The integrated expander and motor-compressor assembly comprises a compression section mounted between the two radial bearings on a trans-mission shaft, an expander cantilevered at a free end of the transmission shaft, a gas diffuser and a duct between the expander and a first radial bearing, the first radial bearing been the closest radial bearing to the expander. The gas diffuser diffuses a gas barrier which is sucked up by the duct.

The integrated expander and motor-compressor assembly comprises a compression section mounted between the two radial bearings on a trans-mission shaft, an expander cantilevered at a free end of the transmission shaft, a gas diffuser and a duct between the expander and a first radial bearing, the first radial bearing been the closest radial bearing to the expander. The gas diffuser diffuses a gas barrier which is sucked up by the duct.

A thrust gas bearing includes a collar portion fixed to a shaft portion, a first base part facing one axial end surface of the collar portion, a first gas film forming part formed between the collar portion and first base part, a second base part facing an other axial end surface of the collar portion, a second gas film forming part formed between the collar portion and second base part, and a cooling flow path to carry a fluid flow. The cooling flow path includes a first flow path formed on one axial end side of the first base part and extending from an axial center toward an outer periphery, and a second flow path formed on an other axial end side of the second base part and extending from an outer periphery toward an axial center. The second to flow path is located downstream of the first flow path.

Provided is grease capable of suppressing a decrease in a function as a lubricant even when used in a device installed in a refrigerant circuit in which a refrigerant containing a chlorine atom and an olefin bond in a molecule flows, and a refrigeration cycle apparatus using the grease as a lubricant. Grease that is used in a device installed in a refrigerant circuit in which a refrigerant containing a chlorine atom and an olefin bond in a molecule flows contains fluorine as a component. In a chiller apparatus, the grease is used as a lubricant for at least one of a first radial touchdown bearing and a second radial touchdown bearing of a compressor, a drive portion of an inlet guide vane of the compressor, and a drive portion of an expansion valve.

Provided is grease capable of suppressing a decrease in a function as a lubricant even when used in a device installed in a refrigerant circuit in which a refrigerant containing a chlorine atom and an olefin bond in a molecule flows, and a refrigeration cycle apparatus using the grease as a lubricant. Grease that is used in a device installed in a refrigerant circuit in which a refrigerant containing a chlorine atom and an olefin bond in a molecule flows contains fluorine as a component. In a chiller apparatus, the grease is used as a lubricant for at least one of a first radial touchdown bearing and a second radial touchdown bearing of a compressor, a drive portion of an inlet guide vane of the compressor, and a drive portion of an expansion valve.

An air cycle machine includes an air inlet connected to an air cycle compressor. Air downstream of the air cycle compressor is connected to be delivered across a first turbine. The air cycle compressor is driven by the first turbine through a shaft. Air downstream of the first turbine is connected to a second turbine. The second turbine is connected to deliver air downstream. The second turbine is connected with a second shaft to drive a fan rotor. The fan rotor delivers a source of air across a primary heat exchanger positioned between the inlet and the air cycle compressor. The air cycle compressor and the first turbine are formed of a metal. The second turbine and the fan rotor are formed of non-metallic materials.

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.

A method of operating a chiller system includes receiving an input from at least one sensor associated with a compressor of the chiller system, determining that the compressor is experiencing a surge or rotating stall event, adjusting at least one operating parameter associated with a heat rejection heat exchanger of the chiller system in response to determining that the compressor is experiencing the surge or rotating stall event, and reducing a condenser saturation temperature by adjusting the at least one operating parameter.

A method of operating a chiller system includes receiving an input from at least one sensor associated with a compressor of the chiller system, determining that the compressor is experiencing a surge or rotating stall event, adjusting at least one operating parameter associated with a heat rejection heat exchanger of the chiller system in response to determining that the compressor is experiencing the surge or rotating stall event, and reducing a condenser saturation temperature by adjusting the at least one operating parameter.

Provided is a refrigeration machine provided with: a refrigeration cycle having a compressor, a condenser, an expander, an evaporator, and piping (12) which sequentially connects the compressor, the condenser, and the expander; and an acoustic device (13) having a space formation section (14) which has one end (14a) connected to the piping (12) and in which a space is formed, the acoustic device (13) also having a vibration body (20) which is affixed integrally to the other end of the space formation section (14) and which has a lower natural frequency than the space formation section (14).