FIELD

[0001] The present invention relates to the field of gerotor mechanisms including gerotor pumps, gerotor compressors, gerotor expanders, gerotor heat pumps and gerotor engines.

BACKGROUND

[0002] In most gerotor mechanism applications, the inner and outer gerotors of a gerotor set are synchronized by direct contact, whereby a powered gerotor directly contacts and drives a non-powered gerotor. However, the friction of the direct contact between the two gerotors produces heat and causes wear of the contacting surfaces, which in turn allows more leakage of fluids or gases past the gerotors. For this reason, direct contact gerotor mechanisms are mainly used to pump fluids that are lubricating in nature, such as engine oil or hydraulic fluid. Therefore, it is known that high

temperature gases or fluids tend to increase the problems of friction and wear of gerotor mechanisms, as these fluids are considered non-lubricating. Also, at high rotational speeds, the heat generated by the friction of direct contact can soften and even melt or weld gerotor materials such as aluminum or steel, causing accelerated wear and, in some cases, destructive failure or seizing of the mechanism.

[0003] For applications that require the pumping of a fluid or gas that has poor lubrication properties, one method used to avoid excessive mechanical friction and wear has been to use an externally meshed set of gears or other alignment mechanism to align the inner and outer gerotors. These externally meshed gears can be bathed in lubricating oil to reduce friction. The inner and outer gerotors are then assembled such that they closely approach each other during rotation but do not make contact, thus avoiding mechanical friction.

[0004] However, using an externally meshed set of gears or other alignment mechanism for alignment of a gerotor pair can result in the following disadvantages: a) this approach requires a number of additional precision parts, which increases complexity and costs; and, b) maintaining precision clearances between inner and outer gerotor surfaces and between casing and gerotor surfaces is made more difficult because of cumulative tolerance stack up effects. It is realized that slight inaccuracies in position or angle in a chain of mechanical linkages can accumulate and even multiply, making it difficult and costly to manufacture and assemble gerotor pairs with the precision clearances necessary for efficient operation. If clearances are increased to compensate for stack-up tolerance effects, then leakage of fluids or gases around the gerotors increases and operating efficiency is decreased.

SUMMARY

[0005] It is an object of the present invention to provide multiply connected gerotor sets with the inner and outer gerotors that obviates or mitigates at least some of the above-presented disadvantages.

[0006] It is desirable to provide multiply connected gerotor sets such that the inner and outer gerotors are synchronized to operate without contact during rotation, (a) with as few additional parts as possible; and (b) in a manner that minimizes tolerance stack-up effects.

[0007] Aspects are provided as improvements to existing art of the design, manufacture and performance of gerotor mechanisms including: a) an improved method of non-contact rotational synchronization of an inner gerotor with an outer gerotor;

and/or b) an improved method of providing sealing and/or providing load bearing for gerotor pairs in gerotor mechanisms. These improvements can result in a number of benefits including: a) the simplification of the manufacture of non-contact synchronized gerotor mechanisms by a reduction in the number and complexity of component parts; b) simpler and improved precision alignment of parts, with reduced tolerance stack up; and/or c) improved sealing of gerotor pairs to reduce leakage from the gerotor displacement volumes. [0008] Present aspects relate to an improved mechanical design of synchronized gerotor pairs that pump, compress or expand a working fluid. The working fluid may be any liquid or gas or other material possessing fluid properties. The improved gerotor design is a compound, co-rotating, synchronized assembly of gerotors, abbreviated here as a "CoRotor".

[0009] A CoRotor can comprise: a) one or more "work gerotor sets" that operate on the working fluid, where the inner and outer gerotors approach each other closely, but do not make mechanical contact; b) one or more "sync gerotor sets" which using direct lubricated or non-lubricated contact between the inner and outer gerotors to transmit mechanical drive and to keep the assembly of gerotor sets synchronized and co-rotating, and, c) one or more mounting members (e.g. central common shaft, "CoRotor bearings", etc.) to provide nominally independent rotation of all rotating components of the work gerotor sets; to transmit forces between work and synch gerotor sets; and to act as a mechanical seal that keeps separate the working fluid of the work gerotor set from the working fluid of the sync gerotor set.

[0010] Since the sync gerotors can be of similar shape to the work gerotors and are mounted on the same fixed rotation axes, precision tolerances and minimum clearances can be maintained with much greater ease, fewer precision parts and lower cost than the alternative of a set of synchronizing gears. The axial length of the sync gerotor along the length of the common axes can be chosen according to the drive forces to be born, with a longer axial length required for a greater drive force.

[0011] According to one aspect, a CoRotor Brayton cycle engine can be constructed comprising, by mounting on a common axes: a) at least one sync gerotor pair; with b) at least one compressor work gerotor pair; c) at least one expander work gerotor pair; and, d) mounting members. A combustor and an optional recuperator are added to create an open Brayton cycle engine. An optional cooling heat exchanger is added to create a closed Brayton cycle engine. [0012] A further aspect provided is a gerotor mechanism for moving a work fluid between an input fluid port and an output fluid port comprising: a synchronization gerotor set having an inner synch gerotor positioned on a first fixed axis and an outer synch gerotor positioned on a second fixed axis offset from the first fixed axis, such that rotation about the respective fixed axis of one of the inner synch gerotor or the outer synch gerotor through contact there between drives rotation of the other of the inner synch gerotor or the outer synch gerotor about the other respective fixed axis; a work gerotor set having an inner work gerotor positioned on the first fixed axis and an outer work gerotor positioned on the second fixed axis, the work gerotor set for moving the work fluid during rotation of the inner work gerotor and the outer work gerotor about their respective fixed axis without contact between an outer surface of the inner work gerotor and an outer surface of the outer work gerotor; an inner mounting member connecting the inner synch gerotor with the inner work gerotor such that rotation of the inner synch gerotor about the first fixed axis drives the rotation of the inner work gerotor about the first fixed axis, the inner mounting member and the inner synch gerotor and the inner work gerotor part of an inner gerotor assembly; and an outer mounting member connecting the outer synch gerotor with the outer work gerotor such that rotation of the outer synch gerotor about the second fixed axis drives the rotation of the outer work gerotor about the second fixed axis, the outer mounting member and the outer synch gerotor and the outer work gerotor part of an outer gerotor assembly.

[0013] A technical advantage of a CoRotor Brayton cycle engine compared to the current art is that precision alignment of rotating component parts and the maintenance of precision clearances can be fundamentally simpler and less costly to implement when all such rotating parts are mounted on common axes. In particular, the current invention can inhibit the cumulative tolerance stack-up problems of other more complex gerotor synchronization mechanisms, such as the use of an externally meshed set of gears or alignment systems for inner and outer gerotor synchronization.

[0014] Another technical advantage of a CoRotor Brayton cycle engine compared to the current art is that the resulting implementation can be very compact in all dimensions and uses less materials, resulting in combustion engines with greater volume energy density and mass energy density; which are particularly important for mobile engine applications and even more important for aerospace applications.

[0015] Another technical advantage of a CoRotor Brayton cycle engine compared to the current art is that few parts can be required and those parts are of relatively simple and less costly construction.

[0016] Another technical advantage of a CoRotor Brayton cycle engine compared to the current art is that heat can be removed from the shaft and bearings by the lubricating fluid that is pumped through the sync gerotor set or sets, which can reduce thermal expansion of these parts, reduces thermally induced wear, and extends the working life of these parts.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] For a more complete understanding of the present invention, the needs satisfied thereby, and the features and advantages thereof, reference now is made to the following descriptions taken in connection with the accompanying drawings in which:

[0018] Fig. 1a depicts a section view of a gerotor set contained with an

encasement;

[0019] Fig. 1 b is a side view along section A-A of the gerotor set of Fig. 1 a;

[0020] Fig. 1c is an example side view of a stacked gerotor mechanism using multiple gerotor sets of the gerotor set of Fig 1a;

[0021] Fig. 1d is an alternative embodiment of the stacked gerotor mechanism of Fig 1c;

[0022] Fig. 1e is an alternative embodiment of the stacked gerotor mechanism of Fig 1c; [0023] Fig. 2 depicts an exploded isometric view of a cantilevered gerotor mechanism;

[0024] Fig. 3 depicts a schematic sectional view of a gerotor mechanism according as an alternative embodiment of the stacked gerotor mechanism of Fig 1 c;

[0025] Fig. 4 depicts a schematic cross-section of the stacked gerotor

mechanism of Fig. 3 along section line 4-4;

[0026] Figs. 5A and 5B depict images of a gerotor set as an alternative

embodiment of the gerotor set of Fig. a showing ports;

[0027] Fig. 6 depicts a sectional view of a Brayton cycle engine using an alternative embodiment of the stacked gerotor mechanism of Fig 1c;

[0028] Fig. 7 depicts a sectional view of a Brayton cycle engine using a further alternative embodiment of the stacked gerotor mechanism of Fig 1c;

[0029] Fig. 8 depicts a block diagram of a Brayton cycle engine using a further alternative embodiment of the stacked gerotor mechanism of Fig 1c;

[0030] Fig. 9a is a further alternative embodiment of the gerotor set of Fig. 1a;

[0031] Fig. 9b is a further alternative embodiment of the gerotor set of Fig. 1a;

[0032] Fig. 10a is an alternative embodiment of the stacked gerotor mechanism of Fig. 3; and

[0033] Fig. 10b is a further alternative embodiment of the stacked gerotor mechanism of Fig. 3.

DETAILED DESCRIPTION OF THE INVENTION

[0034] Inner and outer gerotors of a gerotor pair rotate in the same rotational direction, but at different speeds, with the outer gerotor rotating at a slightly slower rate than the inner gerotor. For each full revolution of an inner gerotor with N teeth, the outer gerotor turns only 1 - 1/(N+1) revolutions. For example, if N is 5 (the inner gerotor has 5 teeth) then the outer gerotor has 6 teeth, and turns only 1 minus1/6, or 5/6 of a revolution for every full revolution of the inner gerotor. Because of this difference in rotational rates, each external tooth advances (or regresses, depending upon the direction of rotation) with each rotation to mesh with the sequential internal tooth position, so that each tooth should fit in all complementary tooth positions as precisely as possible while avoiding contact that would result in interference or wear. What is needed is a synchronization mechanism for multiple paired gerotor sets that maintains minimum achievable clearances for those work gerotor sets that are used to work non- lubricating fluids, in order to minimize leakage of fluids or gases as they are pumped, compressed or expanded, while at the same time inhibit wear and heat generation due to sliding contact friction between the inner and outer work gerotors. It is recognised that the synch gerotor set(s) bear the mechanical load of the gerotor mechanism due to work performed on the work fluid, on behalf of the work gerotor set(s), as contact is experienced between the lobes of the synch gerotors while contact is inhibited between the lobes of the work gerotors. Gerotors are different from other traditional gears systems in that traditional gear systems can have two sets of externally meshed teeth (i.e. both sets of teeth on each gear of a two gear system have teeth that project outwardly as formed on an outer surface of a cylinder of cone). Also, gerotor use complimentary when calculated using mathematical formulas (e.g. cycloid) such that inner and outer gerotors mesh at the nominal seal lines 104 , 110 creating N+1 nominally sealed displacement volume 1 4. Conversely, gerotors include internally meshed teeth (i.e. one set of teeth of a two gear system has teeth that project inwardly as formed on an inner surface of a cylinder of cone while the other set of teeth projects outwardly as formed on an outer surface of a cylinder of cone).

[0035] Further, the sync gerotor sets 305 (see Figure 1c) can pump (i.e. circulate) cooling air or other cooling fluid through intake and exhaust ports/channels (not shown) formed in the body of the gerotors 102,103 and adjacent housing 101 , in order to remove heat generated by the contact friction of the gerotors 102,103 by passing the circulated cooling fluid through a heat exchanger, thus using the pumping/circulation action provided by rotation of the gerotor set to force the cooling fluid through the heat exchanger in a closed loop fluid circuit, avoiding excessive wear or damage that could be caused by any material temperature rise.

[0036] With reference to Fig. 1 a, there is shown in sectional view a generic gerotor set 1 12 which comprises an inner gerotor 102 having N nominally circularly shaped outwardly extending lobes 1 1 1 (e.g. teeth) and an eccentrically disposed outer gerotor 103 having N + 1 inwardly extending complementary nominally circularly shaped lobes 109 (e.g. teeth). The generic gerotor set 1 12 is concentrically disposed within an encasement 101 (e.g. housing). The N + 1 displacement chambers 107 are formed between N nominal line seals 1 10 provided by the mesh of the outwardly 111 and inwardly 109 extending lobes and an additional nominal line seal 104 between one inwardly extending lobe 09 and a juxtaposed one of N grooves 105 of the inner gerotor 102 nearest the "in-mesh" position of the gerotor set 1 2. The inner gerotor 102 can have a hole 100 for mounting on a shaft, for example. The line seals 1 10, 104 are defined as lines of contact (or closest approach in the case of non-contact for work gerotor sets 304) between the lobes 109,1 11 as a line or curve along which two tooth (i.e. lobe) surfaces are tangent to each other.

[0037] The name gerotor is derived from "Mathematically Generated Rotor".

Each gerotor set 1 12 consists of the inner 102 and outer 103 gerotors, such that the inner gerotor has N shaped outwardly extending lobes 111 (e.g. external teeth) and the outer gerotor has N+1 complementary inwardly extending lobes 109 (e.g. internal teeth) that mesh with one another (i.e. outwardly 1 1 1 with inwardly 109 extending lobes) as the inner gerotor 102 rotates about the first fixed axis 106 and the outer gerotor 103 rotates about the second fixed axis 1 13. The inner gerotor 102 is located off-center and both gerotors 102,103 rotate such that the external inner gerotor 102 teeth mesh with the internal outer gerotor 103 teeth, leaving a series of displacement volume gaps between the inner 102 and outer 103 gerotors.

[0038] The geometry of the two gerotors 102, 103 partitions the volume

(containing fluid - e.g. incompressible hydraulic fluid or compressible fluid) between them into N separate dynamically changing volumes 114. During the assembly's rotation cycle, each of these volumes changes continuously, so any given volume increases, and then decreases. An increase in volume creates a vacuum. This vacuum creates suction, and therefore the fluid intake (see Figure 5a, b) is physically placed at this part of the cycle using an input port (not shown) for providing fluid into the volume 114. Compression occurs as a volume decreases. Fluids can be pumped (i.e. fluid output) during this compression period, or, if they are gaseous fluids, they can be compressed as output though output ports (not shown) for providing fluid output out of the volume 114. The mechanical work required for pumping or compressing a fluid or gas is introduced by way of a shaft 120,122 (see Figure 1 c) or other torqueing mechanism connected to either the inner 102 or the outer 103 gerotor. It is recognised that the input and output ports can be positioned in the bodies of the inner 102 and outer 103 gerotors (e.g. at the tips of the lobes 109, 1 11 ) so as to provide for fluid ingress and egress with respect to the volume 1 14 during the expansion and

compression cycles of the gerotor set 1 12 due to rotation of the inner gerotor 102 within the outer gerotor 103.

[0039] When a gerotor pair is rotated counterclockwise, gases taken in at an inlet port are delivered compressed to an outlet port. When a gerotor pair compresses gases, work energy are provided by way of a connected shaft or other mounting member 120,122. When a gerotor pair is rotated clockwise, gases taken in at an inlet port are delivered expanded to an outlet port. When pressurized gases are expanded by a gerotor pair mechanical work can be extracted by way of a connected shaft other mounting member 120,122.

[0040] Gerotor pumps consisting of a stacked gerotor configuration can be used extensively in mechanical systems because they are simple, efficient, compact, robust and inexpensive to mass-produce. Common uses of gerotor pumps include: oil pumps; fuel pumps; hydraulic motors; and power steering systems. Currently, hundreds of thousands of these gerotor pumps are manufactured each day around the world, with the automotive industry being the biggest user. [0041] Referring to Figure 1 b, shown is a side view along section line A-A of the generic gerotor set 112 of Figure 1 a. The inner gerotor 102 has a first fixed axis 106, such that during operation of the gerotor set 112 the inner gerotor 102 rotates about the first fixed axis 106. Similarly, the outer gerotor 103 has a second fixed axis 13, such that during operation of the gerotor set 112 the outer gerotor 103 rotates about the second fixed axis 1 3. As is shown, the first axis 106 is offset (e.g. the axes 106,113 are non-intersecting lines that lie on the same plane such that they have an equal distance - offset distance 1 19 between them) from the second axis 113 in order to account for clearance of the lobes 109,1 1 1 from one another as the inner gerotor 102 rotates within the outer gerotor 103.

[0042] As shown in Figure 1c, the generic gerotor set 1 12 can be embodied in a stacked gerotor set configuration, including one or more work gerotor sets 304 and one or more synch gerotor sets 305, such that adjacent pairs of gerotor sets 304, 305 are mechanically coupled to one another within a common housing 01 , as further described below. Preferably at least one synch gerotor set 305 is coupled to at least two work gerotor sets 304 in the stacked gerotor set configuration, thereby providing for an inner gerotor assembly 130 having at least three inner gerotors 102 fixedly coupled to one another and an outer gerotor assembly 132 having at least three outer gerotors 102 fixedly coupled to one another. It is also recognized that at least one work gerotor set 304 can be coupled to at least two synch gerotor sets 305 in the stacked gerotor set configuration, thereby providing for the inner gerotor assembly 130 having at least three inner gerotors 102 fixedly coupled to one another and the outer gerotor assembly 132 having at least three outer gerotors 102 fixedly coupled to one another.

[0043] Shown is the stacked gerotor set configuration such that the inner gerotors

102 of the gerotor sets 304, 305 are connected to one another by inner mounting member(s) 120 positioned between the adjacent inner gerotors 102. The series of inner gerotors 102 and inner mounting member(s) 120 are referred to as the inner gerotor assembly 30. One example of the inner mounting member(s) 120 is a common shaft 120 extending between (and optionally through) the adjacent inner gerotors 102 of the gerotor sets 304, 305, however it is recognized that inner mounting member(s) 120 other than as shown can be used, as desired. The inner mounting member(s) 120 provide(s) the first fixed axis 106 that is the same for all of the inner gerotors 102 of the stacked gerotor set configuration, such that rotation of each of the inner gerotors 102 is around the same first fixed axis 106 at the same angular speed. In other words the inner gerotor assembly 130 rotates as a whole about the first fixed axis 106. The inner mounting member(s) 120 positioned between the housing 101 and the inner gerotors 102 directly adjacent to the housing 101 can be supported on one or more bearings 124 (e.g. positioned between the mounting member(s) 120 and the housing 101 ).

[0044] Further, the outer gerotors 103 of the gerotor sets 304, 305 are connected to one another by outer mounting member(s) 122 positioned between the adjacent outer gerotors 103. The series of outer gerotors 103 and outer mounting member(s) 122 are referred to as the outer gerotor assembly 132. The outer mounting member(s) 122 can also provide for sealing of the displacement chambers 107 of adjacent gerotor sets 1 12 of the stacked gerotor configuration, in order to inhibit mixing of fluids between adjacent gerotor sets 1 12 that operate using different fluids (e.g. inhibit hydraulic fluid contained in the displacement chambers 07 of a synch gerotor set 305 becoming mixed or otherwise contaminated with compressible gas contained in the displacement chambers 107 of the work gerotor set 304, or inhibit compressible gas contained in the

displacement chambers 107 of a work gerotor set 304 becoming mixed or otherwise contaminated with hydraulic fluid contained in the displacement chambers 107 of the synch gerotor set 305).

[0045] One example of the outer mounting member(s) 122 is a corotor bearing 308 (see Figure 3) extending between (and optionally through) the adjacent outer gerotors 103 of the gerotor sets 304, 305, however it is recognized that outer mounting member(s) 122 other than as shown can be used, as desired. The outer mounting member(s) 122 provide(s) the second fixed axis 1 13 that is the same for all of the outer gerotors 103 of the stacked gerotor set configuration, such that rotation of each of the outer gerotors 103 is around the same second fixed axis 113 at the same angular speed. In other words the outer gerotor assembly 132 rotates as a whole about the second fixed axis 1 13. The outer mounting member(s) 122 positioned between the housing 101 and the outer gerotors 103 directly adjacent to the housing 101 can be supported on one or more bearings 126, for example positioned between the housing 101 and the mounting member(s) 22 and/or positioned between the mounting member(s) 120 and the mounting member(s) 122 (e.g. bearings 126 are mounted on shaft 120 and shaft 120 is mounted on the housing by bearings 124).

[0046] In the stacked gerotor configuration, referring to Figures 1a,b,c, it is recognized that the nominal line seals 1 10, 104 between the lobes 109,1 1 1 can be formed due to line contact (with or without an intermediate hydraulic lubricating film 17 - e.g. oil, water or other considered incompressible fluid) between an outer surface 115 of the outer gerotor 103 and an outer surface 1 6 of the inner gerotor 02, at the position of the line seal 1 1 1 ,104, as the inwardly extending lobes 109 slide across the outwardly extending lobes 1 1 1 during rotation of the inner 102 and outer 103 gerotors in operation of the gerotor set 1 12 (see Figures 9a, b). Line contact between the surfaces 1 15,1 16 without an intervening lubricating film 17 is defined as direct contact and line contact between the surfaces 115,116 with an intervening lubricating film 7 is defined as indirect contact, such that rotation of one of the gerotors 102,103 of the gerotor set 1 12 drives the rotation of the other of the gerotors 102,103 of the gerotor set 1 12 due to contact between the respective lobes 109,1 11 of the gerotors 102, 103 of the gerotor set 1 12. A synch gerotor set 306 can be defined as a generic gerotor set 112 that is configured to use line contact to have rotation of one of the gerotors 102,103 of the gerotor set drive the rotation of the other of the gerotors 02, 03 of the same gerotor set (i.e. forces exerted along the nominal line seals 11 1 , 104 by the lobes 109, 1 1 1 against respective adjacent lobes 1 1 1 , 109). The contact surfaces 115, 1 6 of the gerotor sets 304, 305 can be formed of materials that are hard and will resist wear from contact friction and these surfaces 1 15,1 16 can be lubricated, made of materials such as but not limited to metal and/or ceramic.

[0047] One example of line contact is where rotation of the inner gerotor 102 of the synch gerotor set 305 can be provided by rotation of a shaft 120 (e.g. by a motor - not shown) upon which the inner gerotor 102 is mounted, such that contact between the lobes 1 1 1 of the rotating inner gerotor 102 against the lobes 109 of the outer gerotor 103 causes rotational speed of the outer gerotor 103 to be relative to the rotation of the inner rotor 103 according to a relative rotation ratio (e.g. inner gerotors 102 rotate at one speed while the outer gerotors 103 rotate at a rate that is slower than the rotational speed of the inner gerotors 102 by a factor of 1/(N+1)). This is an example of the inner gerotor 102 of the synch gerotor set 305 being the drive gerotor and the outer gerotor 103 of the synch gerotor set 305 being the driven gerotor. Alternatively, rotation of the outer gerotor 103 of the synch gerotor set 305 can be provided by rotation of a shaft 122 (e.g. by a motor - not shown) to which the outer gerotor 103 is attached, such that contact between the lobes 109 of the rotating outer gerotor 103 against the lobes 111 of the inner gerotor 102 causes rotational speed of the inner gerotor 102 to be related to the rotation of the outer rotor 102 according to the ratio. This is an example of the outer gerotor 103 of the synch gerotor set 305 being the drive gerotor and the inner gerotor 102 of the synch gerotor set 305 being the driven gerotor. In the examples of the synch gerotor set 305, it is recognized that preferably there is provided a hydraulic lubrication film 117 (e.g. oil film) between surfaces 115,116 of the lobes 109,1 1 to inhibit direct surface 115 to surface 116 contact to help mitigate undesirable wear of the surfaces 115,116 as well as heat generation due to sliding friction between the lobes 109,111.

[0048] It is recognized that the nominal line seals 110, 104 can also be formed in the case for a work gerotor set 304 where there is no actual line contact, such that the outer surface 115 of the outer gerotor 103 and the outer surface 116 of the inner gerotor 102, at the position of the line seal 111 , 104, are maintained a set distance 118 from one another as the inwardly extending lobes 109 slide by the outwardly extending lobes 11 without contact (i.e. contactless) during rotation of the inner 102 and outer 103 gerotors in operation of the gerotor set 112. This case of maintaining a set distance 118 between the surfaces 115,116 for a generic gerotor set 112 is defined as a work gerotor set 304 (see Figure 1c). In this case the surface 116 of the inner gerotor 102 at the position of the line seals 111,104 is maintained the set standoff distance 118 (see Figure 9b) from the adjacent surface 115 of the outer gerotor 103, in the absence of a hydraulic lubrication film 117 positioned (or otherwise intervening) in the standoff distance 1 8, by using a sync gerotor set 305 connected to the work gerotor set 304 using the inner 120 and outer 122 mounting members as described by example. Corotation (e.g. at the same angular speed) of the inner gerotor 102 of the gerotor sets 304,305 (e.g. synch to work) and/or between gerotor sets 304,304 (e.g. work to work) is provided due to the mechanical connection between the respective inner gerotors 102 by the inner mounting member 120 (e.g. shaft). It is recognised that the inner mounting member 120 can be structurally or otherwise fixedly connected (e.g. welded, bolted, adhered or otherwise rigidly fastened) to the two adjacent inner gerotors 102 and/or can be magnetically connected as desired. Corotation (e.g. at the same angular speed) of the outer gerotor 103 of the gerotor sets 304,305 (e.g. synch to work) and/or between gerotor sets 304,304 (e.g. work to work) is provided due to the mechanical connection between the respective outer gerotors 103 by the outer mounting member 122 (e.g. corotor bearing mechanism). It is recognised that the outer mounting member 122 can be structurally or otherwise fixedly connected (e.g. welded, bolted, adhered or otherwise rigidly fastened) to the two adjacent outer gerotors 102 and/or can be magnetically connected as desired.

[0049] The work gerotor set 304 can be defined as a generic gerotor set 12 that is configured to have rotation of both of the gerotors 02,103 of the gerotor set 304 be driven gerotors, such that rotation of the gerotors 102,103 of the same gerotor set 304 are driven independently of one another as they are maintained the set standoff distance 18 from one another (i.e. in the absence of forces exerted along the nominal line seals 1 1 1 ,104 due to direct or indirect contact between the lobes 109,111 with respective adjacent lobes 111 ,109 of the gerotors 02, 03 of the same gerotor set 304). In other words, the inner gerotor 102 of the synchronization gerotor set 305 drives the rotation (e.g. corotation) of the inner gerotor 102 of the work gerotor set 304 via the inner mounting member 20 as torque between the inner gerotors 102 is transferred there-between through the inner mounting member 120 and the outer gerotor 103 of the synchronization gerotor set 305 drives the rotation (e.g. corotation) of the outer gerotor 03 of the work gerotor set 304 via the outer mounting member 122 as torque between the outer gerotors 103 is transferred there-between through the outer mounting member 122. [0050] In the case where two work gerotor sets 304 are coupled to one another, the inner gerotor 102 of the work gerotor set 304 drives the rotation (e.g. corotation) of the inner gerotor 102 of the attached work gerotor set 304 via the inner mounting member 120 as torque between the inner gerotors 102 is transferred there-between through the inner mounting member 120 and the outer gerotor 103 of the work gerotor set 305 drives the rotation (e.g. corotation) of the outer gerotor 103 of the attached work gerotor set 304 via the outer mounting member 122 as torque between the outer gerotors 103 is transferred there-between through the outer mounting member 122.

[0051] Referring to Figure 1c, due to the coupling of the inner gerotor 102 of the first work gerotor set 304 with the adjacent inner gerotor 102 of the synch gerotor set 305 via the mounting member 20 and the coupling of the inner gerotor 102 of the first work gerotor set 304 with the adjacent inner gerotor 102 of the second work gerotor set 304 via the mounting member 120, the inner gerotors 102 of the work gerotor sets 304 are driven by the inner gerotor 102 of the synch gerotor set 305 around the same first fixed axis 106. Further, due to the coupling of the outer gerotor 03 of the first work gerotor set 304 with the adjacent outer gerotor 103 of the synch gerotor set 305 via the mounting member 122 and the coupling of the outer gerotor 103 of the first work gerotor set 304 with the adjacent outer gerotor 103 of the second work gerotor set 304 via the mounting member 122, the outer gerotors 103 of the work gerotor sets 304 are driven by the outer gerotor 103 of the synch gerotor set 305 around the same second fixed axis 113.

[0052] In an alternative embodiment, see Figure 1d, it is recognized that the inner gerotor assembly 130 and the outer gerotor assembly 132 can be configured as the synch gerotor set 305 positioned between a pair of work gerotor sets 304, such that the stacked gerotor configuration has at least three gerotor sets fixedly coupled to one another. Therefore, due to the coupling of the inner gerotor 102 of the first work gerotor set 304 with the adjacent inner gerotor 102 of the synch gerotor set 305 via the mounting member 120 and the coupling of the inner gerotor 102 of the synch gerotor set 305 with the adjacent inner gerotor 102 of the second work gerotor set 304 via the mounting member 120, the inner gerotors 102 of the work gerotor sets 304 are driven by the inner gerotor 102 of the synch gerotor set 305 around the same first fixed axis 106. Further, due to the coupling of the outer gerotor 103 of the first work gerotor set 304 with the adjacent outer gerotor 103 of the synch gerotor set 305 via the mounting member 122 and the coupling of the outer gerotor 103 of the synch gerotor set 305 with the adjacent outer gerotor 103 of the second work gerotor set 304 via the mounting member 122, the outer gerotors 103 of the work gerotor sets 304 are driven by the outer gerotor 103 of the synch gerotor set 305 around the same second fixed axis 13.

[0053] In an alternative embodiment, see Figure 1e, it is recognized that the inner gerotor assembly 130 and the outer gerotor assembly 132 can be configured as two synch gerotor sets 305 and one work gerotor set 304, such that the work gerotor set 304 is positioned between (as shown) or on one side (not shown) of the two synch gerotor sets 305, such that the stacked gerotor configuration has at least three gerotor sets fixedly coupled to one another. This variation on the design to have a sync gerotor set 305 pair symmetrically on each side of the work gerotor set 304 can provide for better balance and distribute forces and wear on the contact surfaces.

[0054] In all of the examples for the stacked gerotor configuration shown in Figured 1c,d,e, these can be referred to as non-cantilevered as mounting members 120,122 are positioned on either side of the inner 102 and outer 103 gerotors.

[0055] With reference now to Fig. 2, there is shown in exploded isometric view a cantilevered gerotor mechanism 200 which comprises an inner gerotor 207 and an eccentrically disposed outer gerotor 206 contained within encasement segment 204. Outer gerotor 206 is concentrically affixed to a shaft 205, which is held by bearings 201 and 203 contained within encasement segment 202, and inner gerotor 207 is

concentrically affixed to a shaft 208, which is held by bearings 209 and 211 contained within encasement segment 210. Casing segment 210 has an axial low-pressure port 213 and an axial high-pressure port 212. Inner gerotor 207 and outer gerotor 206 are held by this assembly in both axial and radial directions on their respective shafts to hold radial and axial clearances between inner gerotor 207, outer gerotor 206, and encasement segments 202, 204 and 210. [0056] With reference now to Figs. 5A and 5B, there is shown a gerotor set 500 which consists of an outer gerotor 501 and an inner gerotor 503. Outer gerotor 501 has N port holes located radially at the N grooves 505 such that fluids or gases may communicate (e.g. fluid ingress/egress) between inlet and outlet ports (not shown) located radially through the enclosure and the N displacement volumes 107 (see Fig.1 ). A shaft hole 504 is located centrally and axially through the inner gerotor 503. In this example gerotor set 500 the inner gerotor 503 is driven by (or drives) a shaft (e.g.

mounting member 120,122) affixed through shaft hole 503 and the outer gerotor drives (or is driven by) the outer gerotor 501 via contact. The gerotor set 500 can be used in a gerotor mechanism (e.g. pump).

[0057] With reference now to Figs. 1 a,b,c, 3 and 4, there is shown in sectional views a gerotor mechanism defined here as a "CoRotor" mechanism 300 in which a CoRotor set comprises at least one work gerotor set 304, at least one sync gerotor set 305, at least one CoRotor bearing 308 (e.g. outer mounting member 122) and usually at least one shaft bearing 312, all mounted on a common shaft 309 (e.g. inner mounting member 20) and all contained within an enclosure 301. In this example, the inner gerotor assembly 130 only has mounting members 120 and a pair of inner gerotors 302, 307 and the outer gerotor assembly 132 only has mounting members 122 and a pair of outer gerotors 303, 306.

Work Gerotor Sets 304

[0058] A work gerotor set 304 comprises an inner gerotor 302 concentrically affixed to shaft 309 and an eccentrically disposed outer gerotor 303 affixed to the outer gerotor bearing 315 of the CoRotor bearing 308, which is used to preferably compress or expand compressible fluid, as compared to a synch gerotor set 305 that is coupled to the work gerotor set 304 and is preferably used to pump incompressible or hydraulic fluid.

[0059] In operation, the radial dimensions of the inner and outer work gerotors 302 and 303 are such that there is positive clearance 1 18 (see Figure 9b) at the N + 1 nominal line seals 104, 320 between the inner work gerotor 302 and the outer work gerotor 303. The inner and outer work gerotors approach each other closely without contact at the nominal line seals with the clearance 18 preferred to be as small as practical in order to minimize the leakage of working compressible fluid past the nominal seal lines 04, 320, while friction and wear is minimized between the co-rotating inner and outer work gerotors 302 and 303. An example of the preferred positive clearance 1 18 is from one to one hundred micrometers.

[0060] Leakage of the fluid (liquid or gas) past the nominal seal lines 104, 320 and 319 as a percentage of the total fluid volume passing through the a gerotor set 304 will vary directly with the ratio of the surface area to the volume of the displacement chambers 107, which in turn varies directly with the radius of the gerotor set 304.

Therefore, the preferred clearance 1 18 between inner and outer work gerotor sets 304 is smaller for gerotor sets 304 of smaller radius. It can be fortunately relatively easier (less costly) to maintain precision and small clearances between the surfaces of smaller mechanisms, also roughly in direct proportion to the radial dimension of the gerotor set 304, which can partially or wholly offset the leakage effect of increasing surface area to volume ratio of the displacement chambers 107.

Sync Gerotor Sets 305

[0061] A sync gerotor set 305 comprises an inner gerotor 307 affixed to shaft 309 (e.g. inner mounting member 120) and an eccentrically disposed outer gerotor 306 affixed to the outer gerotor bearing 315 of the CoRotor bearing 308 (e.g. outer mounting member 122). The contacting surfaces of the sync gerotor set 305 can be lubricated to minimize wear and friction. The sync gerotor set 305 can act as a pump, pumping a cooling and lubricating fluid or fluids (gas or liquid) through the sync gerotor set 305 to cool and lubricate contacting surfaces 1 15,1 16. It is recognized that in the case of the synch gerotor set 305 using a compressible lubricating fluid, direct contact can be experienced between the lobes 109,1 11 of the gerotors 306,307. It is recognized that in the case of the synch gerotor set 305 using an incompressible lubricating fluid, indirect contact can be experienced between the lobes 109,1 11 of the gerotors 306,307, such that the thickness of lubricating film 17 (see Figures 9a, b) can be the same or less than the standoff distance 1 18 experienced between the lobes 109,1 1 1 of the work gerotors 304.

[0062] In operation, the radial dimensions of the inner and outer sync gerotors

307 and 306 are such that there can be nominally no or little clearance at the N + 1 nominal line seals 104, 319 between the inner sync gerotor 307 and the outer sync gerotor 306, so that the inner and outer sync gerotors 307 and 306 mechanically contact each other at the nominal line seals and mechanical forces can be transmitted between inner and outer sync gerotors 307 and 306 to provide for one drive and one driven gerotor of the same gerotor set 305. Uniform contact can be maintained as precisely as practical at the N + 1 line seals 104, 319 in order to distribute mechanical forces evenly to minimize friction forces and to minimize wear between contacting surfaces.

[0063] The radial dimensions of the sync gerotor set 305 is shown as being equal to the radial dimensions of the work gerotor set 304, however, in general the radial dimensions of the sync gerotor set 305 can be scaled to a different size than the radial dimensions of the work gerotor set 304 providing N is the same for both the sync gerotor set 305 and the work gerotor set 304.

[0064] In general, the axial width of the sync gerotor set 305 can be different than the axial width of the work gerotor set 304. An axially wider sync gerotor set 305 can distribute mechanical forces over a larger axial contact area, decreasing the rate of wear. The trade-off is that a dimensionally larger sync gerotor set 305 uses more in the way of materials, and results in increased physical size and weight. The volume flow of cooling and lubricating fluids through the sync gerotor set 305 can also tend to decrease with decreasing sync gerotor size. It will be obvious to those skilled in the art that the preferred axial and radial dimensions of the sync gerotor set 305 are determined by the optimum safe trade-off of all of these factors for a particular application.

CoRotor Bearing 308 [0065] With reference now to Figs. 3 and 4, there is shown in sectional views examples of the mounting member(S) 122 (see Figure 1c), where dashed line 318 is the section line for Fig 4 and dashed line 3-3 is the section line for Fig 3. A CoRotor bearing 308, 41 1 can comprise i) an encasement ring bearing 316, 402 affixed (e.g. concentric) to the outer gerotors 303, 306, the external surface of which is affixed to the encasement 301 , 401 , and the internal surface of which is affixed to the external surface of an outer gerotor ring bearing 315, 403; ii) the outer gerotor ring bearing 3 5, 403 (e.g. concentric) to the encasement ring bearing 316, 402, the external surface of which is affixed to the encasement 301 , 401 , and the internal surface of which is affixed to the external surface of the CoRotor disk 314, 406; iii) a CoRotor disk 314, 406 (e.g.

concentric) to the encasement ring bearing 316, 402, the external surface of which is affixed to the outer gerotor bearing 315, 403, and the internal surface of which is affixed to the external surface of the CoRotor shaft bearing 313, 404; and iv) a CoRotor shaft bearing 313, 404 (e.g. concentric) to the shaft 309, 405, the external surface of which is affixed to the CoRotor disk 314, 406, and the internal surface of which is affixed to the external surface of the shaft 309, 405.

[0066] Horizontal dashed line 106 is the axis of rotation of the shaft 309.

Horizontal dashed line 106 intersects vertical dashed line 3-3 at the center of rotation of the shaft 405 and the inner gerotors 302 and 307, and horizontal dashed line 113 intersects vertical dashed line 410 at the center of rotation of the outer gerotor bearing 315, 403 and of the outer gerotors 303 and 306.

[0067] For example, if a prime mover, such as an electric motor or combustion engine, is attached to shaft 309, mechanical force will synchronously co-rotate both the inner sync 307 and work 302 gerotors and, since they are both affixed to a common shaft 309 (e.g. common mounting members 120), such that the inner synch gerotor 307 drives the inner work gerotor 302. As a result mechanical force will be transmitted between the inner sync gerotor 307 and the outer sync gerotor 306 at the lubricated contact points at the nominal seal lines 104, 319. Since the outer sync gerotor 306 and the outer work gerotor 303 are both affixed to the outer gerotor bearing 315 of the CoRotor bearing 308 309 (e.g. common mounting members 122), mechanical force will be transmitted between the outer sync gerotor 306 and the outer work gerotor 303 and they will co-rotate synchronously, such that the outer synch gerotor 306 drives the outer work gerotor 303.

[0068] Since both the inner 302 and outer 303 work gerotors co-rotate without contact, i.e. are driven independently of one another, lubrication is not an issue within the work gerotor set 304. Instead, mechanical drive forces between the inner 130 and outer 132 gerotor assemblies are transmitted by lubricated, cooled bearings and sync gerotors 306,307. The work gerotor set 304 of the CoRotor mechanism can therefore be used to pump non-lubricating fluids (liquids or gases). For compressible fluids (gases), the CoRotor mechanism can be used as a compressor, an expander or as a vacuum pump.

[0069] The CoRotor bearing 308, 411 is one example of the outer mounting member(s) 122 of the outer gerotor assembly 132. The CoRotor bearing can be a compound triple-bearing assembly that provides for (i) the shaft 309, 405 and inner rotors 302 and 307 to rotate at one speed; while (ii) the outer gerotor ring bearing 315, 403 and outer gerotors 302 and 306 rotate at a rate that is slower by a factor of 1/(N+1); and also while (iii) the encasement 301 , 401 and the CoRotor disk 314, 406 remain fixed.

[0070] The CoRotor bearing 308, 411 can also act as a sealed barrier between the work gerotor set 304 and the sync gerotor set 305 and each of the component bearings that comprise the CoRotor bearing 308,41 1 are generally sealed bearings in order to prevent or minimize fluid leakage between the work gerotor set 304 and the sync gerotor set 305. However, it is recognized that other seal arrangements for the mounting members 120, 122 can be provided, as desired.

[0071] One advantage of the present invention is relative ease of assembly of the entire mechanism with precision clearances based on the feature that the outer gerotors 103 of the outer gerotor assembly 132 all rotate around the same second fixed axis 13 and the inner gerotors 102 of the inner gerotor assembly 130 all rotate around the same first fixed axis 106 (e.g. since all moving components including all bearings 312, 308, 312 and all gerotor sets 304, 305 are mounted on one common shaft 309). With common fixed axes 106,1 13 provided through coupling of the gerotors 102,103 to one another using respective mounting members 120,122 (e.g. a single common shaft), the stacked gerotor assembly is easier to produce and maintain with precision clearances compared to the use of multiple shafts or multiple shafts with different axes for chained gerotors with external gear sets or alignment mechanisms is the current art and practice of building gerotor mechanisms. In other words, the use of inner 130 and outer 132 gerotor assemblies as described by example for defining common fixed axes 106,1 13 is not shown in the current art, rather separate gerotor systems are connecting using intervening gear sets or other alignment mechanisms that compound the issue of maintaining precision clearances between separate gerotor mechanisms.

[0072] It will be obvious to those skilled in the art that the CoRotor bearings 308, 41 lean be replaced by other sealing designs and bearing designs.

[0073] Referring to Figures 10a, b and 9a, b shown is the inner gerotors 102 and outer gerotors 103 of both the work gerotor pairs 304 and the sync gerotor pairs 305 mounted in fixed relative rotational positions on a shared shaft (or other mounting member 120,122) that can extend through a separating seal between work gerotor and sync gerotor volumes, so that the outer 103 gerotors are mechanically attached so that they rotate together and so that the inner 102 gerotors are mechanically attached so that they rotate together.

[0074] As discussed above, the inner 02 and outer 103 gerotors of the work gerotor set 304 do not contact one another as the rotate. This is accomplished in cooperation with the coupled synchronization gerotor set 305 that maintains this non- contact between the outer surface of the inner work gerotor 102 and the outer surface of the outer work gerotor 103 by a predefined offset distance 1 18 at the contact lines 104,1 0 (see Figure 1a) between the outer surface 5 of the inner work gerotor 102 and the outer surface 1 16 of the outer work gerotor 103 as the inner work gerotor 102 rotates about the first fixed axis 106 and the outer work gerotor 103 rotates about the second fixed axis 113.

[0075] In one embodiment, as shown in Figure 9a, 9b, 10a, there is no relative rotation difference between the inner gerotors 102 of the sync gerotor set 305 and the work gerotor set 304 and therefore the predefined offset distance 1 18 is a consequence of the interposition of a lubrication film thickness 1 17 between the outer surface 115 of the inner synch gerotor 102 and the outer surface 1 16 of the outer synch gerotor 103 at contact lines 104,110 between the outer surface 115 of the inner synch gerotor 102 and the outer surface 1 16 of the outer synch gerotor 103 as the inner synch gerotor 102 rotates about the first fixed axis 106 and the outer synch gerotor 103 rotates about the second fixed axis 113. Further, it is recognized that the predefined offset distance 118 can be equal to or less than the lubrication film thickness 1 17. The actual magnitude of lubrication film thickness 1 17 can be controlled due to a maintained pressure P of the lubrication fluid in the volumes 1 14 of the synch gerotor set 305, such as by maintaining output pressure P in a heat exchanger fluid circuit 140 at the output port by a pressure control mechanism 142 (e.g. by a pressure control valve - fixed or variable) positioned in the circuit. Alternatively or in addition to, the actual magnitude of lubrication film thickness 1 17 can be controlled by the viscosity of the lubrication fluid pumped by the synch gerotor set 305, for example by a flow control mechanism 144 (e.g. flow control valve) and/or temperature control mechanism 146 (e.g. fan and temperature gauge control), as it is recognized that film thickness is proportional fluid viscosity.

[0076] In one embodiment, as shown in Figure 9a, 9b, 10a, there is a relative rotation difference (e.g. an advance or retard depending which set 304,305 is used as the reference) between the inner gerotors 102 of the sync gerotor set 305 and the work gerotor set 304 and therefore the predefined offset distance 118 is a consequence of a fixed rotational degree offset 148 about the first fixed axis 106 between the inner work gerotor 102 and the inner synch gerotor 102 as maintained during rotation by the inner mounting member 120. It is also recognised that the relative rotation difference can be between the outer gerotors 103 of the sync gerotor set 305 and the work gerotor set 304 and therefore the predefined offset distance 1 18 is a consequence of the fixed rotational degree offset 148 about the second fixed axis 113 between the outer work gerotor 103 and the outer synch gerotor 103 as maintained during rotation by the outer mounting member 122. It is also recognised that the relative rotation difference can be between a combination for both the outer gerotors 103 and inner gerotors 102 of the sync gerotor set 305 and the work gerotor set 304 and therefore the predefined offset distance 118 is a consequence of the fixed rotational degree offset 148 about the second fixed axis 113 between the outer work gerotor 103 and the outer synch gerotor 103 as maintained during rotation by the outer mounting member 122 in combination with an additional fixed rotational degree offset 148 about the first fixed axis 06 between the inner work gerotor 102 and the inner synch gerotor 02 as maintained during rotation by the outer mounting member 120.

[0077] Further to the above, it is recognised that the predefined offset distance can be greater that the fixed rotational degree offset 148 due to the presence of the lubrication film thickness 117 between the outer surface 15 of the inner synch gerotor 102 and the outer surface 16 of the outer synch gerotor 03 at contact lines 04, 0 between the outer surface 1 5 of the inner synch gerotor 102 and the outer surface 1 6 of the outer synch gerotor 103.

CoRotor Bravton Cycle Engine 600

[0078] With reference now to Fig. 6, there is shown in sectional view disclosed an improved gerotor Brayton cycle engine defined here as a "CoRotor Brayton cycle engine" 600. One advantage of the CoRotor Brayton cycle engine 600 is relative ease of assembly of the entire mechanism with precision clearances based on the feature that the outer gerotors of the outer gerotor assembly 32 all rotate around the same second fixed axis 113 and the inner gerotors of the inner gerotor assembly 130 all rotate around the same first fixed axis 106. With common fixed axes 106,113 provided through coupling of the gerotors to one another using respective mounting members 120,122 (e.g. shaft 601 and corotor bearing 605, 607). [0079] Preferably at least one synch gerotor set 606 is coupled to at least two work gerotor sets 604,608 in the stacked gerotor set configuration, thereby providing for an inner gerotor assembly 130 having at least three inner gerotors fixedly coupled to one another and the outer gerotor assembly 132 having at least three outer gerotors fixedly coupled to one another, with common fixed axes 106,1 13 provided through coupling of the gerotors (inner or outer) to one another using respective mounting members 120,122.

[0080] The CoRotor Brayton cycle engine 600 incorporating the common shaft 601 can have components of : i) shaft bearings 602 and 609; ii) a compressor work gerotor set 604 for compressing air or any other oxidizing gas; iii) a sync gerotor set 606 for synchronizing all work gerotor sets 604, 608 mounted on the common shaft 601 ; iv) an expander work gerotor set 608 for expanding compressed combustion gases; v) a CoRotor bearing 605 connecting and sealing between the compressor work gerotor set 604 and the sync gerotor set 606; vi) a CoRotor bearing 607 connecting and sealing between the sync gerotor set 606 and the expander work gerotor set 608; vii) and an encasement 603.

[0081] Not shown in Fig. 6 are other components of a working engine: (i) the combustor chamber; (ii) the optional recuperator; (iii) the ducting for gases between components; or (iv) the ducting for lubricating fluid for the sync gerotor, the construction of all of which will be obvious to one skilled in the art.

[0082] Also, the following shall be obvious to one skilled in the art: (i) that the compressor gerotor set 604; the sync gerotor set 606; and the expander gerotor set on the common shaft can be mounted on the common shaft in any order, with intervening gerotor bearings; (ii) that multiple sync gerotors 606 can be used on the common shaft 601 ; and iii) that multiple compressor gerotor sets 604 and multiple expander gerotor sets 608 can be placed in parallel for increased working fluid mass throughput; or in series for increased working fluid pressures.

[0083] For example, if there are three compression stages, and if each compression stage increases pressure by a factor of six, then the first stage compresses a gas from 1 atmosphere to 6 atmospheres, the second stage compresses from 6 atmospheres to 36 atmospheres and the third stage compresses from 36 atmospheres to 216 atmospheres.

[0084] When multiple compressor work gerotor sets 304 are used, intercooling using a heat exchanger can optionally be used between stages to improve engine thermal efficiency. When multiple expander work gerotor sets 304 are used, reheating using hot exhaust gases passed through a heat exchanger (recuperator) can optionally be used between stages to improve engine thermal efficiency.

[0085] With reference now to Fig. 6 and to Fig. 8, a block diagram of a CoRotor Brayton cycle engine 800 is disclosed. One advantage of the CoRotor Brayton cycle engine 800 is relative ease of assembly of the entire mechanism with precision clearances based on the feature that the outer gerotors of the outer gerotor assembly 132 all rotate around the same second fixed axis 1 13 and the inner gerotors of the inner gerotor assembly 30 all rotate around the same first fixed axis 106 (see Figure 1a). With common fixed axes 106,113 provided through coupling of the gerotors to one another using respective mounting members 120 (e.g. shaft 805) and mounting members 22 not shown.

[0086] Preferably at least one synch gerotor set 808 is coupled to at least two work gerotor sets 807,810 in the stacked gerotor set configuration, thereby providing for an inner gerotor assembly 130 having at least three inner gerotors fixedly coupled to one another and the outer gerotor assembly 132 having at least three outer gerotors fixedly coupled to one another, with common fixed axes 106,1 13 provided through coupling of the gerotors (inner or outer) to one another using respective mounting members 120,122.

[0087] The CoRotor Brayton cycle engine 800 incorporates the CoRotor compressor 810, CoRotor synchronizer 808, and CoRotor expander 807 are all mounted on common shaft 805. CoRotor compressor 810, comprises compressor work gerotor set 604; CoRotor synchronizer 808, comprises sync gerotor set 606; and CoRotor expander 807 comprises expander work gerotor set 608. [0088] Ambient air 809 is received and compressed in CoRotor compressor 810, and then counter currently heated in recuperator802 using the thermal energy from exhaust gases from the CoRotor expander 807. In combustor 804, fuel 803 is introduced into the pre-warmed, compressed air and ignited. The high-pressure combustion gases flow into CoRotor expander 807, where work, 806, is produced.

[0089] After the high-pressure combustion gases expand in CoRotor expander 807, the hot exhaust gases flow through recuperator 802, preheating the compressed air flowing from CoRotor compressor 810 to combustor 804. The exhaust gases 801 exit the recuperator802.

CoRotor Brayton Cycle Engine With Integrated CoRotor Compressor/Expander/Pump

[0090] With reference now to Fig. 7, there is shown in sectional view 700 a CoRotor Brayton cycle engine 713 with an integrated CoRotor device 712 mounted on a common shaft 701.

[0091] One advantage of the CoRotor Brayton cycle engine 713 is relative ease of assembly of the entire mechanism with precision clearances based on the feature that the outer gerotors of the outer gerotor assembly 132 all rotate around the same second fixed axis 1 13 and the inner gerotors of the inner gerotor assembly 130 all rotate around the same first fixed axis 106. With common fixed axes 106,113 provided through coupling of the gerotors to one another using respective mounting members 120 (e.g. shaft 701) and mounting members 122.

[0092] Preferably at least one synch gerotor set 706 is coupled to at least three work gerotor sets 704,708,710 in the stacked gerotor set configuration, thereby providing for an inner gerotor assembly 130 having at least three inner gerotors fixedly coupled to one another and the outer gerotor assembly 132 having at least three outer gerotors fixedly coupled to one another, with common fixed axes 106,1 13 provided through coupling of the gerotors (inner or outer) to one another using respective mounting members 120,122. [0093] The CoRotor Brayton cycle engine 713 incorporates the common shaft 701 mounted on shaft bearings 702 and 71 1 , and all components are enclosed by encasement 703. The CoRotor Brayton cycle engine 713 comprises i) a CoRotor compressor 704 for compressing air or any other oxidizing gas; ii) a CoRotor synchronizer 706 for synchronizing all work gerotor sets 704, 708 and 710; iii) a CoRotor expander 708 for expanding compressed combustion gases; iv) a CoRotor bearing 705 connecting and sealing between the CoRotor compressor 704 and the CoRotorsynchronizer706; v) a CoRotor bearing 707 connecting and sealing between the CoRotorsynchronizer706and the CoRotor expander 708.

[0094] The integrated CoRotor device 712 comprises a work gerotor set 710 and a CoRotor bearing 709 connecting and sealing between the CoRotor expander 708 of the CoRotor engine 713 and the work gerotor set of the CoRotor device 710

[0095] While the invention has been described in terms of its preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the described invention.