Abstract: A system for using a generator to simultaneously power a variable frequency motor drive locally and provide clean power to a grid comprising an electric generator supplying alternating current to a power conversion system. The power conversion system includes a converter changing generator AC output to direct current (DC); a capacitor bank that filters the DC from the converter and outputs a DC bus power; a grid inverter capable of replicating grid power from the DC bus power; and an output filter for supplying power to the power grid. A variable frequency motor drive receives DC bus power from the power conversion system. The variable frequency motor drive may be operatively connected to the power conversion system, or integrated therein.

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: 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: The present invention provides an improved design for turbomachinery, such as blowers and compressors, for providing pressurized process gas. The improved design comprises two housing portions that fit together to form an interior cavity in which a preassembled rotating assembly may be installed and balanced. Each housing portion includes an interior compartment designed and shaped to correspond to desired positions of components of the rotating assembly. After the preassembled rotating assembly is seated within the interior compartment of the lower housing portion and balanced, the upper housing portion can be fitted to the lower housing portion to complete the machine housing and encompass and hold the rotating assembly in place without the need to remove or disassemble the rotating assembly. A collector cover can thereafter be attached to the assembled machine housing to enclose an impeller operatively mounted on a rotating shaft of the rotating assembly.

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.

Abstract: A two-stage compressor for generating necessary pressure differential for air-conditioning applications with air-cooled, water-cooled and evaporative-cooled condensing systems using low-pressure refrigerant, such as R134a, is provided. A rotating assembly is mounted for rotation in a compressor housing and includes a shaft, a thrust bearing disk associated with the shaft to maintain an axial position of the rotating assembly, a motor rotor mounted on the shaft, and first and second impellers mounted for rotation with the shaft. First and second journal bearings are mounted in the compressor housing to support the shaft and maintain radial positioning of the rotating assembly. Volute housings including a spiral-shaped volute are associated with each of the impellers to collect and further discharge gas compressed by the impellers. Diffusers having air-foil shaped vanes are locate in the volute channels adjacent the discharge outlets of the impellers to aide in the discharge of gas from the impellers.

Abstract: A stacked foil thrust bearing assembly provides a compact, lightweight, high load capacity, high temperature, oil-free foil thrust bearing for use in high speed rotating machinery. A stacked foil thrust bearing assembly comprises a plurality of thrust runners in adjacently spaced and parallel relationship. Each thrust runner includes an annular-shaped portion having generally opposite axial sides, and a thrust bearing positioned on each of the generally opposite axial sides. Each thrust bearing includes a thrust bearing plate and a spring plate operatively engaging the thrust bearing plate. A plurality of foils are circumaxially dispersed about one axial side of the thrust bearing plates. A plurality of springs are circumaxially dispersed about one axial side of the spring bearing plates.

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: A two-stage compressor for generating necessary pressure differential for air-conditioning applications with air-cooled, water-cooled and evaporative-cooled condensing systems using low-pressure refrigerant, such as R134a, is provided. A rotating assembly is mounted for rotation in a compressor housing and includes a shaft, a thrust bearing disk associated with the shaft to maintain an axial position of the rotating assembly, a motor rotor mounted on the shaft, and first and second impellers mounted for rotation with the shaft. First and second journal bearings are mounted in the compressor housing to support the shaft and maintain radial positioning of the rotating assembly. Volute housings including a spiral-shaped volute are associated with each of the impellers to collect and further discharge gas compressed by the impellers. Diffusers having air-foil shaped vanes are locate in the volute channels adjacent the discharge outlets of the impellers to aide in the discharge of gas from the impellers.

Abstract: The present invention provides a compliant foil thrust bearing that will remain parallel and compliant to a thrust runner operatively coupled to a rotating shaft of high speed rotating machinery over a broad range of size and operating environments and loads. The thrust bearing comprises a thrust bearing plate including a plurality of decoupled bearing segments, and a spring plate operatively engaging the thrust bearing plate, the spring plate including a plurality of decoupled spring plate segments. The respective decoupled segments are defined in part by a plurality of line of weakness, such as slits, slots, perforations, etched lines and grooves, circumaxially dispersed about the thrust bearing plate and the spring plate. A plurality of compliant foils are disposed on the surface of the thrust bearing plate, and a plurality of springs are disposed on the surface of the spring plate to improve the compliancy of the thrust bearing.

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.

Abstract: A plurality of variable speed centrifugal compressors operated in parallel form an HVAC or refrigeration system. The compressors are operated at proportionally synchronized speeds throughout their range of operation.

Abstract: A hydrodynamic fluid film bearing has a stationary retaining member (12) having a cylindrical opening (14) to receive for rotation therein a rotatable shaft (16). The inner surface (20) of the opening (14) is lined by a generally cylindrical-shaped foil assembly (18) comprised of a plurality of foil sub-assemblies (24) each comprised of spring foils (26), contact foils (30) and, optionally, inner foils (32). Each foil sub-assembly (24) subtends a rotational segment, less than all, of the inner surface (20), e.g., from about 45 degrees to 120 degrees of rotation. The spring foils (26) and contact foils (30) are affixed to the retaining member (12) in such a way that sliding travel of the spring foils (26) along the inner surface (20) is in the opposite rotational direction of sliding travel of the contact foils (30) along the inner surface (20). The foil sub-assemblies (24) may be affixed to the retaining member (12) by means of keyways (22a-22e) within which the foil sub-assemblies (24) are mounted.

Abstract: A fixed shape hydrodynamic journal bearing 10 is provided having a plurality of pads 18, each pad having a peak 22, a trough 20, and a curve 24 connecting the peak and the trough, the curve being defined by the equation: h=r+s (1-.theta..sub.1 /.theta..sub.2).sup..alpha..

Abstract: A hydrodynamic fluid film thrust bearing including a stationary thrust plate 15, a rotating thrust runner 20 spaced therefrom, and at least one foil 50 disposed therebetween, is provided with first and second sets 25 and 45 of overlying resilient backing members in axial alignment with the foil. One of the backing members 25, having a lower relative spring constant, provides the bearing with compliance for adequate load capacity and damping characteristics. The other backing member 45, having a higher relative spring constant, establishes and maintains an optimum fluid film geometry under all loading, speed and other operating conditions.

Abstract: A hydrodynamic fluid film journal bearing comprises a stationary retaining member 15, a rotatable journal 20 disposed therewithin and an insert comprising a smooth cylindrical foil element 25 and a corrugated, cylindrical, resilient backing member 45 disposed radially outwardly from the foil. The foil element and the resilient backing member are fixed at ends thereof to the retaining member such that the backing member extends from the fixed end, in an opposite circumferential direction from that of the extension of the foil element from the fixed end thereof. The journal is supported by a fluid film layer maintained by relative rotary motion between the journal and the foil element, the backing accommodating deflections of the foil and excursions of the journal due to fluid pressure and loading of the bearing.