FIELD OF THE INVENTION [0002] The present invention relates generally to turbines and more particularly (but not exclusively) to turbines utilizing jet propulsion for rotation and methods of operating such turbines.

BACKGROUND OF THE INVENTION [0003] Conventional turbine and rotary vane motor technology utilize a working fluid to apply a force against turbine blades or vanes in order to drive the turbine or rotary vane motor. Due to the delicate nature of their blades and vanes, however, these conventional turbines and rotary vane motors are generally not suited for use with high-pressure or dual phase working fluids.

High-pressure working fluids can damage the turbine blades or vanes.

Additionally, a portion of the working fluid can bypass the surfaces of the blades or vanes entirely, as it is sometimes difficult to provide an adequate machine tolerance between the blades or vanes and the housing of the turbine or rotary vane motor. Potential energy of the high-pressure working fluid can thus be lost due to the pressure reduction caused by such bypass.

SUMMARY OF THE INVENTION [0004] In one embodiment, a turbine includes a rotatable vessel and at least one outlet for discharging pressurized working fluid from the rotatable vessel to a lower pressure area to produce jet propulsion for rotating the rotatable vessel.

[0005] In another embodiment, a turbine includes a shaft and a rotatable vessel. The shaft has a fluid passage extending through at least a portion thereof for delivering a pressurized working fluid through the shaft to the rotatable vessel.

[0006] In another embodiment, a turbine includes a vessel and at least one outlet for discharging pressurized working fluid from the vessel to a lower pressure area to produce jet propulsion for rotating the vessel. The turbine also includes a ring positioned generally around the vessel within the lower pressure area such that pressurized working fluid discharged from the vessel will contact the ring and rotate the ring in a direction generally opposite to a direction of rotation of the vessel.

[0007] In another form, the present invention provides a method of operating a turbine having a vessel. In one embodiment, the method generally includes discharging a pressurized working fluid from the vessel to a lower pressure area, the discharging of the pressurized working fluid producing jet propulsion for rotating the vessel.

[0008] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples below, while indicating exemplary embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS [0009] The present invention will be more fully understood from the detailed description and the accompanying drawings, wherein: [0010] FIG. 1 is a side cross-sectional view of a turbine according to one embodiment of the invention; [0011] FIG. 2 is an upper cross-sectional view of the rotatable vessel and shaft shown in FIG. 1; [0012] FIG. 3 is an upper plan view of a support plate ; [0013] FIG. 4 is a partial side cross-sectional view of a turbine according to another embodiment of the invention; [0014] FIG. 5 is a side cross-sectional view of a turbine according to another embodiment of the invention; and [0015] FIG. 6 is an upper cross-sectional view taken along the plane 6- 6 in FIG. 5; and [0016] FIG. 7 is an upper cross-sectional view of a turbine according to another embodiment of the invention.

[0017] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS [0018] A turbine according to one aspect of the invention includes a rotatable vessel and at least one outlet for discharging pressurized working fluid from the rotatable vessel to a lower pressure area to produce jet propulsion for rotating the rotatable vessel. Accordingly, certain embodiments of the invention provide turbines which utilize jet propulsion (i. e. , the ejection of mass at high velocity) for rotation, and thus do not require use of blades or vanes for rotation (i. e. , the turbines may but need not be bladeless). Thus, the present invention provides turbines that efficiently utilize substantially all of the working fluid and which are also suitable for use with high pressure and/or dual phase working fluids. The high operating pressures at which turbines of the present invention can be operated allow significant amounts of power to be generated in generally far less space.

[0019] A turbine according to another aspect of the invention includes a shaft and a rotatable vessel. The shaft has a fluid passage extending through at least a portion thereof for delivering a pressurized working fluid through the shaft to the rotatable vessel. In this manner, the manufacture and operation of the turbine is enhanced.

[0020] An exemplary turbine embodying several aspects of the invention is illustrated in FIG. 1 and is indicated generally by reference character 100. As shown in FIG. 1, the turbine 100 includes a rotatable vessel 102 and a plurality of outlets 104 extending through an outer surface 116 of the vessel 102.

During operation of the turbine 100, the outlets 104 discharge pressurized working fluid 106 from the vessel 102 to a lower pressure area 108 to produce jet propulsion for rotating the vessel 102. The lower pressure area 108 has a pressure lower than the pressure of the working fluid 106 within the vessel 102.

[0021] The amount of energy derived from the jet propulsion is a function of the mass and the velocity at which the mass is discharged from the vessel 102 through the outlets 104 (i. e. , the greater the mass and higher the velocity, the greater the jet propulsion force or thrust in the opposite direction). In at least some embodiments, the vessel 102 is bladeless with rotation of the vessel 102 being accomplished solely through the jet propulsion generated by the discharge of the working fluid through the outlets 104. In these embodiments, the

working fluid preferably does not apply a force against a blade or vane as in a conventional turbine. In other embodiments, the vessel may have one or more blades such that rotation of the vessel is accomplished through both the discharge of working fluid from the vessel and through working fluid applying a force against one or more blades of the vessel.

[0022] The outlets 104 are each oriented to discharge the pressurized working fluid from the vessel 102 in a direction (indicated by arrow 112) generally opposite to the rotational direction (indicated by arrow 110 in FIG. 2) of the vessel 102. The working fluid jets generally backward from the outlets 104 to the lower pressure area 108 causing an equal and opposite thrust in the forward direction to rotate the vessel 102.

[0023] Each outlet 104 includes a narrow nozzle 114 such that the velocity of the working fluid increases as it passes through the nozzle 114.

Alternatively, the outlets may consist of suitably sized and spaced apertures.

[0024] In the particular illustrated embodiment, the vessel 102 includes sixteen outlets 104 generally evenly spaced around the outer surface 116 of the vessel 102. Alternatively, any suitable number of (i. e. , one or more) outlets 104 can be used depending at least in part on the particular flow rates and operating pressures used for the turbine. Consequently, the present invention should not be regarded as limited to the particular number of outlets shown and described.

[0025] The size of the outlets 104 can also vary depending, at least in part, on the dimensions of the vessel 102, as the turbine 100 is salable to a wide range of sizes and configurations.

[0026] To form the vessel 102 and the outlets 104, the turbine 100 includes a plurality of irregularly shaped plates 118 (FIG. 2) arranged to form the outlets 104 and a plurality of discs 120 (FIG. 3). The plates 118 are mounted adjacent the outer surface 116 of the vessel 102. The discs 120 are coupled to the plates 118. The discs 120 are alternately spaced between corresponding pairs of the plates 118 as shown in FIG. 1.

[0027] Rods 122 penetrate through holes 124 defined within the discs 120 and plates 118 to couple the discs 120 and plates 118 to one another. In this manner, the discs 120 and plates 118 form a generally cylindrical or drum shaped vessel 102, although other shapes can be employed for the vessel.

[0028] The discs 120 are also coupled to a shaft 126 for common rotation therewith. The discs 120 are mounted on the shaft 126 via keyway pins (not shown) engaged with keyways 128 (FIG. 2) defined by the shaft 126 and with keyways 130 (FIG. 3) defined by the discs 120.

[0029] As shown in FIGS. 1 and 3, each of intermediate discs define openings or pressure equalization ports 132 therethrough. The pressure equalization ports 132 allow the working fluid 106 to generally evenly disburse within the vessel 102 so that each outlet 104 may operate at about an equal pressure.

[0030] In the particular embodiment under discussion, permanent magnet rotors 134 are coupled to each end of the vessel 102 by the rods 122.

[0031] As shown, the rods 122 penetrate through the discs 120, plates 118, and permanent magnet rotors 134 such that application of torque to the rods 122 laterally compresses and thus couples the discs 120, plates 118, and rotors 134 to one another.

[0032] In the embodiment shown in FIGS. 1-3, the vessel 102 includes sixteen outlets 104. Specifically, the vessel 102 includes four sections along its outer circumference, with each section defining four outlets 104. Each section is defined between two end discs and separated by three intermediate discs.

Again, however, the turbine may include more or less outlets, sections, end discs, and intermediate discs. For example, the vessel 102 shown in FIG. 7 includes twelve sections.

[0033] With further reference to FIG. 1, the shaft 126 includes a fluid passage 136 extending through at least a portion of the shaft 126. The shaft 126 has an open end 138 for receiving working fluid 140 into the fluid passage 136.

The opposite end 142 of the shaft 126 is capped. The shaft 126 also includes a sidewall 144 defining a plurality of radially extending passageways 146 therethrough for discharging the pressurized working fluid from within the shaft's fluid passage 136 into the vessel 102. Other configurations can be employed for delivering fluid to the vessel through a shaft.

[0034] The shaft 126 is mounted on bearings 148 and 150 which are, in turn, mounted to the turbine housing 152. The bearings 148 and 150 are preferably ceramic bearings that accommodate high rotational speeds.

[0035] Seals 154 are located at the open end 138 of the shaft 126 to prevent the escape of pressurized working fluid 140. The seals 154 form a cavity 156 into which is provided a pressurized hydraulic fluid 158 to create a hydraulic seal for retaining high pressurized working fluid within the turbine 100. This is accomplished through an equalization of the working fluid 140 pressure and the hydraulic fluid 158 pressure within the cavity 156, and because there is essentially no pressure differential between the opposed sides of the seals 154 between the hydraulic fluid 158 and the working fluid 140. Further, a greater viscosity of the hydraulic fluid 158 as compared to the working fluid allows the hydraulic fluid 158 to be readily sealed within the cavity 156. In this manner, the potentially combustible and explosive high pressure working fluid is preferably retained within the turbine 100.

[0036] In the illustrated embodiment of FIG. 1, the turbine 100 is configured such that the vessel 102 is generally horizontal with the open end 138 of the shaft 126 directed generally downward. In this configuration, the mass of the turbine 100 opposes the upward lifting force generated by the pressurized working fluid contacting the shaft's capped end 142. If the pressure of the working fluid is sufficiently high enough, roller bearings (not shown) can be installed between the shaft's capped end 142 and the turbine housing 152 to prevent damage to the rotary thrust bearings 148 and 150, among other components of the turbine 100.

[0037] Stators 160 are mounted to the turbine housing 152 adjacent to and in axial alignment with rotors 134 coupled to each end of the vessel 102.

Electrical current 161 is thus generated when the rotation of the vessel 102 causes rotation of the rotors 134 relative to the stators 160. In other embodiments, the stators may be, for example, radially aligned with the rotors instead of axially aligned as shown in FIG. 1.

[0038] Operation of the turbine 100 shown in FIG. 1 will now be provided. Pressurized working fluid 140 (e. g. , gas, liquid, or a combination thereof) enters the turbine 100 and flows through the shaft's open end 138 into the fluid passage 136 within the shaft 126. The pressurized working fluid 140 is discharged through holes 146 in the shaft's sidewall 144 into the vessel 102. The

pressurization ports 132 allow the pressurized working fluid 106 to generally evenly disburse within the vessel 102.

[0039] The pressurized working fluid 106 is discharged from within the vessel 102 through the outlets 104, which produces jet propulsion that rotates the vessel 102. The rotation of the vessel 102 rotates the rotors 134 relative to the stators 160 thereby generating electrical current. Further, the rotation of the vessel 102 also rotates the shaft 126, which may used to output mechanical power. The working fluid 162 exits the turbine 100 through exhaust 164.

[0040] FIG. 4 illustrates another exemplary embodiment of a turbine 200 that embodies several aspects of the invention. As shown in FIG. 4, the turbine 200 includes a rotatable vessel 202 having outlets for discharging pressurized working fluid 206 from the vessel 202 to a lower pressure area 208 to produce jet propulsion for rotating the vessel 202. The lower pressure area 208 has a pressure lower than the pressurized working fluid 206 within the vessel 202.

[0041] Additionally, the turbine 200 also includes rotors 234 and stators 260 adjacent to and axially aligned with one another. As shown, the stators 260 each includes at least one fluid passage 262 for receiving a portion of the pressurized working fluid after it is discharged from the vessel 202 via the outlets.

Accordingly, the discharged pressurized working fluid flows through and around the stators 260 and around the rotors 234 thereby cooling the stators 260 and rotors 234 via heat exchange, for example, by removing heat produced during generation of electrical current. The working fluid then exits the turbine 200 via outlet 264.

[0042] By way of example, the working fluid used in the turbine 200 <BR> <BR> may comprise a cryogenic fluid (e. g. , in a liquid and/or gas phase). The cryogenic working fluid can be used to not only produce the jet propulsion force for rotating the vessel, but also to at least maintain superconducting materials in the stator and rotor at superconducting temperatures (i. e., temperatures low enough that the stator and rotor are superconducting).

[0043] The cryogenic working fluid expands as it exits the vessel 202 and enters the lower pressure area 208. This expansion further reduces the temperature of the cryogenic working fluid. The cryogenic working fluid then

flows through the fluid passages 262 of the stators 260 and around the rotors 234 to provide cooling through heat exchange. The superconducting materials forming the stator 260 and rotor 234 are thus maintained at superconducting temperatures.

[0044] FIG. 5 illustrates another exemplary embodiment of a turbine 300 that embodies several aspects of the invention. As shown in FIG. 5, the turbine 300 includes a rotatable vessel 302 and outlets 304 for discharging pressurized working fluid from the vessel 302 to a lower pressure area 308 to produce jet propulsion for rotating the vessel 302. The lower pressure area 308 has a pressure lower than the pressure of the working fluid 306 within the vessel 302.

[0045] The turbine 300 also includes a ring 366 positioned generally around the vessel 302 within the lower pressure area 308 such that pressurized working fluid discharged from the vessel 302 will contact the ring 366 and rotate the ring 366 in a direction (indicated by arrow 368 in FIG. 6) generally opposite to a direction of rotation (indicated by arrow 370 in FIG. 6) of the vessel 302. As described below, the inner surface 372 of the ring 366 is shaped to harness and be driven by the kinetic energy of the working fluid discharged from within the vessel 302.

[0046] Because the turbine 300 accomplishes rotation of the vessel 403 by ejecting mass at high velocity through the outlets 304, the working fluid still possesses significant potential kinetic energy to perform work in the conventional sense of applying a force against a blade or vane once it is rejected from the vessel 302. In the turbine 300, working fluid is used not only to produce jet propulsion for rotating the vessel 302 but also to apply a force against the ring's inner surface 372 for counter-rotating the ring 366. Accordingly, the ring 366 provides the turbine 300 with an additional power cycle for deriving additional energy from the working fluid. Thus, the turbine 300 is capable of obtaining greater energy output from an equal supply of high pressure working fluid than many conventional turbines.

[0047] With further reference to FIG. 5, the ring 366 can also include one or more outlets 374 for discharging pressurized working fluid from an area 376 between the ring 366 and the vessel 302 to a lower pressure area 378 (i. e.,

an area having a lower pressure than the pressure of the working fluid within the area 376 between the ring 366 and the vessel 302) to produce jet propulsion for rotating the ring 366. In this manner, the ring 366 allows the turbine 300 to derive even further additional energy from the working fluid.

[0048] Each of the outlets 374 of the ring 366 can include a narrow nozzle such that the velocity of the working fluid increases as it passes through the nozzle. Alternatively, the outlets may consist of suitably sized and spaced apertures.

[0049] The vessel 302 and the ring 366 can each include any suitable <BR> <BR> number of (i. e. , one or more) outlets 304 and 374, respectively, depending at least in part on the flow rates and operating pressures of the particular application in which the turbine will be used. Consequently, the present invention should not be regarded as limited to the particular number of outlets shown and described.

Further, the size of the outlets 304 and 374 can also vary depending, at least in part, on the dimensions of the vessel 304 and the ring 366, as the turbine 300 is salable to a wide range of sizes and configurations.

[0050] In the particular illustrated embodiment of FIGS. 5 and 6, the pressurized working fluid 375 enters the turbine 300 and flows through an open end 338 of a shaft 326. The pressurized working fluid then flows through a fluid passage 336 within the shaft 326. The pressurized working fluid is discharged from the shaft 326 through holes 346 in the shaft sidewall into the vessel 302.

The pressurized working fluid 306 is allowed to evenly disburse within the vessel 302 as the fluid flows to the outlets 304 through which the working fluid exits the vessel 302.

[0051] The relatively high velocity working fluid that jets from within the vessel 302 through the outlets 304 applies a force against the ring 366, which is located on the outer circumference of the vessel 302 and thus surrounds the vessel 302. This force causes the ring 366 to be pushed and rotated in a direction opposite to the rotational direction of the vessel 302.

[0052] The working fluid exits the ring 366 via outlets 374 to lower pressure 378 within the turbine housing 352 and produces jet propulsion for rotating the ring 366. Thereafter, the working fluid exits the turbine housing 352 through exhaust 364.

[0053] The outlets 374 of the ring 366 discharge the working fluid in a direction that is opposite the rotational direction 368 of the ring 366. This provides at least some benefit by producing jet propulsion for aiding in the rotation of the ring 366.

[0054] As shown in FIG. 6, spacers 379 are provided within the vessel 302 to help direct the flow of the pressurized working fluid within the vessel 302 towards the outlets 304. The direction of the flow of the working fluid through the turbine 300 is represented by arrows.

[0055] The right side plate 380 of the ring 366 is connected via keyway pins 381 to a ring shaft 382 positioned generally around the main shaft 326. The ring shaft 382 is mounted to the main shaft 326 via bearings 383 located between the inside of ring shaft 382 and the outside of the main shaft 326. The ring shaft 382 and ring 366 coupled thereto both rotate counter to the main shaft 326.

[0056] The left side plate 384 of the ring 366 is attached to the main shaft 326 via bearing set 385, but remains free to rotate independent of the main shaft 326. Plates 380 and 384 and the ring 366 rotate in a direction opposite to the rotational direction of the main shaft 326, which is connected to the vessel 302.

[0057] The main shaft 326 and the ring shaft 382 extend out of the right side of the turbine housing 352. The main shaft 326 extends outwardly beyond the ring shaft 382 and is thus accessible. Vee packing 386 and lip seals 387 are located between the inside of ring shaft 382 and the outside of the main shaft 326 in order to maintain proper sealing of the working fluid within the turbine 300 and to keep the bearings 383 lubricated.

[0058] Once the working fluid expands into the turbine housing 352 after already being discharged from both the vessel 302 and then the ring 366, the pressure of the working fluid is dramatically reduced as compared to the pressure of the working fluid within the vessel 302. Nevertheless, the pressure of the working fluid within the turbine housing 352 may still be high enough such that high pressure Vee packing seals 386 may be required.

[0059] In the particular embodiment shown in FIGS. 5 and 6, an electrical generator or turbo-alternator is formed by having a stator 360 connected to the ring shaft 382 via key pins 388 and by having a rotor 334

connected to the main shaft 326 via key pins 389. During operation of the turbine 300, the stator 360 and rotor 334 rotate in opposite directions. The rotational velocity of the generator is thus equal to the combined rotational speeds of the vessel 302 and the ring 366. Accordingly, the amount of electrical current generated is increased as a result of the increased surface rotational velocity between the stator 360 and rotor 334.

[0060] In other embodiments, the turbine may generate electricity by having a rotor coupled to the ring and a stator coupled to a stationary portion of the turbine, such as the turbine housing.

[0061] In addition or alternatively to electricity generation, the main shaft 326 can be used to output mechanical power.

[0062] With further reference to FIG. 5, proper alignment of the stator 360 to the rotor 334 is maintained by way of the bearings 390 and seals 391 located between the outside of the shaft 326 and the inside of the stator 360.

The bearings 390 allow the stator 360 to freely turn about the shaft 326, thereby allowing the shaft 326 and stator 360 to counter-rotate relative to one another.

[0063] Grease fitting 392 is provided to lubricate the bearings 390. The lubrication is retained and maintained in fluid communication with the bearings 383 by the lip seals 391.

[0064] An electrical contact ring 393 is mounted on an electrical contact ring housing 394 bolted to the outside of the turbine housing 352. The electrical contact ring 393 provides an electrical connection between the stator 360 and the electrical power output 395 so that a supply of generated electrical power may be removed from the stator 360. The electrical power output 395 may be either DC or AC current.

[0065] The housing 352 of the turbine 300 generally includes two main concave shells that are bolted together via a bolted flange 396 to form a pressure vessel. Spent working fluid is allowed to exit the housing 352 via flanged exhaust port 364.

[0066] The turbine 300 also includes several additional components bolted to the housing 352 to provide support plates for the mounting of bearings and seals as required. The turbine 300 includes a mandrel 397, a female adapter 398 bolted to the mandrel 397, and an electrical contact housing 394.

[0067] The vessel 302 and the counter-rotating ring 366 are constructed from generally flat parts, that are preferably precision laser cut and that are laterally connected together via bolts 399. The bolts 399 penetrate through holes 301, preferably precision laser cut, within the ring 366, the discs 320, spacers 379 and the plates 318 forming the outlets 304. The bolts 399 have nuts 303 located on the ends thereof. The nuts 303 and bolts 399 are maintained at a substantially uniform torque in order to substantially uniformly compress the various machine parts from which the vessel 302 and ring 366 are formed.

[0068] The flat parts when bolted together form a generally drum shaped vessel 302 having a substantially uniform radial assembly and good rotational balance. The nuts 303 are preferably welded to the bolts 399 with material being removed from the bolt heads as needed to balance the vessel 302. The counter-rotating ring 366 can be constructed in a similar manner, but the ring 366 is attached to and rotates with the ring shaft 382 positioned generally around the main shaft 326.

[0069] The ring 366 includes an inner surface 372 having a plurality of generally outwardly extending surfaces 305 for contacting the pressurized working fluid discharged from within the vessel 302 by the outlets 304.

[0070] In the illustrated embodiment of FIG. 6, the ring inner surface 372 includes a plurality of inverted areas or"V"shapes 305 that provide surfaces at about ninety degrees in relation to the working fluid being discharged from the outlets 304. As the working fluid exhausts from the vessel 302 at greater velocity than the rotation speed of the vessel 302, the working fluid 307 applies a force against the"V"shaped surfaces 305 causing the ring to rotate in the direction in which the working fluid is applied. To prevent the working fluid from bypassing the V-shaped surfaces, a close machine tolerance is preferably maintained between the outside of the vessel 302 and the inwardly most extending portions of the ring inner surface 372.

[0071] Vee packing 307 is located between the outside of the vessel's plates 320 and the inside of the ring's plates 380 and 384 to provide sealing of the working fluid from passage between the outside of the vessel's support plates 320 and the inside of the ring's plates 380 and 384. The trapped working fluid is thus allowed to apply greater force against the ring 366 because a pressurized

chamber 309 is formed between the outside of the vessel 302 and the inside of the ring 366. The pressure within the chamber 309, which is formed by the pressurized working fluid, applies a force against the inside surface 372 of the ring 366 causing the ring 366 to rotate in the direction indicated by arrow 368.

[0072] The pressurized working fluid within the chamber 309 also applies a force against the outside of the vessel 302 pushing it forward as the jet propulsion force is also thrusting the vessel 302 forward. Accordingly, the presence of the ring 366 aides in the rotation of the vessel 302.

[0073] Preferably, the main shaft 326 is machined within a metal lathe to allow sufficient tolerance for proper mounting of the bearings 311, seals 313, and Vee packing 315. The Vee packing 315 retains the high pressure working fluid within the shaft 326 and within the turbine housing 352. Double lip seals 313 are used on each side of bearings sets 311 primarily to retain the lubrication, such as grease or oil, on the bearings 311. Grease fittings 317 and 319 are provided to supply lubrication to the bearings 311. Holes 346 are preferably drilled into the shaft sidewall and allow the working fluid to exit the shaft 326 and enter the vessel 302.

[0074] The high pressure working fluid is retained within the shaft 326 by a stationary mandrel 397 attached to the turbine housing 352. The mandrel 397 extends into the center of the shaft 326, and the shaft 326 rotates about the mandrel 397. Vee packing 321 is positioned between the outside of the mandrel 397 and an inside of the shaft 326 with the open face of the"V"shape facing forward to intercept the high pressure working fluid. The"V"shape of the Vee packing 321 expands as the working fluid applies a force against the open face of the"V", thereby sealing off the high pressure working fluid to prevent the escape of the working fluid from the shaft.

[0075] The mandrel 397 also has a bearing set 323 positioned between the outside of the mandrel 397 and the inside of the shaft 326 for maintaining precise alignment between the mandrel 397 and the shaft 326. Maintaining this precise alignment prevents wear damage to the Vee packing 321 from wobble caused by misalignment.

[0076] Both the alignment bearings 323 and the left side main shaft bearings 385 are lubricated via grease fitting 319 which supplies oil or grease

lubricant to the bearing sets. A grease fitting 317 supplies lubrication for the right side main shaft bearing 325. The grease fitting 317 also supplies lubrication for the bearing sets 383 located between the outside of the main shaft 326 and the ring shaft 382. A hole located in the ring shaft 382 allows the lubrication to flow through the ring shaft 382 to the bearings sets 383.

[0077] A flanged threaded female nipple 398 is bolted to the mandrel 397. The nipple 398 allows attachment of a working fluid supply line (not shown) via a male fitting (not shown). When attached to the nipple 398, the working fluid supply line supplies high pressure working fluid which flows through the mandrel 397.

[0078] The inside diameter of the mandrel 397 decreases in the direction of flow of the working fluid, thus forming a generally conical shape. At its distal end 333, the inside diameter of the mandrel 397 is smaller than the shaft's inside diameter such that the high pressure working fluid as it exits the mandrel 397 and enters the shaft 326 creates a Venturi effect, causing low pressure to form outside of the mandrel 397. The Venturi effect is advantageous in that it aides to reduce the amount of pressure that must be retained by the Vee packing 321. In some instances, the turbine may accommodate high pressures of perhaps ten thousand pounds per square inch, in which case, the Venturi effect is beneficial to pressure management.

[0079] A cone 335 is provided inside the shaft 326 to direct the flow of working fluid through the shaft's fluid passage 336 to the holes 346 in the shaft sidewall. Providing the cone 335 in the shaft 326 also reduces the possible hammer effect that working fluids can have upon the shaft 326 and turbine 300.

This can be especially advantageous when dual phase working fluids are used in the turbine 300 because dual phase working fluids have a greater potential to "hammer"into the capped end of the shaft 326 due to the greater mass associated with liquid phase working fluids that may be pressurized by high pressure vapor within the working fluid.

[0080] FIG. 7 is an upper cross-sectional view of a turbine having a rotatable vessel 402 and a shaft 426 according to another embodiment of the invention. As shown, the vessel 402 and the shaft 426 are coupled to one another for common rotation via keyway pins 429 engaged with keyways 428

defined in the shaft 426. The vessel 402 includes a plurality of outlets 404 for discharging pressurized working fluid 406 from the vessel 402 to a lower pressure area to produce jet propulsion for rotating the vessel 402. Spacers 479 are provided within the vessel 402 to help direct the flow of the pressurized working fluid within the vessel 402 towards the outlets 404.

[0081] In another embodiment, the working fluid used in the turbine <BR> <BR> comprises a cryogenic working fluid (e. g. , a cryogen, cryogenic vapor or combination thereof). The cryogenic working fluid can be used to not only produce the jet propulsion force for rotating the vessel to rotate and to produce the forces for counter-rotating the ring, but the cryogenic working fluid can also be used to maintain superconducting materials in the stator and rotor at superconducting temperatures.

[0082] The cryogenic working fluid expands as it exits the vessel and enters the lower pressure area. This expansion further reduces the temperature of the cryogenic working fluid. The cryogenic working fluid is then allowed to flow around and through fluid passages within the stator and rotor to provide cooling through heat exchange. Thus, superconducting materials in the stator and rotor are maintained at superconducting temperatures.

[0083] In any of the aforementioned embodiments of the turbine 100, 200, and 300, the working fluid may be either gaseous, liquid, or dual phase. The working fluid may also include solid particulates therein such as debris. Further, the turbine 100,200, and 300 may be operated while submerged within a liquid, such as water.

[0084] In another form, the invention provides methods of operating a turbine having a vessel. In one embodiment, the method generally includes discharging a pressurized working fluid from the vessel to a lower pressure area <BR> <BR> (i. e. , an area having a pressure lower than the pressurized working fluid within the vessel). The discharging of the pressurized working fluid produces jet propulsion for rotating the vessel. In at least one embodiment, the method further includes supplying a pressurized working fluid to the vessel through a shaft having one or more fluid passages extending therethrough.

[0085] The method can also include discharging the pressurized working fluid from the vessel to a ring positioned generally around the vessel.

The discharged pressurized fluid contacts the ring to rotate the ring in a direction generally opposite to a rotational direction of the vessel. The method can further include discharging pressurized working fluid from an area between the vessel <BR> <BR> and the ring to a lower pressure area (i. e. , an area having a lower pressure than the pressure of the pressurized working fluid within the area between the vessel and the ring) such that this discharging produces jet propulsion for rotating the ring.

[0086] In at least one embodiment, the pressurized working fluid is a cryogenic vapor, and the method also includes discharging the cryogenic vapor from within the vessel to produce the jet propulsion for rotating the vessel. In such an embodiment, the method can further include transferring heat to the cryogenic vapor from at least one of a rotor and a stator. Further, the transferring heat can include maintaining at least one of the rotor and the stator at a superconducting temperature.

[0087] In at least one embodiment, the method also includes <BR> <BR> submerging the turbine in a liquid (e. g. , water) and operating the turbine while the turbine is submerged in the liquid.

[0088] Turbines of the present invention can be used in a wide range of applications to output electrical and/or mechanical power. By way of example, one exemplary application employs a turbine of the present invention to harness the kinetic energy of natural gas in interstate to city gate pipeline pressure drops, for example, to produce work. Another exemplary application utilizes a turbine of the present invention in a hydro-electric application in which the turbine is coupled to a generator to drive the generator to produce electricity. Another exemplary application uses a turbine of the present invention in a Rankine cycle of a clean energy generation system in which the energy of heat is used to <BR> <BR> vaporize a low boiling point working fluid (e. g. , propane, refrigerant, etc. ) to generate gas pressure that powers the turbine. Other exemplary applications of a turbine according to the present invention are described in U. S. Provisional Patent Application No. 60/400,870, filed August 5,2002, and U. S. Provisional Patent Application No. 60/410,441, filed September 16,2002, the entire disclosures of which are incorporated herein by reference.

[0089] While various preferred embodiments have been described, those skilled in the art will recognize modifications or variations which might be made without departing from the inventive concept. The examples illustrate the invention and are not intended to limit it. Therefore, the description and claims should be interpreted liberally with only such limitation as is necessary in view of the pertinent prior art.