of the shaft 102. In the example illustrated, the rotor vane axes 141 a, 141 b are radially offset from the stator vane axes 131 a, 131 b. In the example illustrated, the rotor vane axes 141 a, 141 b are offset radially inwardly toward the shaft 102 and the stator vane axes 131 a, 131 b are offset radially outwardly toward the casing 108. Referring to Figure 6b, when the rotor vanes 140a, 140b and the stator vanes 130a, 130b are in respective open positions, the stator vane trailing faces 138 are spaced radially apart from the shaft 102 by a radially inner passage gap 170a, and the rotor vane leading faces 146 are spaced radially apart from the casing 108 by a radially outer passage gap 170b. The radially inner and radially outer passage gaps 170a, 170b are sized to accommodate circumferential movement of the rotor vanes 140a, 140b past the stator vanes 130a, 130b when the rotor and stator vanes are in respective open positions.

[001 18] Referring to Figure 6b, in the example illustrated, when the rotor and stator vanes 130, 140 are in respective open positions, the inlets 124a, 124b are in fluid communication with the outlets 126a, 126b, and the motor may generate insufficient torque for rotating the shaft 102 in the power direction 104 to move the rotor vanes 140 past the stator vanes 130. In some examples, an external energy source can rotate the shaft 102 in the power direction 104 to move the rotor vanes 140 past the stator vanes 130 to an angular position in which the rotor and stator vanes can pivot to respective closed positions. In some examples, two or more rotary motors similar to the rotary motor 100 may be stacked in series to generate continuous torque. For example, a first rotary motor and a second rotary motor may be coupled to a shaft. The first and second motors can be circumferentially offset from one another, such that when the rotor and stator vanes of the one of the motors are in respective open positions (i.e. the rotor vanes are moving past the stator vanes), the rotor and stator vanes of the other one of the motors are in respective closed positions and generating torque on the shaft to rotate the shaft in the power direction (and move the open rotor vanes circumferentially past the open stator vanes so that the rotor and stator vanes can pivot to respective closed positions). [001 19] In some examples, the rotor and stator vanes 130, 140 may be moved from the closed position to the open position by contact between the rotor and stator vanes during rotation of the shaft 102 (see e.g. Figure 17d). For example, the leading face of the rotor vane may engage the trailing face of the stator vane during rotation of the shaft, which may urge the rotor and stator vanes towards respective open positions. In some examples, the rotor and stator vanes 130, 140 may be moved from the open position to the closed position by the force exerted by pressurized fluid in the expanding chamber bounded by the respective rotor and stator vanes. In some examples, movement of the rotor and stator vanes between open and closed positions may be controlled mechanically, for example, by a vane pivoting mechanism. The vane pivoting mechanisms may include, for example, gear mechanisms, mechanical linkages, springs, and/or cams and cam followers for moving the rotor and stator vanes between the open and closed positions.

[00120] Referring to Figure 3, the motor 100 includes a vane pivoting mechanism for pivoting the stator and rotor vanes 130, 140 between respective open and closed positions at predetermined angular positions of the shaft 102. In the example illustrated, the vane pivoting mechanism includes a stator vane pivoting mechanism 180 for pivoting the stator vanes 130a, 130b about respective stator vane axes 131 a, 131 b, and a rotor vane pivoting mechanism 190 for pivoting the rotor vanes 140a, 140b about respective rotor vane axes 141 a, 141 b. For simplicity, the pivoting mechanism 180 will be described only with respect to the stator vane 130a, and the pivoting mechanism 190 will be described only with respect to the rotor vane 140a.

[00121 ] Referring to Figure 7b, the rotor vane pivoting mechanism 190 includes a rotor vane actuator 192 and a rotor vane crank arm 194 fixed to and extending radially from one of the rotor vane pins 143. The rotor vane actuator 192 urges an outer end of the rotor vane crank arm 194 toward a rotor vane crank arm first radial position (shown in Figure 9a) to urge the rotor vane 141 a toward the rotor vane closed position. The rotor vane actuator 192 urges the outer end of the rotor vane crank arm 194 toward a rotor vane crank arm second radial position (shown in Figure 9b) to urge the rotor vane toward the rotor vane open position. In the example illustrated, the rotor vane crank arm first radial position is radially outward of the rotor vane crank arm second radial position. [00122] In the example illustrated, a rotor vane cam follower 196 is fixed to the outer end of the rotor vane crank arm 194. The rotor vane cam follower 196 can be, for example, a roller bearing. Referring to Figures 8a and 9a, the rotor vane actuator 192 includes two rotor vane first cam surfaces 198 that are directed radially outwardly and fixed relative to the casing 108. Each rotor vane first cam surface 198 can engage the rotor vane cam follower 196 at a respective predetermined angular position of the shaft 102 to push the radially outer end of the rotor vane crank arm 194 toward the rotor vane crank arm first radial position (and urge the rotor vane 140a toward the closed position). Referring to Figures 8b and 9b, in the example illustrated, the rotor vane actuator 192 further includes two rotor vane second cam surfaces 199 directed radially inwardly and fixed relative to the casing 108. Each rotor vane second cam surface 199 can engage the rotor vane cam follower 196 at a respective predetermined angular position of the shaft 102 to push the radially outer end of the rotor vane crank arm 194 toward the rotor vane crank arm second radial position (and urge the rotor vane 140a toward the open position). In the example illustrated, the rotor vane first and second cam surfaces 198, 199 are circumferentially spaced apart from one another, and the rotor vane first cam surfaces 198 are interposed between the rotor vane second cam surfaces 199.

[00123] Referring to Figure 7a, the stator vane pivoting mechanism 180 includes a stator vane actuator 182 and a stator vane crank arm 184 fixed to and extending radially from one of the stator vane pins 133. The stator vane actuator 182 urges an outer end of the stator vane crank arm 184 toward a stator vane crank arm first radial position (shown in Figure 10a) to urge the stator vane 130a toward the stator vane closed position. The stator vane actuator 182 urges the outer end of the stator vane crank arm 184 toward a stator vane crank arm second radial position (shown in Figure 10b) to urge the stator vane 130a toward the stator vane open position. In the example illustrated, the stator vane crank arm first radial position is radially inward of the stator vane crank arm second radial position.

[00124] In the example illustrated, a stator vane cam follower 186 is fixed to the outer end of the stator vane crank arm 184. The stator vane cam follower 186 can be, for example, a roller bearing. Referring to Figures 8a and 10a, the stator vane actuator 182 includes two stator vane first cam surfaces 188 that are directed radially inwardly and fixed to rotate with the shaft 102. Each stator vane first cam surface 188 can engage the stator vane cam follower 186 at a respective predetermined angular position of the shaft 102 to push the radially outer end of the stator vane crank arm 184 toward the stator vane crank arm first radial position (and urge the stator vane 130a toward the closed position). Referring to Figures 8b and 10b, the stator vane actuator 182 further includes two radially outwardly directed stator vane second cam surfaces 189 fixed to rotate with the shaft 102. Each stator vane second cam surface 189 can engage the stator vane cam follower 186 at a respective predetermined angular position of the shaft 102 to push the radially outer end of the stator vane crank arm 184 toward the stator vane crank arm second radial position (and urge the stator vane 130a toward the stator vane open position). In the example illustrated, the stator vane first and second cam surfaces 188, 189 are circumferentially spaced apart from one another, and the rotor vane first cam surfaces 188 are interposed between the rotor vane second cam surfaces 189. [00125] In the example illustrated, the rotor and stator vanes 130, 140 can lock in the closed position upon reverse rotation of the shaft 102 relative to the casing 108 (i.e. either by rotating the shaft 102 in the reverse rotational direction with the casing 108 fixed, or by rotating the casing 108 in the power direction and holding the shaft 102 fixed). This can advantageously transfer torque during such rotation through the vane pins rather than through interference between the cam and cam follower, which may be mechanically weaker than the connection provided by the vane pins. In some examples, it may be desirable to have the motor free-wheel when the shaft rotates in the reverse direction (second rotational direction) relative to the casing 108.

[00126] In some examples, the open position of the stator vanes and rotor vanes may be limited to a particular angular position about their respective axes that is sufficient to accommodate movement of the rotor and stator vanes past one another during rotation of the shaft, but limits overtravel of the vanes past this position. Limiting the overtravel may help prevent undesired interference or jamming of the vanes during non-steady state operating conditions (e.g. during start-up), and can help to limit the rotational displacement required to return the vanes to the closed position, which may reduce stresses imposed on the vane pivoting mechanism(s) and may increase power and torque output.

[00127] In some example, the maximum open position of the stator vanes 130 can be defined by contact of the leading face 136 of the stator vane 130 with the inner surface of the casing 108. Similarly, the maximum open position of the rotor vanes 140 can be defined by contact of the trailing face 148 with the shaft 102. In some examples, the maximum open positions can be defined by abutment surfaces provided in the vane pivoting mechanisms 180, 190.

[00128] Referring to Figure 1 1 , an example of another rotor vane 1 140a for use with the rotary motor 100 is illustrated. The rotor vane 1 140a has similarities to the rotor vane 140a, and like features are identified by like reference characters, incremented by 1000.

[00129] In the example illustrated, the rotor vane 1 140a has a rotor vane height bounded by a rotor vane root edge 1 142 and an opposed rotor vane tip edge 1 144. When the rotor vane 1 140a is in the rotor vane closed position (Figure 1 1 ), the rotor vane root edge 1 142 is proximate the shaft 102 and the rotor vane tip edge 1 144 is proximate the casing 108. Referring to Figure 1 1 a, in the example illustrated, when the rotor vane 1 140a is in the rotor vane closed position, the rotor vane tip edge 1 144 is spaced radially apart from the casing 108 by a rotor vane clearance gap 1200 for permitting interference free movement of the rotor vane tip edge 1 144 relative to the casing 108 during rotation of the shaft 102.

[00130] In the example illustrated, the rotor vane 1 140a has a rotor vane thickness bounded by a rotor vane leading face 1 146 and an opposed rotor vane trailing face 1 148. Referring to Figure 12, when the rotor vane 1 140a is in the rotor vane open position, the rotor vane trailing face 1 148 is directed generally radially inwardly toward the shaft 102, and the rotor vane leading face 1 146 is directed generally radially outwardly toward the casing 108. Referring to Figure 12a, when the rotor vane 1 140a is in the rotor vane open position, the rotor vane trailing face 1 148 is spaced radially apart from the shaft by a rotor vane flow gap 1202. The rotor vane flow gap 1202 can permit circumferential fluid flow in the passage 122 across the rotor vane 1 140a. This may help wash away particles that may accumulate adjacent the rotor vane root edge 1 142 when the rotor vane 1 140a is in the rotor vane closed position, which may help improve operational efficiency of the motor and reduce the likelihood of the motor jamming due to a buildup of particles within the passage 122. [00131 ] Referring to Figure 13, an example of another stator vane 1 130a for use with the rotary motor 100 is illustrated. The stator vane 1 130a has similarities to the stator vane 130a, and like features are identified by like reference characters, incremented by 1000.

[00132] In the example illustrated, the stator vane 1 130a has a stator vane height bounded by a stator vane root edge 1 132 and an opposed stator vane tip edge 1 134. When the stator vane 1 130a is in the stator vane closed position (Figure 13), the stator vane root edge 1 132 is proximate the casing 108 and the stator vane tip edge 1 134 is proximate the shaft 102. Referring to Figure 13a, in the example illustrated, when the stator vane 1 130a is in the stator vane closed position, the stator vane tip edge 1 134 is spaced radially apart from the shaft 102 by a stator vane clearance gap 1204 for permitting interference free rotation of the shaft 102 relative to the stator vane tip edge 1 134.

[00133] In the example illustrated, the stator vane 1 130a has a stator vane thickness bounded by a stator vane leading face 1 136 and an opposed stator vane trailing face 1 138. Referring to Figure 14, when the stator vane 1 130a is in the stator vane open position, the stator vane trailing face 1 138 is directed generally radially inwardly toward the shaft 102, and the stator vane leading face 1 136 is directed generally radially outwardly toward the casing 108. Referring to Figure 14a, when the stator vane 1 130a is in the stator vane open position, the stator vane leading face 1 136 is spaced radially apart from the casing 108 by a stator vane flow gap 1206. The stator vane flow gap 1206 can permit circumferential fluid flow in the passage 122 across the stator vane 1 130a. This may help wash away particles that may accumulate adjacent the stator vane root edge 1 132 when the stator vane 1 130a is in the stator vane closed position, which may help improve operational efficiency of the motor and reduce the likelihood of the motor jamming due to a buildup of particles within the passage 122. [00134] Referring to Figure 15, an example of another rotary motor 2100 is illustrated. The motor 2100 has similarities to the motor 100, and like features are identified by like reference characters, incremented by 2000.

[00135] Referring to Figure 16, in the example illustrated, the rotary motor 2100 includes a housing 2106 having a cylindrical casing 2108 extending along a drive axis 21 10 between axially spaced apart first and second end caps 21 12, 21 14. A shaft 2102 is rotatably mounted within the housing 2106 and is rotatable relative to the casing 2108 about the drive axis 21 10.

[00136] In the example illustrated, the first end cap 21 12 includes a radially outer first stator disc 21 12a fixed relative to the casing 2108, and a radially inner first rotor disc 21 12b that is rotatable relative to the casing 2108 about the drive axis 21 10. The second end cap 21 14 includes a radially outer second stator disc 21 14a fixed relative to the casing 2108 and a radially inner second rotor disc 21 14b that is rotatable relative to the casing 2108 about the drive axis 21 10. Each of the first and second rotor discs 21 12b, 21 14b is fixed to rotate with the shaft 2102 about the drive axis 21 10.

[00137] In the example illustrated, the shaft 2102 is rotatably supported by a pair of bearing assemblies 21 16a, 21 16b mounted to the housing 2106. Each bearing assembly 21 16a, 21 16b includes a plurality of flow passages 21 19.

[00138] In the example illustrated, the motor 2100 includes an annular passage 2122 within the housing 2106 (see Figure 17a). The annular passage 2122 is radially intermediate the shaft 2102 and the casing 2108, and is bounded axially by the first and second end caps 21 12, 21 14. In the example illustrated, the motor 2100 includes two inlets 2124a, 2124b in the housing 2106 for conducting fluid into the annular passage 2122, and two outlets 2126a, 2126b in the housing 2106 for evacuating fluid from the annular passage 2122 (see also Figure 17a). The inlets 2124a, 2124b extend axially through the first end cap 21 12, and the outlets 2126a, 2126b extend axially through the second end cap 21 14. In the example illustrated, the inlet 2124a extends axially through and is fixed relative to the first stator disc 21 12a, and the inlet 2124b extends axially through and is fixed relative to the first rotor disc 21 12b. The outlet 2126a extends axially through and is fixed relative to the second stator disc 21 14a, and the outlet 2126b extends axially through and is fixed relative to the second rotor disc 21 14b.

[00139] In the example illustrated, the motor 2100 includes a stator vane 2130 extending axially across the passage 2122. Referring to Figure 17a, the stator vane 2130 is pivotable about a stator vane axis 2131 fixed relative to the casing 2108. The stator vane axis 2131 passes through the passage 2122 and extends parallel to the drive axis 21 10. The stator vane 2130 is pivotable about the stator vane axis 2131 between a stator vane closed position (shown in Figure 17a) for inhibiting circumferential fluid flow in the passage 2122 across the stator vane 2130, and a stator vane open position (shown in Figure 17e).

[00140] Referring to Figure 16, in the example illustrated, the motor 2100 includes a rotor vane 2140 extending axially across the passage 2122. Referring to Figure 17a, the rotor vane 2140 is pivotable about a rotor vane axis 2141 fixed relative to the shaft 2102. The rotor vane axis 2141 passes through the passage 2122 and extends parallel to the drive axis 21 10. Referring to Figure 17a, the rotor vane 2140 is pivotable about the rotor vane axis 2141 between a rotor vane closed position (shown in Figure 17a) for inhibiting circumferential fluid flow in the passage 2122 across the rotor vane 2140, and a rotor vane open position (shown in Figure 17d).

[00141 ] Referring to Figure 17a, when in respective closed positions, the stator and rotor vanes 2130, 2140 separate the passage 2122 into a circumferentially expanding chamber 2150 and a circumferentially collapsing chamber 2160 that is spaced circumferentially apart from the expanding chamber 2150. Referring to Figure 17b, in the example illustrated, the expanding chamber 2150 is bounded circumferentially by a trailing face 2148 of the rotor vane 2140 and a leading face 2136 of the stator vane 2130. The collapsing chamber 2160 is bounded circumferentially by the leading face 2146 of the rotor vane 2140 and the trailing face 2138 of the stator vane 2130.

[00142] In the example illustrated, the expanding chamber 2150 is in fluid communication with the inlets 2124a, 2124b for receiving pressurized fluid. The pressurized fluid can bear against the trailing face 2148 of the rotor vane 2140 to urge rotation of the shaft 2102 in the power direction 2104. The collapsing chamber 2160 is in fluid communication with the outlets 2126a, 2126b for evacuating fluid from the collapsing chamber 2160 during rotation of the shaft 2102 in the power direction 2104. As the shaft 2102 rotates in the power direction 2104, the leading face 2146 of the rotor vane 2140 bears against fluid in the collapsing chamber 2160 to urge evacuation of the fluid via the outlets 2126a, 2126b.

[00143] Referring to Figure 17d, when the rotor and stator vanes 2130, 2140 are in respective open positions, the rotor vane 2140 can move circumferentially past the stator vane 2130 during rotation of the shaft 2102. In the example illustrated, the rotor vane axis 2141 is radially offset from the stator vane axis 2131 . In the example illustrated, the rotor vane axis 2141 is offset radially inwardly toward the shaft 2102 and the stator vane axis 2131 is offset radially outwardly toward the casing 2108. When the rotor and stator vanes 2130, 2140 are in respective open positions, the stator vane trailing face 2138 is spaced radially apart from the shaft 2102 and the rotor vane leading face 2146 is spaced radially apart from the casing 2108 to permit circumferential movement of the rotor vane 2140 past the stator vane 2130.

[00144] Referring to Figure 18a, an example of another rotary motor 3100 is illustrated. The motor 3100 has similarities to the motor 100, and like features are identified by like reference characters, incremented by 3000. [00145] In the example illustrated, the motor 3100 includes three stator vanes 3130a, 3130b, 3130c, each pivotable about a respective stator vane axis 3131. The stator vane axes 3131 are spaced equally apart about the drive axis 31 10. Each stator vane 3130 is associated with a respective inlet 3124 and a respective outlet 3126, with the respective inlet 3124 and the respective outlet 3126 disposed on circumferentially opposite sides of the stator vane 3130 when the stator vane 3130 is in the stator vane closed position. In the example illustrated, at any angular position of the shaft 3102, at least one of the stator vanes 3130a, 3130b, 3130c is in the stator vane closed position, and includes a trailing face 3138 circumferentially bounding a collapsing chamber and a leading face 3136 circumferentially bounding a expanding chamber within the passage 31 12. [00146] In the example illustrated, the motor 3100 further includes two rotor vanes 3140a, 3140b fixed to rotate with the shaft 3102, each pivotable about a respective rotor vane axis 3141 . The sequence of rotation of the shaft 3102 in a first rotational direction (counter-clockwise in the Figures) is illustrated in Figures 18a-18f. [00147] Referring to Figure 19A, an example of another rotary motor 4100 is illustrated. The motor 4100 has similarities to the motor 100, and like features are identified by like reference characters, incremented by 4000.

[00148] In the example illustrated, the rotary motor 4100 includes a housing 4106 having a cylindrical casing 4108 (shown in phantom lines in Figure 19A) extending between axially spaced apart first and second end caps 41 12, 41 14. A shaft 4102 is rotatably mounted within the housing 4106. In the example illustrated, the first end cap 41 12 includes a radially outer first stator disc 41 12a and a radially inner first rotor disc 41 12b, and the second end cap 41 14 includes a radially outer second stator disc 41 14a and a radially inner second rotor disc 41 14b. At least one inlet 4124 extends through the first end cap 41 12 for conducting fluid into an annular passage 4122 within the housing 4106. At least one outlet 4126 extends through the second end cap 41 14 for evacuating fluid from the annular passage 4122.

[00149] Referring to Figure 20, in the example illustrated, the at least one inlet 4124 comprises a first inlet 4124a extending through and fixed relative to the first stator disc 41 12a, and a second inlet 4124b extending through and fixed to rotate with the first rotor disc 41 12b. In the example illustrated, the at least one outlet 4126 comprises a first outlet 4126a extending through and fixed relative to the second stator disc 41 14a, and a second outlet 4126b extending through and fixed to rotate with the second rotor disc 41 14b. [00150] In the example illustrated, each of the inlet 4124 and the outlet 4126 extend axially through respective end caps 41 12, 41 14. In some examples, one or both of the inlet 4124 and the outlet 4126 can extend radially through the casing 41 08. In some examples, the shaft 4102 can comprise an internal shaft conduit for conducting fluid, and one or both of the inlet 4124 and the outlet 4126 can extend radially through the shaft 4102 for conducting fluid between the passage 4122 and the shaft conduit. [00151 ] In the example illustrated, the motor 4100 includes a stator vane 4130 and a rotor vane 4140, each pivotable about a respective vane axis 4131 , 4141 between respective open and closed positions. Referring to Figure 21 , when in respective closed positions, the stator and rotor vanes 4130, 4140 separate the passage 4122 into a circumferentially expanding chamber 4150 in fluid communication with the inlets 4124 for receiving pressurized fluid, and a circumferentially collapsing chamber 4160 in fluid communication with the outlets 4126 for evacuating fluid. In Figure 21 , the stator vane 4130 is shown in the closed position and the rotor vane 4140 is shown in a partially open position. [00152] Referring to Figure 20, in the example illustrated, the first end cap 41 12 includes a first end cap seal 4212 for inhibiting leakage of fluid into the collapsing chamber 4160. In the example illustrated, the first end cap seal 4212 includes a first disc seal 4212a radially intermediate the first stator disc 41 12a and the first rotor disc 41 12b for sealing the interface between at least a portion of the radially outer surface of the first rotor disc 41 12b and at least a portion of the radially inner surface of the first stator disc 41 12a. In the example illustrated, the first end cap seal 4212 further includes a first casing seal 4212b radially intermediate the first stator disc 41 12a and the casing 4108 for sealing the interface between at least a portion of a radially outer surface of the first stator disc 41 12a and at least a portion of the radially inner surface of the casing 4108.

[00153] In the example illustrated, the second end cap 41 14 includes a second end cap seal 4214 for inhibiting leakage of fluid out from the expanding chamber 4150. In the example illustrated, the second end cap seal 4214 includes a second disc seal 4214a radially intermediate the second stator disc 41 14a and the second rotor disc 41 14b for sealing the interface between at least a portion of the radially outer surface of the second rotor disc 41 14b and at least a portion of the radially inner surface of the second stator disc 41 14a. In the example illustrated, the second end cap seal 4214 further includes a second casing seal 4214b radially intermediate the second stator disc 41 14a and the casing 4108 for sealing the interface between at least a portion of a radially outer surface of the second stator disc 41 14a and at least a portion of the radially inner surface of the casing 4108. [00154] Referring to Figure 21 , in the example illustrated, the stator vane 4130 has a stator vane height bounded by a stator vane root edge 4132 and an opposed stator vane tip edge 4134. In the example illustrated, the stator vane tip edge 4134 includes a stator vane tip seal surface 4216. In the example illustrated, the stator vane tip seal surface 4216 engages a rotor engagement surface 4217 fixed relative to the shaft 4102 in sealed sliding fit when the stator vane 4130 is in the closed position to inhibit circumferential fluid flow across the stator vane 4130. In the example illustrated, the rotor engagement surface 4217 comprises at least a portion of an outer surface of the shaft 4102. [00155] In the example illustrated, the rotor vane 4140 has a rotor vane height bounded by a rotor vane root edge 4142 and an opposed rotor vane tip edge 4144. In the example illustrated, the rotor vane tip edge 4144 includes a rotor vane tip seal surface 4218. The rotor vane tip seal surface 4218 engages a stator engagement surface 4219 fixed relative to the casing 4108 in sealed sliding fit when the rotor vane 4140 is in the closed position to inhibit circumferential fluid flow across the rotor vane 4140. In the example illustrated, the stator engagement surface 4219 comprises at least a portion of an inner surface of the casing 4108.

[00156] In the example illustrated, the stator vane 4130 includes a stator vane seal 4220, and the rotor vane 4140 includes a rotor vane seal 4222. In the example illustrated, each of the seals 4220, 4222 extends axially across the passage 4122. Each of the seals 4220, 4222 can be spring loaded for pushing a respective stator vane and rotor vane tip seal surface 4216, 4218 against a respective rotor and stator engagement surface 4217, 4219 when the rotor and stator vanes are in the closed positions. In the example illustrated, each of the seals 4220, 4222 includes a U-shaped flat spring 4224 enclosed in a plastic wrap 4226. In the example illustrated, the seal surfaces 4216, 4218 comprise a portion of an outer surface of the plastic wrap 4226. The plastic wrap can comprise, for example, Polytetrafluoroethylene (PTFE) or Polyether ether ketone (PEEK). In some examples, an interior 4228 of the spring 4224 can be filled with a deformable material to inhibit particles from accumulating within the interior 4228. The deformable material can include, for example, an elastomer. [00157] In some examples, each seal 4220, 4222 can comprise an elastomer coating comprising the respective seal surfaces 4216, 4218. In some examples, an entirety of the outer surface of one or both of the vanes 4130, 4140 can comprise an elastomer coating. In some examples, the outer surface of the shaft 4102 can comprise an elastomer coating for facilitating sealing of the interface between the stator vane tip seal surface 4216 and the rotor engagement surface 4217. In some examples, the inner surface of the casing 4108 can comprise an elastomer coating for facilitating sealing of the interface between the rotor vane tip seal surface 4218 and the stator engagement surface 4219. [00158] In the example illustrated, when the stator vane 4130 is in the stator vane closed position, a stator vane stop surface 4232 fixed to the stator vane 4130 abuts a stator abutment surface 4234 fixed relative to the casing 4108 to inhibit further pivoting of the stator vane 4130. When the stator vane 4130 is in the stator vane open position, the stator vane stop surface 4232 is spaced apart from the stator abutment surface 4234. In the example illustrated, the stator vane stop surface 4232 comprises a portion of a stator vane trailing face 4138 of the stator vane 4130.

[00159] In the example illustrated, the stator vane stop surface 4232 is intermediate the stator vane axis 4131 and the stator vane tip edge 4134. This may help reduce the reaction force exerted on the stator vane 4130 (including the stator vane pins pivotally supporting the stator vane 4130), may help reduce deflection of the stator vane tip edge 4134 relative to the shaft 4102, and may help reduce fluid leakage across the stator vane 4130 when pressurized fluid bears against the stator vane 4130 in the closed position.

[00160] In the example illustrated, the motor 4100 includes a stator block 4236 fixed relative to the casing 4108. In the example illustrated, the stator block 4236 extends axially across the passage 4122, and is proximate the casing 4108. In the example illustrated, the stator abutment surface 4234 comprises a portion of a leading surface of the stator block 4236.

[00161 ] The stator block 4236 can be fixed relative to the casing 4108 via stator block pins 4238. In the example illustrated, a single stator block pin 4238 projects axially from one axial endface of the stator block 4236, and is received in a respective stator block aperture 4239 in the second stator disc 41 14a. In the example illustrated, a pair of stator block pins 4238 project axially from the other axial endface of the stator block 4236, and are received in respective stator block apertures 4239 in the first stator disc 41 12a. The block pins 4238 can facilitate proper orientation and inhibit rotation of the stator block 4236 during installation, and outer surfaces of the stator block 4236 can engage components of the motor 4100 (e.g., the inner surface of the casing 4108) to inhibit rotation of the stator block 4236 during use.

[00162] Referring to Figure 21 , in the example illustrated, when the rotor vane 4140 is in the rotor vane closed position, a rotor vane stop surface 4242 fixed to the rotor vane 4140 abuts a rotor abutment surface 4244 fixed relative to the shaft 4102 to inhibit further pivoting of the rotor vane 4140. When the rotor vane 4140 is in the rotor vane open position, the rotor vane stop surface 4242 is spaced apart from the rotor abutment surface 4244. In the example illustrated, the rotor vane stop surface 4242 comprises a portion of a rotor vane leading face 4146 of the rotor vane 4140.

[00163] In the example illustrated, the rotor vane stop surface 4242 is intermediate the rotor vane axis 4141 and the rotor vane tip edge 4144. This may help reduce the reaction force exerted on the rotor vane 4140 (including the rotor vane pins pivotally supporting the rotor vane 4140), may help reduce deflection of the rotor vane tip edge 4144 relative to the casing 4108, and may help reduce fluid leakage across the rotor vane when pressurized fluid bears against the rotor vane 4140 in the closed position.

[00164] In the example illustrated, the rotor abutment surface 4244 is spaced radially outwardly from an outer diameter of the shaft 4102 by a rotor abutment surface distance 4235. In the example illustrated, the stator abutment surface 4234 is spaced radially inwardly from an inner diameter of the casing 4108 by a stator abutment surface distance 4235. In the example illustrated, the annular passage 4122 has a passage radial extent 4123. In the example illustrated, the passage radial extent 4123 is measured from an outer diameter of the shaft 4102 to an inner diameter of the casing 4108. In the example illustrated, the sum of the rotor abutment surface distance 4245 and the stator abutment surface distance 4235 is less than the passage radial extent 4123.

[00165] In the example illustrated, the motor 4100 includes a rotor block 4246 fixed to rotate with the shaft 4102. In the example illustrated, the rotor block 4246 extends axially across the passage 4122, and is proximate the shaft 4102. In the example illustrated, the rotor abutment surface 4244 comprises a portion of a trailing surface of the rotor block 4246. In the example illustrated, the rotor block 4246 is fixed to rotate with the shaft 4102 via a plurality of rotor block bolts 4248 passing radially through the rotor block 4246 and anchored in the shaft 4102. [00166] In the example illustrated, the rotor block 4246 has a rotor block radial extent 4247 measured radially outwardly from an outer diameter of shaft 4102. In the example illustrated, the stator block 4236 has a stator block radial extent 4237 measured radially inwardly from the inner diameter of the casing 4108. In the example illustrated, a sum of the stator block radial extent 4237 and the rotor block radial extent 4247 is less than the passage radial extent 4123.

[00167] In the example illustrated, the motor 4100 includes a stator vane pivoting mechanism 4180 for pivoting the stator vane 4130 about the stator vane axis 4131 , and a rotor vane pivoting mechanism 4190 for pivoting the rotor vane 4140 about the rotor vane axis 4141 . [00168] In the example illustrated, the stator vane pivoting mechanism 4180 comprises a stator vane actuation surface 4250 fixed to rotate with the shaft 4102. The stator vane actuation surface 4250 contacts the trailing face 4138 of the stator vane 4130 during rotation of the shaft 4102 for urging the stator vane from the closed position to the open position. In the example illustrated, the stator vane actuation surface 4250 is within the passage 4122 radially intermediate the stator vane axis 4131 and the shaft 4102. In the example illustrated, the stator vane actuation surface 4250 comprises a portion of a leading surface of the rotor block 4246.

[00169] In the example illustrated, the rotor vane pivoting mechanism 4190 comprises a rotor vane actuation surface 4260 fixed relative to the casing 4108. The leading face 4146 of the rotor vane 4140 contacts the rotor vane actuation surface 4260 during rotation of the shaft 4102 for urging the rotor vane 4140 from the closed position to the open position. In the example illustrated, the rotor vane actuation surface 4260 is within the passage 4122 radially intermediate the rotor vane axis 4141 and the casing 4108. In the example illustrated, the rotor vane actuation surface 4260 comprises a portion of a trailing surface of the stator block 4236.

[00170] In the example illustrated, after the rotor vane 4140 passes the stator vane 4130 during rotation of the shaft 4102, flow of fluid urges each of the rotor and stator vanes 4130, 4140 from respective open positions back to respective closed positions.

[00171 ] Referring to Figures 22 to 22B, an example of another rotor vane 5140 and rotor block 5246 is illustrated. The rotor vane 5140 has similarities to the rotor vane 4140, and like features are identified by like reference characters, incremented by 1000. The rotor block 5246 has similarities to the rotor block 4246, and like features are identified by like reference characters, incremented by 1000.

[00172] In the example illustrated, the rotor vane 5140 has a rotor vane height bounded by a rotor vane root edge 5142 and an opposed rotor vane tip edge 5144. In the example illustrated, the rotor vane root edge 5142 includes an inboard portion 5270 axially intermediate spaced apart outboard portions 5272 of the root edge 5142. In the example illustrated, the inboard portion 5270 is recessed toward the rotor vane tip edge 5144 relative to the outboard portions 5272 to provide a radial clearance 5274 between the inboard portion 5270 and a shaft of the motor. This may help wash away particles that may accumulate adjacent the rotor vane root edge 5142 and the rotor block 5246, which may help improve operational efficiency of the motor and reduce the likelihood of the motor jamming due to a buildup of particles.

[00173] In some examples, the motor may include a stator vane having a recessed inboard portion like the inboard portion 5270 of the rotor vane 5140.

[00174] Referring to Figures 23A and 23B, an example of another stator vane 6130 and stator block 6236 is illustrated. The stator vane 6130 has similarities to the stator vane 4130, and like features are identified by like reference characters, incremented by 2000. The stator block 6236 has similarities to the stator block 4236, and like features are identified by like reference characters, incremented by 2000. [00175] In the example illustrated, the stator block 6236 can be fixed relative to the casing via a plurality of stator block bolts passing radially through the stator block 6236 and anchored in the motor casing.

[00176] In the example illustrated, the stator vane 6130 is pivotally supported by the stator block 6236 for pivoting about the stator vane axis 6131 . The stator vane 6130 includes outboard pins 6133a (one of which is shown in Figure 23A) extending outwardly from axial endfaces of the stator vane 6130 along the stator vane axis 6131 . The outboard pins 6133a are received in stator vane apertures 61 13a (one of which is shown in Figure 23A) in axially spaced apart outboard end walls 6237a of the stator block 6236.

[00177] In the example illustrated, the stator vane 6130 further includes at least one inboard pin 6133b (shown in phantom lines in Figure 23B) extending along the stator vane axis 6131 across a recess of the stator vane 6130. The inboard pin 6133b is received in a stator vane aperture in an inboard wall 6237b axially intermediate the outboard end walls 6237a. This can provide an increased number of anchor points for the stator vane 6130, can facilitate use of smaller pins, and can provide clearance for other components of the motor. This can also facilitate use of vanes having an increased length, and can increase the locking torque capacity and torque output and reduce the speed of the motor for a given flow rate and pressure. In some examples, the outboard pins 6133a and the inboard pin 6133b are of integral, unitary one-piece construction. In some examples, the outboard pins 6133a and the inboard pin 6133b comprise a unitary rod extending axially through an entirety of the stator vane 6140.

[00178] Referring to Figure 24, an example of a rotary motor assembly 7000 is shown. The motor assembly 7000 includes a rotary first motor 7100 and a rotary second motor 7600 stacked in series, with the second motor 7600 downstream of the first motor 7100. Each of the first and second motors 7100, 7600 has similarities to the motor 100, and like features are identified by like reference characters, incremented by 7000 and 7500, respectively.

[00179] In the example illustrated, the first and second motors 7100, 7600 are circumferentially offset from one another, such that when the rotor and stator vanes of one of the first and second motors 7100, 7600 are in respective open positions (i.e. the rotor vanes are moving past the stator vanes), the rotor and stator vanes of the other one of the first and second motors 7100, 7600 are in respective closed positions and generating torque on the shaft to rotate the shaft in the power direction (and move the open rotor vanes circumferentially past the open stator vanes so that those rotor and stator vanes can pivot to respective closed positions).

[00180] In the example illustrated, the first motor 7100 includes a housing 7106 having a cylindrical casing 7108 (shown in phantom lines in Figure 24) extending along a drive axis 71 10 between axially spaced apart upstream and downstream end caps 71 12, 71 14. In the example illustrated, the first motor 7100 includes a shaft 7102 rotatably mounted within the housing 7106 and rotatable about the drive axis 71 10. In the example illustrated, the shaft 7102 of the first motor 7100 is rotatably supported by a first set of plain bearing assemblies 71 16 (Figure 25) mounted in the housing 7106.

[00181 ] Referring to Figure 25, in the example illustrated, the upstream end cap 71 12 (Figure 24) includes an upstream stator disc 71 12a and an upstream rotor disc 71 12b, and the downstream end cap 71 14 (Figure 24) includes a downstream stator disc 71 14a and a downstream rotor disc 71 14b. At least one inlet 7124 extends through the upstream end cap 71 12 for conducting fluid into an annular passage 7122 (Figure 24) within the housing 7106 of the first motor 7100. In the example illustrated, the inlet 7124 extends through and is fixed relative to the upstream stator disc 71 12a. At least one outlet 7126 extends through the downstream end cap 71 14 for evacuating fluid from the annular passage 7122 (Figure 24) of the first motor 7100. In the example illustrated, the outlet 7126 extends through and is fixed relative to the downstream stator disc 71 14a. [00182] Referring to Figure 26, in the example illustrated, the first motor 7100 includes a stator vane 7130 and a rotor vane 7140, each pivotable about a respective vane axis 7131 , 7141 between respective open and closed positions. When in respective closed positions, the stator and rotor vanes 7130, 7140 separate the passage 7122 into a circumferentially expanding chamber 7150 in fluid communication with the inlet 7124 for receiving pressurized fluid, and a circumferentially collapsing chamber 7160 in fluid communication with the outlet 7126 for evacuating fluid.

[00183] Referring again to Figure 24, in the example illustrated, the second motor 7600 includes a housing 7606 having a cylindrical casing 7608 (shown in phantom lines in Figure 24) extending along the drive axis 71 10 between axially spaced apart upstream and downstream end caps 7612, 7614. In the example illustrated, the casing 7108 of the first motor 7100 and the casing 7608 of the second motor 7600 are of integral, unitary one-piece construction.

[00184] In the example illustrated, the second motor 7600 includes a shaft 7602 rotatably mounted within the housing 7606 of the second motor 7600 and rotatable about the drive axis 71 10. In the example illustrated, the shaft 7602 of the second motor 7600 is rotatably supported by a second set of plain bearing assemblies 7616 (Figure 25) mounted in the housing 7606. In the example illustrated, the shaft 7102 of the first motor 7100 and the shaft 7602 of the second motor 7600 are of integral, unitary one-piece construction.

[00185] In the example illustrated, at least one inlet 7624 extends through the upstream end cap 7612 of the second motor 7600 for conducting fluid into an annular passage 7622 within the housing 7606 of the second motor 7600. At least one outlet 7626 extends through the downstream end cap 7614 of the second motor 7600 for evacuating fluid from the annular passage 7622.

[00186] Referring to Figure 27, in the example illustrated, the second motor 7600 includes a stator vane 7630 and a rotor vane 7640, each pivotable about a respective vane axis 7631 , 7641 between respective open and closed positions. When in respective closed positions, the stator and rotor vanes 7630, 7640 separate the passage 7622 into a circumferentially expanding chamber 7650 in fluid communication with the inlet 7624 for receiving pressurized fluid, and a circumferentially collapsing chamber 7660 in fluid communication with the outlet 7626 for evacuating fluid.

[00187] Referring to Figures 26 and 27, in the example illustrated, the stator vane axis 7131 of the first motor 7100 is collinear with the stator vane axis 7631 of the second motor 7600, and the rotor vane axis 7141 of the first motor 7100 and the rotor vane axis 7641 of the second motor 7600 are spaced circumferentially apart about the drive axis 71 10. This can facilitate continuous torque output by providing a stacked motor configuration in which at any given angular position of the unitary shafts 7102, 7602, at least one of the first and second motors 7100, 7600 can have rotor and stator vanes in respective closed positions for generating torque on the unitary shafts 7102, 7602. In the example illustrated, the rotor vane axis 7141 of the first motor 7100 and the rotor vane axis 7641 of the second motor 7600 are spaced equally apart about the drive axis 71 10 (by 180 degrees in the example illustrated).

[00188] Referring to Figure 25, in the example illustrated, the upstream end cap 7612 (Figure 24) of the second motor 7600 includes an upstream stator disc 7612a and an upstream rotor disc 7612b, and the downstream end cap 7614 (Figure 24) of the second motor 7600 includes a downstream stator disc 7614a and a downstream rotor disc 7614b. In the example illustrated, the inlet 7624 extends through and is fixed relative to the upstream stator disc 7612a. In the example illustrated, the outlet 7626 extends through and is fixed relative to the downstream stator disc 7614a. In the example illustrated, the downstream stator disc 71 14a of the first motor 7100 and the upstream stator disc 7612a are of integral, unitary one-piece construction.

[00189] Referring to Figure 24, in the example illustrated, fluid evacuated from the annular passage 7122 of the first motor 7100 is conducted into the annular passage 7622 of the second motor 7600. Referring to Figure 25, in the example illustrated, an inter-motor duct 7012 extends axially through the unitary stator discs 71 14a, 7612a between the outlet 7126 of the first motor 7100 and the inlet 7624 of the second motor 7600 for conducting fluid evacuated from the collapsing chamber 7160 of the first motor into the expanding chamber 7650 of the second motor 7600. [00190] In the example illustrated, the inter-motor duct 7012 is radially intermediate outer surfaces of the unitary stator discs 71 14a, 7612a and inner surfaces of the unitary casings 7108, 7608. In the example illustrated, the outlet 7126 of the first motor 7100 and the inlet 7124 of the second motor 7600 are circumferentially offset from one another and disposed on circumferentially opposite sides of the stator vane axes 7131 , 7631 , and the inter-motor duct 7012 extends helically about the drive axis 71 10 therebetween.

[00191 ] Referring to Figures 28 and 29, an example of a rotary motor assembly 8000 is shown. The rotary motor assembly 8000 is similar to the rotary motor assembly 7000, and like features are identified by like reference characters, incremented by 1000.

[00192] In the example illustrated, the motor assembly 8000 includes a first motor 8100 and a second motor 8600 stacked in series. The first motor 8100 includes a housing 8106 a cylindrical casing 8108 (shown in phantom lines in Figure 28) extending along a drive axis 81 10 between axially spaced apart upstream and downstream end caps 81 12, 81 14. A shaft 8102 is rotatably mounted within the housing 8106 and rotatable about the drive axis 81 10.

[00193] Referring to Figure 29, in the example illustrated, the first motor 8100 includes a stator vane 8130 and a rotor vane 8140, each pivotable about a respective vane axis 8131 , 8141 (shown in phantom lines in Figure 29) between respective open and closed positions. When in respective closed positions, the stator and rotor vanes 8130, 8140 separate an annular passage 8122 (Figure 28) within the housing 8106 into a circumferentially expanding chamber 8150 in fluid communication with an inlet 8124 for receiving pressurized fluid, and a circumferentially collapsing chamber 8160 in fluid communication with an outlet 8126 for evacuating fluid. [00194] The inventors have discovered that increasing the length of the stator and rotor vanes 8130, 8140 results in a corresponding increase in torque output, but also increased deflection of the stator and rotor vanes 8130, 8140 and stress on the pins pivotally supporting the vanes 8130, 8140. To help avoid these problems, but still achieve a desired torque output, a vane support 8250 can be provided in the passage 8122 for providing an axially intermediate support to the stator and rotor vanes 8130, 8140.

[00195] Referring to Figure 28, in the example illustrated, the vane support 8250 separates the passage 8122 into a passage upstream portion 8122a and a passage downstream portion 8122b axially downstream of the passage upstream portion 8122a. In the example illustrated, the stator vane 8130 includes a stator vane upstream portion 8230a extending axially across the passage upstream portion 8122a. The stator vane upstream portion 8230a extends axially between an upstream end pivotally supported by an upstream stator disc 81 12a of the upstream end cap 81 12, and a downstream end pivotally supported by a first support stator disc 8251 a of the vane support 8250. The stator vane 8130 further includes a stator vane downstream portion 8230b extending axially across the passage downstream portion 8122b. The stator vane downstream portion 8230b extends axially between an upstream end pivotally supported by a second support stator disc 8251 b of the vane support 8250 and a downstream end pivotally supported by a downstream stator disc 81 14a of the downstream end cap 81 14. In the example illustrated, the first and second support stator discs 8251 a, 8251 b are of integral, unitary one-piece construction.

[00196] Referring to Figure 29, in the example illustrated, the rotor vane 8140 includes a rotor vane upstream portion 8240a extending axially across the passage upstream portion 8122a. The rotor vane upstream portion 8240a extends axially between an upstream end pivotally supported by an upstream rotor disc 81 12b of the upstream end cap 81 12, and a downstream end pivotally supported by a first support rotor disc 8252a of the vane support 8250. The rotor vane 8140 further includes a rotor vane downstream portion 8240b extending axially across the passage downstream portion 8122b. The rotor vane downstream portion 8240b extends axially between an upstream end pivotally supported by a second support rotor disc 8252b of the vane support 8250 and a downstream end pivotally supported by a downstream rotor disc 81 14b of the downstream end cap 81 14.

[00197] In the example illustrated, the expanding chamber 8150 comprises an expanding chamber duct 8256 extending axially through the vane support 8250 for providing fluid communication between the passage upstream portion 8122a and the passage downstream portion 8122b. In the example illustrated, the expanding chamber duct 8256 extends generally parallel to the drive axis 81 10. In the example illustrated, the inlet 8124 has an inlet circumferential extent between an inlet leading edge 8125a spaced circumferentially apart from the stator vane axis 8131 in a power direction 8104, and an inlet trailing edge 8125b circumferentially intermediate the inlet leading edge 8125a and the stator vane axis 8131 . In the example illustrated, the expanding chamber duct 8256 is circumferentially intermediate the inlet leading edge 8125a and the inlet trailing edge 8125b.

[00198] Referring to Figure 28, in the example illustrated, the collapsing chamber 8160 comprises a collapsing chamber duct 8258 extending axially through the vane support 8250 for providing fluid communication between the passage upstream portion 8122a and the passage downstream portion 8122b. In the example illustrated, the collapsing chamber duct 8258 extends generally parallel to the drive axis 81 10. In the example illustrated, the outlet 8126 has an outlet circumferential extent between an outlet trailing edge 8127a spaced circumferentially apart from the stator vane axis 8131 (Figure 29) in a reverse direction opposite the power direction 8104, and an outlet leading edge 8127b circumferentially intermediate the outlet trailing edge 8127a and the stator vane axis 8131 (Figure 29). In the example illustrated, the collapsing chamber duct 8258 is circumferentially intermediate the outlet trailing edge 8127a and the outlet leading edge 8127b. [00199] In the example illustrated, the second motor 8600 includes a vane support 8750 similar to the vane support 8250 of the first motor 8100.

[00200] Referring to Figures 30 and 31 , an example rotary pump assembly 9000 is illustrated. The pump assembly 9000 has similarities to the motor assembly 7000 and like features are identified by like reference characters, incremented by 2000. In the example illustrated, the pump assembly 9000 includes a rotary first pump 9100 and a rotary second pump 9600 stacked in series.

[00201 ] In the example illustrated, the first pump 9100 includes a housing 9106 having a cylindrical casing 9108 extending along a drive axis 91 10 between axially spaced apart upstream and downstream end caps 91 12, 91 14 (Figure 32). Referring to Figure 32, a shaft 9102 is rotatably mounted within the housing 9106 and rotatable relative to the casing 9108 about the drive axis 91 10.

[00202] Referring to Figure 33, in the example illustrated, the first pump 9100 includes an annular passage 9122 within the housing 9106. The annular passage 9122 is radially intermediate the shaft 9102 and the casing 9108 and bounded axially by the end caps 91 12, 91 14. [00203] In the example illustrated, the first pump 9100 includes an inlet 9124 in the housing 9106 for conducting fluid into the annular passage 9122, and an outlet 9126 in the housing 9106 for evacuating fluid from the annular passage 9122. In the example illustrated, the inlet 9124 and the outlet 9126 are spaced circumferentially apart, and each extends radially through and is fixed relative to the casing 9108.

[00204] In the example illustrated, the first pump 9100 includes a stator vane 9130 extending axially across the passage 9122. The stator vane 9130 is pivotable about a stator vane axis 9131 fixed relative to the casing 9108 between a stator vane closed position for inhibiting circumferential fluid flow in the passage 9122 across the stator vane 9130, and a stator vane open position (shown in Figure 33). The inlet 9124 and the outlet 9126 are disposed on circumferentially opposite sides of the stator vane axis 9131 .

[00205] In the example illustrated, the first pump 9100 includes a rotor vane 9140 extending axially across the passage 9122. The rotor vane 9140 is pivotable about a rotor vane axis 9141 fixed relative to the shaft 9102 between a rotor vane closed position for inhibiting circumferential fluid flow in the passage 9122 across the rotor vane 9140, and a rotor vane open position (shown in Figure 33).

[00206] Still referring to Figure 33, when the rotor and stator vanes 9130, 9140 are in respective open positions, the rotor vane 9140 is movable circumferentially past the stator vane 9130 during rotation of the shaft 9102 in the power direction 9104. When in respective closed positions, the stator and rotor vanes 9130, 9140 separate the passage 9122 into a circumferentially expanding chamber and a circumferentially collapsing chamber spaced circumferentially apart from the expanding chamber (see Figure 36 showing stator and rotor vanes of the second pump 9600 in respective closed positions). The expanding chamber is in fluid communication with the inlet 9124 for drawing fluid into the expanding chamber during rotation of the shaft 9102 in the power direction 9104. The collapsing chamber is in fluid communication with the outlet 9126 for discharging pressurized fluid from the collapsing chamber during rotation of the shaft 9102 in the power direction 9104. [00207] In some examples, the inlet 9124 can include a one-way fluid check valve for permitting flow of fluid into the expanding chamber through the inlet 9124 and blocking flow of fluid out from the expanding chamber through the inlet 9124. In some examples, the outlet 9126 can include a one-way fluid check valve for permitting flow of fluid out from the collapsing chamber through the outlet 9126 and blocking flow of fluid into the collapsing chamber through the outlet 9126.

[00208] In the example illustrated, the first pump 9100 includes a vane pivoting mechanism for urging the stator and rotor vanes 9130, 9140 to pivot from respective closed positions to respective open positions when the shaft 9102 rotates through at least one predetermined angular position. In some examples, rotation of the shaft and fluid flow dynamics may be sufficient to pivot one or both of the stator and rotor vanes 9130, 9140 from respective open positions back to respective closed positions after the rotor vane 9140 passes the stator vane 9130. Optionally, the vane pivoting mechanism can urge one or both of the stator and rotor vanes 9130, 9140 to pivot from respective open positions toward respective closed positions after the rotor vane 9140 passes the stator vane 9130.

[00209] Referring to Figure 34, in the example illustrated, the vane pivoting mechanism includes a stator vane pivoting mechanism 9180 for pivoting the stator vane 9130 between the stator vane open and closed positions. The stator vane pivoting mechanism 9180 includes a stator vane actuator 9182 and a pair of stator vane first and second crank arms 9184a, 9184b fixed to and extending radially from a stator vane pin 9133 of the stator vane 9130. In the example illustrated, the stator vane actuator 9182 includes a stator vane first cam surface 9188 fixed to rotate with the shaft 9102 for engaging the stator vane first crank arm 9184a to urge the stator vane 9130 toward the stator vane closed position (see Figure 37 showing the stator vane first cam surface of the second pump 9600 in engagement with the stator vane first crank arm of the second pump 9600). The stator vane actuator 9182 further includes a stator vane second cam surface 9189 fixed to rotate with the shaft 9102 for engaging the stator vane second crank arm 9184b to urge the stator vane 9130 toward the stator vane open position (see Figures 33 and 34). [00210] Referring to Figure 35, in the example illustrated, the vane pivoting mechanism further includes a rotor vane pivoting mechanism 9190 for pivoting the rotor vane 9140 between the rotor vane open and closed positions. The rotor vane pivoting mechanism 9190 includes a rotor vane actuator 9192 and a pair of rotor vane first and second crank arms 9194a, 9194b fixed to and extending radially from a rotor vane pin 9143 of the rotor vane 9140. In the example illustrated, the rotor vane actuator 9192 includes a rotor vane first cam surface 9198 fixed relative to the casing 9108 for engaging the rotor vane first crank arm 9194a to urge the rotor vane 9140 toward the rotor vane closed position (see Figure 38 showing the rotor vane first cam surface of the second pump 9600 in engagement with the rotor vane first crank arm of the second pump 9600). The rotor vane actuator 9192 further includes a rotor vane second cam surface 9199 fixed relative to the casing 9108 for engaging the rotor vane second crank arm 9194b to urge the rotor vane 9140 toward the rotor vane open position (see Figures 33 and 35). [0021 1 ] Referring to Figure 32, the second pump 9600 is similar to the first pump 9100, and like features are identified by like reference characters, incremented by 500. In the example illustrated, the second pump 9600 includes a housing 9606 (Figure 30) having a cylindrical casing 9608 extending along the drive axis 91 10 between axially spaced apart upstream and downstream end caps 9612, 9614. In the example illustrated, the second pump 9600 includes a shaft 9602 rotatably mounted within the housing 9606 and rotatable about the drive axis 91 10.

[00212] Referring to Figure 36, in the example illustrated, the second pump 9600 includes a stator vane 9630 and a rotor vane 9640, each pivotable about a respective vane axis 9631 , 9641 between respective open and closed positions. When in respective closed positions, the stator and rotor vanes 9630, 9640 separate the passage 9622 into a circumferentially expanding chamber 9650 in fluid communication with an inlet 9624 for drawing fluid into the expanding chamber 9650, and a circumferentially collapsing chamber 9660 in fluid communication with an outlet 9626 for discharging pressurized fluid from the collapsing chamber 9660. When the rotor and stator vanes 9630, 9640 are in respective open positions, the rotor vane 9640 is movable circumferentially past the stator vane 9630 during rotation of the shaft 9602 in the power direction 9104 (see Figure 33 showing the stator and rotor vanes 9130, 9140 of the first pump 9100 in respective open positions).

[00213] Referring to Figure 30, in the example illustrated, fluid evacuated from the annular passage 9122 of the first pump 9100 is conducted into the annular passage 9622 of the second pump 9600. In the example illustrated, an inter-pump duct 9012 (shown schematically in Figure 30) extends between the outlet 9126 of the first pump 9100 and the inlet 9124 of the second pump 9600 for conducting fluid from the collapsing chamber of the first pump 9100 into the expanding chamber 9650 of the second pump 9600 (see also Figures 33 and 36). In the example illustrated, the inter- pump duct 9012 is external the casings 9108, 9608 of the first and second pumps 9100, 9600.

[00214] In the example illustrated, the second pump 9600 includes a vane pivoting mechanism for urging the stator and rotor vanes 9630, 9640 to pivot from respective closed positions to respective open positions at predetermined angular positions of the shaft 9602. Optionally, the vane pivoting mechanism can urge one or both of the stator and rotor vanes 9630, 9640 to pivot from respective open positions toward respective closed positions.

[00215] Referring to Figure 37, the vane pivoting mechanism of the second pump 9600 includes a stator vane pivoting mechanism 9680 in the housing 9606 having a stator vane actuator 9682 and a pair of stator vane first and second crank arms 9684a, 9684b. The stator vane pivoting mechanism 9680 includes a stator vane first cam surface 9688 for engaging the stator vane first crank arm 9684a to urge the stator vane toward the closed position, and a stator vane second cam surface 9689 for engaging the stator vane second crank arm 9684b to urge the stator vane toward the open position.

[00216] Referring to Figure 38, the vane pivoting mechanism further includes a rotor vane pivoting mechanism 9690 having a rotor vane actuator 9692 and a pair of rotor vane first and second crank arms 9694a, 9694b. In the example illustrated, the rotor vane actuator 9692 includes a rotor vane first cam surface 9698 for engaging the rotor vane first crank arm 9694a to urge the rotor vane 9640 toward the rotor vane closed position, and a rotor vane second cam surface 9699 for engaging the rotor vane second crank arm 9694b to urge the rotor vane 9640 toward the rotor vane open position.