A turbo compressor includes a housing with a refrigerant suction hole, through which a refrigerant is introduced, at a front portion thereof, and a motor case defining an accommodation space. The accommodation space includes a rotation shaft extending in a front-rear direction and a motor that is configured to rotate the rotation shaft. A first impeller is coupled to one end of the rotation shaft and a second impeller is coupled to the other end of the rotation shaft. The first impeller is configured to primarily compress the refrigerant introduced into the refrigerant suction hole. A connection passage, that surrounds the motor case extends backward from an outlet of the first impeller. The second impeller is configured to secondarily compress the refrigerant introduced through the connection passage.

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 heat transfer circuit includes a compressor, a condenser, an expander, and an evaporator that are fluidly connected together. The compressor includes a housing and a shaft rotatable relative to the housing to compress a working fluid received at a suction inlet, in which the shaft is supported by a gas bearing, and the gas bearing including a bearing housing having a fluid inlet and an outlet. A high pressure gas source is fluidly connected to the fluid inlet of the bearing housing for supplying high pressure fluid to the fluid inlet of the gas bearing such that the gas bearing supports the shaft when the shaft is rotating. A pressure reducer is connected to the outlet of the gas bearing is provided for reducing a vent pressure of the gas bearing.

A compressor system includes: a first compressor including a first casing having a cylindrical shape, and a first bundle capable of being inserted into and pulled out from the first casing in an axial direction of the first casing; and a second compressor including a second casing having a cylindrical shape, and a second bundle capable of being inserted into and pulled out from the second casing in an axial direction of the second casing. The first and second compressors are arranged to face each other to cause pullout directions of the respective bundles to be opposite to each other. A maintenance space shareable for insertion and pullout operations of the first bundle and insertion and pullout operations of the second bundle is interposed between the first bundle and the second bundle, and is available for the bundle under the insertion and pullout operations.

In some aspects, the techniques described herein relate to a refrigerant compressor, including: a stator; a rotor configured to rotate with respect to the stator; and at least one step seal between the rotor and the stator, wherein the step seal includes a first tooth and a second tooth extending from the rotor toward the stator, wherein a downstream surface of the first tooth and an upstream surface of the second tooth are arranged at an angle relative to one another, wherein the angle is less than 90°.

A rotor hanging tool includes a beam extending in parallel to an axial direction above a rotor main body, a pair of ring support portions disposed at an interval in the axial direction, connected to the beam, and attachable to and detachable from a support ring, a pair of rotor support portions disposed at an interval in the axial direction, connected to the beam, attachable to and detachable from the rotor main body at positions different from the ring support portions in the axial direction, and respectively supporting the rotor main body from below, and a vertical position adjustment unit for adjusting a position of each of the rotor support portions in a vertical direction with respect to the beam.

The bearing arrangement includes a one-piece gas bearing sleeve (32) configured to rotatably support the drive shaft (4) and made in molybdenum or in a molybdenum alloy, the one-piece gas bearing sleeve (32) including a radial bearing surface (33) configured to Surround the drive shaft (4).

A centrifugal compressor includes: an impeller which is allowed to rotate around an axis; a casing which is provided with a return flow path allowing a fluid pressure-fed from the impeller to flow therein; and a return vane which is disposed inside the return flow path, wherein the return vane is provided with an injection port through which a liquid supplied from the outside is injected to the return flow path. Accordingly, power is further reduced while suppressing pressure loss.

A return geometry fluidically connects a first and a second compressor stage of the turbocompressor. The return geometry has multiple partial helices that are evenly or unevenly distributed in the circumferential direction. The multiple partial helices extend at least in part in the circumferential direction. They form flow channels that extend at least in some sections, separately from each other, to fluidically connect the first and second compressor stages.

A cooling device includes a cooler disposed inside a shell main body formed in a cylindrical shape, and having a first surface facing an inlet nozzle and an outlet nozzle, and a partition member fixed to the first surface, and partitioning a portion between the cooler and an inner peripheral surface of the shell main body into a first space communicating with the inlet nozzle and a second space communicating with the outlet nozzle. The partition member includes a main partition plate disposed between the inlet nozzle and the outlet nozzle in an axial direction, a first guide portion extending from an end portion of the main partition plate toward a first end surface of the shell main body, and a second guide portion extending from an end portion of the main partition plate toward a second end surface of the shell main body.