Abstract: A heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a compressor with a gas bearing supplied with compressed gas and a controller. The controller is configured to determine an inlet pressure and outlet pressure of the gas bearing, determine a maximum speed limit based on the inlet pressure and the outlet pressure, and prevent the compressor from operating at a speed that is greater than the maximum speed limit A method of controlling a compressor includes calculating a maximum speed limit based on an inlet pressure and an outlet pressure of the gas bearing. The method also includes in response to determining that a speed setting is greater than the maximum speed limit, adjusting operation of the compressor such that a speed of the compressor is at or below the maximum speed limit.

Abstract: A compressor includes a bore, a rotor disposed within the bore, a compressor inlet, a compressor outlet and a compression chamber defined between the bore and the rotor. A volume of the compression chamber gradually reduces from the compressor inlet to the compressor outlet. An economizer is configured to fluidically connect to the compression chamber. The economizer is configured to inject a working fluid into the compression chamber at an injection position. The injection position is changeable according to a working condition of the compressor.

Abstract: A lineal product includes a composite pultruded substrate having a solid outer surface, and a multi-layer coating extruded directly onto the outer surface. The coating comprises a solid extruded base layer comprising a first thermoplastic material extruded onto the outer surface, the base layer having a base-layer inner surface in intimate contact with the outer surface and a base-layer outer interface. The coating further comprises a solid extruded outer layer comprising a second thermoplastic material comprising polymethyl methacrylate extruded onto the first thermoplastic material, the solid extruded outer layer having an outer-layer interface in intimate contact with the base-layer outer interface and an outer-layer outer surface, wherein the intimate contact between the base-layer outer interface and the outer-layer interface forms a solid interface between the base layer and the outer layer. The solid extruded outer layer has a hardness of at least 1H pencil hardness.

Abstract: A method is described for operating a refrigerant circuit that includes a compressor with a driveshaft and one or more gas bearings for supporting the driveshaft. The method includes operating the refrigerant circuit in a first mode which includes supplying gaseous working fluid compressed by the compressor to the one or more gas bearings of the compressor, and the one or more gas bearings using the compressed gaseous working fluid to support the driveshaft. The method includes operating the refrigerant circuit in a second mode which includes supplying liquid working fluid to the one or more gas bearings of the compressor, and the one or more gas bearings using the liquid working fluid to support the driveshaft. A refrigerant circuit includes a compressor, a condenser, an expander, an evaporator, and a controller configured to selectively operate the refrigerant circuit in a least a first mode and a second mode.

Abstract: Disclosed is a hermetic AC electric motor that includes harmonics shunting such that high frequency harmonics are shunted from the AC electric motor without the use of one or more high frequency filters in the associated motor drive. A related method of operating an AC electric motor includes shunting high frequency harmonics to a fluid passing through the AC electric motor. Also disclosed is a simplified variable speed motor drive system which eliminates the need for a filter for removing high frequency harmonics.

Abstract: A compressor includes a housing, a shaft that is rotated relative to the housing to compress a working fluid, and a foil bearing that supports the shaft. The foil bearing includes a top foil. The foil bearing is a foil gas bearing that is backed up by a ball bearing, or a mesh foil bearing with an actuator to compress a wire mesh dampener. A heat transfer circuit includes a compressor and a working fluid. The compressor includes a shaft that is rotated to compress the working fluid, and a foil bearing for supporting the shaft as it rotates.

Abstract: A porous gas bearing is disclosed. The porous gas bearing includes a housing having a fluid inlet and an aperture. A porous surface layer is disposed within the housing surrounding the aperture in a circumferential direction. The porous surface layer is in fluid communication with the fluid inlet. A damping system includes a damping system including a biasing member, the biasing member being disposed in a passageway that extends along the longitudinal direction of the aperture and circumferentially about the aperture, wherein the biasing member is arranged radially outward from the porous surface layer.

Abstract: A heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a compressor with a gas bearing supplied with compressed gas and a controller. The controller is configured to determine an inlet pressure and outlet pressure of the gas bearing, determine a maximum speed limit based on the inlet pressure and the outlet pressure, and prevent the compressor from operating at a speed that is greater than the maximum speed limit. A method of controlling a compressor includes calculating a maximum speed limit based on an inlet pressure and an outlet pressure of the gas bearing. The method also includes in response to determining that a speed setting is greater than the maximum speed limit, adjusting operation of the compressor such that a speed of the compressor is at or below the maximum speed limit.

Abstract: Systems and methods are used to control operation of a rotary compressor of a refrigeration system to improve efficiency by varying the volume ratio and the speed of the compressor in response to current operating and load conditions. The volume of the axial and/or radial discharge ports of the compressor can be varied to provide a volume ratio corresponding to operating conditions. In addition, permanent magnet motors and/or control of rotor tip speed can be employed for further efficiency gains.

Abstract: A porous gas bearing is disclosed. The porous gas bearing includes a housing having a fluid inlet and an aperture. A porous surface layer is disposed within the housing surrounding the aperture in a circumferential direction. The porous surface layer is in fluid communication with the fluid inlet. A damping system includes a damping system including a biasing member, the biasing member being disposed in a passageway that extends along the longitudinal direction of the aperture and circumferentially about the aperture, wherein the biasing member is arranged radially outward from the porous surface layer.

Abstract: Methods are directed towards dynamically determining refrigerant film thickness at the rolling-element bearing and for dynamically controlling refrigerant film thickness at the rolling-element bearing. Further, an oil free chiller system is configured for dynamically determining refrigerant film thickness at the rolling-element bearing of the oil free chiller system, wherein the oil free chiller system is also configured for dynamically controlling refrigerant film thickness at the rolling-element bearing of the oil free chiller system.

Abstract: A heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a compressor with a gas bearing supplied with compressed gas and a controller. The controller is configured to determine an inlet pressure and outlet pressure of the gas bearing, determine a maximum speed limit based on the inlet pressure and the outlet pressure, and prevent the compressor from operating at a speed that is greater than the maximum speed limit. A method of controlling a compressor includes calculating a maximum speed limit based on an inlet pressure and an outlet pressure of the gas bearing. The method also includes in response to determining that a speed setting is greater than the maximum speed limit, adjusting operation of the compressor such that a speed of the compressor is at or below the maximum speed limit.

Abstract: A compressor includes a housing, a shaft that is rotated relative to the housing to compress a working fluid, and a foil bearing that supports the shaft. The foil bearing includes a top foil. The foil bearing is a foil gas bearing that is backed up by a ball bearing, or a mesh foil bearing with an actuator to compress a wire mesh dampener. A heat transfer circuit includes a compressor and a working fluid. The compressor includes a shaft that is rotated to compress the working fluid, and a foil bearing for supporting the shaft as it rotates.

Abstract: A heat transfer circuit that includes a compressor with a gas bearing, a condenser, an expander, an evaporator, a lubricant stream, and a heat source. The lubricant stream receives a portion of the working fluid and supplies the portion of the working fluid to the gas bearing of the compressor. A method of supplying lubricant to a gas bearing of a compressor in a heat transfer circuit includes compressing and further heating at least a portion of the working fluid heated in the evaporator, and supplying the compressed and further heated working fluid to the gas bearing of the compressor. A method of the supplying lubricant to a gas bearing of a compressor in a heat circuit includes generating compressed gaseous working fluid within a lubricant stream.

Abstract: A scroll compressor includes a first scroll member, a second scroll member, and an aerostatic thrust bearing. The aerostatic thrust bearing forms a layer of gas between the second scroll member and a fixed supporting member to support the second scroll member as the second scroll member rotates and/or orbits. Also disclosed is a method of supporting a rotating/orbiting scroll member in a scroll compressor. The method including supplying pressurized gas to an aerostatic thrust bearing such that a layer of gas is formed between the rotating/orbiting scroll member and a fixed supporting member.

Abstract: A compressor includes a housing, a shaft that is rotated relative to the housing to compress a working fluid, and a foil bearing that supports the shaft. The foil bearing includes a top foil. The foil bearing is a foil gas bearing that is backed up by a ball bearing, or a mesh foil bearing with an actuator to compress a wire mesh dampener. A heat transfer circuit includes a compressor and a working fluid. The compressor includes a shaft that is rotated to compress the working fluid, and a foil bearing for supporting the shaft as it rotates.

Abstract: A porous gas bearing is disclosed. The porous gas bearing includes a housing having a fluid inlet and an aperture. A porous surface layer is disposed within the housing surrounding the aperture in a circumferential direction. The porous surface layer is in fluid communication with the fluid inlet. A damping system includes a damping system including a biasing member, the biasing member being disposed in a passageway that extends along the longitudinal direction of the aperture and circumferentially about the aperture, wherein the biasing member is arranged radially outward from the porous surface layer.

Abstract: A scroll compressor includes a first scroll member, a second scroll member, and an aerostatic thrust bearing. The aerostatic thrust bearing forms a layer of gas between the second scroll member and a fixed supporting member to support the second scroll member as the second scroll member rotates and/or orbits. Also disclosed is a method of supporting a rotating/orbiting scroll member in a scroll compressor. The method including supplying pressurized gas to an aerostatic thrust bearing such that a layer of gas is formed between the rotating/orbiting scroll member and a fixed supporting member.

Abstract: Methods are directed towards dynamically determining refrigerant film thickness at the rolling-element bearing and for dynamically controlling refrigerant film thickness at the rolling-element bearing. Further, an oil free chiller system is configured for dynamically determining refrigerant film thickness at the rolling-element bearing of the oil free chiller system, wherein the oil free chiller system is also configured for dynamically controlling refrigerant film thickness at the rolling-element bearing of the oil free chiller system.

Abstract: Methods are directed towards dynamically determining refrigerant film thickness at the rolling-element bearing and for dynamically controlling refrigerant film thickness at the rolling-element bearing. Further, an oil free chiller system is configured for dynamically determining refrigerant film thickness at the rolling-element bearing of the oil free chiller system, wherein the oil free chiller system is also configured for dynamically controlling refrigerant film thickness at the rolling-element bearing of the oil free chiller system.