Abstract: A cryogenic oil-free direct drive turbogenerator for gas liquefaction plant applications is described. The pressure energy from cryogenic gas is expanded through a turbine and the power generated is converted into electricity through a directly driven generator and a power electronics arrangement. The machinery can withstand very cold temperature operation (e.g., <?425° F.) by isolating the cold turbine side from the warmer side of the machine turbine end and has a hermetically sealed design wherein the process gas is fully contained from leaking at operating pressures. A unique gas injection scheme uses seal gas segregation, thrust bearing cooling and pressure balance for thrust control which is accomplished through a pressure regulator arrangement. Also described is an algorithm for speed control and overspeed protection through the power electronics system. The rotating components of the turbogenerator are supported on foil gas bearings for oil-free operation eliminating extraneous lubrication.

Abstract: An electric motor includes a stator; an annular end cap, fastened at a first end of the stator; a threaded seat that is mounted at an outward end face of the annular end cap for receiving a first gas foil thrust bearing; a shaft, inserted through the stator, through the annular end cap, and through the threaded seat; a thrust runner mounted at an end of said shaft adjacent the threaded seat; a first gas foil thrust bearing that is mounted into the threaded seat, adjacent a face of the thrust runner facing the stator; a bearing cap that has a threaded fitting by which it is attached onto the threaded seat; and a second gas foil thrust bearing that is mounted into the bearing cap adjacent to a face of the thrust runner opposite the first gas foil thrust bearing.

Abstract: An electric motor includes a stator; an annular end cap, fastened at a first end of the stator; a threaded seat that is mounted at an outward end face of the annular end cap for receiving a first gas foil thrust bearing; a shaft, inserted through the stator, through the annular end cap, and through the threaded seat; a thrust runner mounted at an end of said shaft adjacent the threaded seat; a first gas foil thrust bearing that is mounted into the threaded seat, adjacent a face of the thrust runner facing the stator; a bearing cap that has a threaded fitting by which it is attached onto the threaded seat; and a second gas foil thrust bearing that is mounted into the bearing cap adjacent to a face of the thrust runner opposite the first gas foil thrust bearing.

Abstract: A high-speed, single-stage, motor-driven blower designed to move water vapor includes an axial flow compressor and a rotating assembly supported by gas foil bearings and driven by a brushless permanent magnet synchronous motor utilizing a remotely mounted variable frequency drive. The blower is immersed in a water vapor flow for operation. Accordingly, the blower comprises an outer blower housing and an inner blower housing defining an annular cavity therebetween, wherein the inner blower housing is held within the outer blower housing by seals, and contains and protects the motor components and the bearings against water damage and contamination. A cooling flow may be leaked through the inner blower housing to cool the internal operational components of the blower and to capture heat therefrom, which can be added to the water vapor flow moving through the blower.

Abstract: An electric motor stator includes an armature surrounding a longitudinal opening for receiving a shaft, with longitudinal fins protruding from an outer surface of said armature; windings are wound within the armature and protruding beyond ends of the armature; and encapsulant seals the windings to the armature, such that the encapsulant serves as an outer housing for the windings.

Abstract: An electric motor includes a stator; an annular end cap, fastened at a first end of the stator; a threaded seat that is mounted at an outward end face of the annular end cap for receiving a first gas foil thrust bearing; a shaft, inserted through the stator, through the annular end cap, and through the threaded seat; a thrust runner mounted at an end of said shaft adjacent the threaded seat; a first gas foil thrust bearing that is mounted into the threaded seat, adjacent a face of the thrust runner facing the stator; a bearing cap that has a threaded fitting by which it is attached onto the threaded seat; and a second gas foil thrust bearing that is mounted into the bearing cap adjacent to a face of the thrust runner opposite the first gas foil thrust bearing.

Abstract: A hermetically-sealed turbomachine, such as a motor-driven blower and a turbine driven generator, capable of reliable high-temperature operation, especially for large sized turbomachine includes a hot blower, compressor or turbine end of the turbomachine that is separated from the cooler electric motor, generator or alternator end of the turbomachine by a compliant mechanical coupling and a thermal choke assembly. The turbomachine housing is also hermetically sealed, providing control over the process gas within the machine housing, and permitting an internal cooling method within the turbomachine, whereby a small amount of process gas itself is used within the turbomachine for providing cooling of the rotating shafts, the axial fan, radial fan, or turbine impeller, the bearings and the electric motor, generator or alternator disposed within the turbomachine housing. The cooling method can be aided by a heat exchanger operatively communicating with the turbomachine.

Abstract: An electric motor stator includes an armature surrounding a longitudinal opening for receiving a shaft, with longitudinal fins protruding from an outer surface of said armature; windings are wound within the armature and protruding beyond ends of the armature; and encapsulant seals the windings to the armature, such that the encapsulant serves as an outer housing for the windings.

Abstract: An electric motor includes a stator; an annular end cap, fastened at a first end of the stator; a threaded seat that is mounted at an outward end face of the annular end cap for receiving a first gas foil thrust bearing; a shaft, inserted through the stator, through the annular end cap, and through the threaded seat; a thrust runner mounted at an end of said shaft adjacent the threaded seat; a first gas foil thrust bearing that is mounted into the threaded seat, adjacent a face of the thrust runner facing the stator; a bearing cap that has a threaded fitting by which it is attached onto the threaded seat; and a second gas foil thrust bearing that is mounted into the bearing cap adjacent to a face of the thrust runner opposite the first gas foil thrust bearing.

Abstract: A turbine-driven alternator (i.e., a turbomachine) suitable for generating electrical power from process gas waste energy. In particular suitable for very high density process gases such as super critical CO2, R134a, R245fa, etc. The turboalternator comprises two separate machines, specifically, a turbine device and an alternator device operatively connected together by a coupling shaft. The rotating shaft assemblies for each machines on the turbine side and the alternator side are supported by hydrodynamic foil gas bearings. The foil gas bearings use process gas at the turbine side, enabling high-pressure operation (˜3000 psia) and thrust load balancing. At the alternator side, cooling fluid is used in the foil gas bearings, enabling high-speed (˜40,000 rpm), low-windage, oil-free operation with closed-loop shaft cooling.

Abstract: A turbine-driven alternator (i.e., a turbomachine) suitable for generating electrical power from process gas waste energy. In particular suitable for very high density process gases such as super critical CO2, R134a, R245fa, etc. The turboalternator comprises two separate machines, specifically, a turbine device and an alternator device operatively connected together by a coupling shaft. The rotating shaft assemblies for each machines on the turbine side and the alternator side are supported by hydrodynamic foil gas bearings. The foil gas bearings use process gas at the turbine side, enabling high-pressure operation (˜3000 psia) and thrust load balancing. At the alternator side, cooling fluid is used in the foil gas bearings, enabling high-speed (˜40,000 rpm), low-windage, oil-free operation with closed-loop shaft cooling.

Abstract: This invention provides an advanced position and velocity estimation scheme used in a position-sensorless control system for synchronous operation of an electric motor. The system includes an electric motor having a stator and a rotor; an inverter for powering the electric motor; and a controller for controlling the inverter. The controller utilizes a control system comprising a rotor angle and angular velocity estimation block; an estimated angle error detector block; a field-weakening block; and a torque-to-current converter block, all of which operate to generate control commands for operation of the motor.

Abstract: This invention provides a blower design capable of high temperature operation due to use of a self-sustaining cooling scheme through a sealed motor housing in which a cooling circuit can be created, and the use of a thermal barrier across which a temperature gradient may be formed. The thermal barrier may be formed by a thermal choke plate assembly positioned between a hot side and a cold side of the blower to dissipate heat conducted from the hot side. Alternatively, the thermal barrier may be formed by an internal fan ring provided with the blower's rotating assembly to dissipate heat conducted from the blower's impeller. The thermal choke plate assembly and the fan ring may further be used in combination to block heat transfer by all modes between a hot side and a cold side of the blower.

Abstract: The present invention provides a hermetically sealed turbomachine, such as a motor-driven blower and a turbine driven generator, capable of reliable high-temperature operation, especially for large sized turbomachines. The hot blower, compressor or turbine end of the turbomachine is separated from the cooler electric motor, generator or alternator end of the turbomachine by a compliant mechanical coupling and a thermal choke assembly, providing reliable high-temperature operation. The turbomachine housing is also hermetically sealed, providing control over the process gas within the machine housing, and permitting an internal cooling method within the turbomachine, whereby a small amount of process gas itself is used within the turbomachine for providing cooling of the rotating shafts, the axial fan, radial fan, or turbine impeller, the bearings and the electric motor, generator or alternator disposed within the turbomachine housing.

Abstract: A hydrodynamic fluid film bearing assembly has a stationary retaining member defining a central opening and having an inner surface lined by a foil assembly comprised of a plurality of foil subassemblies. Each foil subassembly comprises a first compliant foil, a second compliant foil, and a spring foil, and subtending a rotational segment, less than all, of the inner surface of the retaining member. The complaint foils and the spring foil of each foil subassembly are held within the retaining member in such a way that sliding travel of one compliant foil along the inner surface of the opening is in the opposite rotational direction of sliding travel of the other compliant foil and the spring foil. The foil subassemblies may be restrained from undesired movement during operation by a retention tab extending from the foil subassembly which engages a channel and recess feature formed in the retaining member.

Abstract: This invention provides a small, high efficiency, oil-free turbine-driven alternator (i.e. turboalternator) suitable for conversion of stored energy in a process gas to electrical power, facilitating recapture of energy during operation that would otherwise be wasted. The turboalternator includes a turbine and a generating device operatively connected together by a rotating shaft capable of rotating at high speeds. The rotating shaft is supported by foil gas bearings.

Abstract: An improved and enhanced dynamic seal for use in high-speed turbomachinery includes an inner ring coupled to an outer sleeve. The coupling between the inner ring and the outer sleeve is strengthened by forming an increased surface area, exhibited by recesses, in at least one of the outer surface of the inner ring and the inner surface of the outer sleeve, and by providing an adhesive material in the recesses to bond the inner ring to the outer sleeve. Additionally, the coupling can be further strengthened by providing complementary projections on at least one of the outer surface of the inner ring and the inner surface of the outer sleeve to fit into the recesses.

Abstract: A foil thrust bearing forms the primary rotating interface for a film riding face seal. This face seal includes a spring system that will allow the entire assembly to translate axially relative to a static attachment. The complete assembly will form a hybrid foil/film riding face seal that shows much promise at being sufficiently flexible to enable operation in a gas turbine engine. The seal includes a flexible top plate having a non-flat surface under its working conditions, and a spring support system to allow the top plate to accommodate axial excursions and out-of-flat distortions.

Abstract: An improved and enhanced hydrodynamic fluid film bearing for rotatably supporting a shaft journal is provided and includes a stationary retaining member, at least two generally cylindrical foil elements attached to one another and forming an anti-rotation fin, and a generally cylindrical resilient backing member. The retaining member has an inner surface defining a cylindrical opening for receiving a shaft journal. The inner surface also includes a longitudinally extending slot in which the anti-rotation fin formed by the foil elements is mounted so that the foil elements line at least a portion of the cylindrical opening. The resilient member is also disposed within the cylindrical opening generally concentric to and radially outward from the foil elements. The foil elements may be discrete elements attached together to form the anti-rotation fin, or alternatively formed from a single foil with a bend defining the anti-rotation fin.

Abstract: This invention provides a small, high efficiency, oil free motor driven compressor/blower suitable for providing pressurized, contamination-free gas and or air to transportation, industrial and aerospace fuel cell systems or other contaminant-intolerant applications. The motor driven compressor/blower rotor assembly is supported by foil air bearings and rotates at high speed by using a high frequency drive. The impeller is a centrifugal type design. The MDC can be easily integrated into the air management system of a fuel cell.