A centrifugal compressor for a chiller system includes a casing, an inlet guide vane, an impeller disposed downstream of the inlet guide vane, a motor and a diffuser. The casing has inlet and outlet portions with the inlet guide vane disposed in the inlet portion. The impeller is attached to a shaft rotatable about a rotation axis, and the motor rotates the shaft in order to rotate the impeller. The centrifugal compressor further includes a casing treatment bypass having an entrance port and an exit port. The casing treatment bypass injects refrigerant from a gap between the impeller and the inlet portion of the casing toward an area between the impeller and the inlet guide vane. The exit port of the casing treatment bypass is positioned upstream in a direction of a refrigerant flow with respect to the entrance port of the casing treatment bypass.

A stator is a stator disposed outside a rotor of a motor disposed in a compressor used with a refrigerant containing a substance having a property of causing disproportionation. The stator includes a yoke part and N tooth parts. Each of the N tooth parts includes a tooth end surface to face a rotor. The stator satisfies 0.75≤(θ1×N)/360≤0.97, where θ1 (degrees) is an angle famed by two lines passing through both ends of the tooth end surface and a rotation center of the rotor in a plane perpendicular to an axial direction of the rotor.

An electric motor system is described. The electric motor system includes a drive circuit including an inverter configured to supply variable frequency current and a contactor configured to supply line frequency current. The electric motor system also includes an electric motor coupled to the drive circuit wherein the electric motor is communicatively coupled to a controller. The controller is configured to control the inverter to supply variable frequency current to the electric motor, thereby operating the electric motor at a motor speed, and determine, based upon at least one input parameter, a maximum potential motor speed the inverter can achieve. The controller is also configured to receive a command to operate the electric motor at line frequency current and control the drive circuit to transition from supplying variably frequency current to supplying line frequency current before the maximum potential motor speed the inverter can achieve is reached.

A refrigeration system includes a rotary pressure exchanger fluidly coupled to a low pressure loop and a high pressure loop. The rotary pressure exchanger replaces a traditional bulk flow compressor. The rotary pressure exchanger is configured to receive the refrigerant at high pressure from the high pressure loop, to receive the refrigerant at low pressure from the low pressure loop, and to exchange pressure between the refrigerant at high pressure and the refrigerant at low pressure, and wherein a first exiting stream from the rotary pressure exchanger includes the refrigerant at high pressure in the supercritical state or the subcritical state and a second exiting stream from the rotary pressure exchanger includes the refrigerant at low pressure in the liquid state or the two-phase mixture of liquid and vapor.

A rotor includes a rotor core having magnet insertion holes in a number corresponding to a pole number, and a center hole. The rotor core has first slits and ribs alternately arranged in the circumferential direction along a periphery of the center hole, and second slits on an outer side with respect to the first slits in the radial direction. The first slits and the second slits are both equal in number to half or an integer multiple of the pole number. Each second slit is formed to cover the rib from an outer side in the radial direction. Each first slit has a length A1 in the circumferential direction and a width A2 in the radial direction. Each second slit has a length B1 in the circumferential direction and a width B2 in the radial direction. A1>A2, B1>B2, and A1>B1 are satisfied.

The present disclosure provides a compressor rotor, a compressor and a refrigerant circulation system. The compressor rotor includes: a motor rotor including a plurality of rotor sections, a locking rod, a compression unit rotating part and a locking member. The rotor sections are fixedly connected in an axial direction and are provided with an axial through hole; and the locking rod penetrates through the axial through hole. The compression unit rotating part is located at the end part of the motor rotor and is connected to the locking rod. The locking member is configured to lock the compression unit rotating part on the locking rod. The locking rod, the compression unit rotating part and the locking member form a pressing structure which applies a pressure toward an axial inner side to the motor rotor.

A compressor assembly, a vapor compression system incorporating the same, and a method for operating the vapor compression system are provided. The compressor assembly includes a motor for driving a rotating shaft, a foil bearing for supporting the rotating shaft, a compression mechanism for increasing the pressure of a working fluid, a supply line in fluid communication with the compression mechanism, and a heating apparatus for heating the working fluid. The supply line is configured for injecting the working fluid (e.g., from downstream of the compression mechanism) toward the foil bearing. The method provides for the monitoring of the temperature of the working fluid. When the temperature of the working fluid is less than 3° F. of superheat it is heated prior to being injected toward the foil bearing. The heating of the working fluid prevents, or at least mitigates, liquid from being transferred to the foil bearing.

An electric motor includes a stator, and a rotor having a plurality of magnetic poles. Each magnetic pole includes a rotor core having through holes arranged circumferentially side by side, and a permanent magnet inserted into each through hole. A length of a portion of the rotor core in a radial direction of the rotor is shorter than a length of the permanent magnet in the radial direction of the rotor. The length of the portion of the rotor core is measured between an inner surface of each of the through holes adjacent to an outer periphery of the rotor and an outer peripheral surface of the rotor. The permanent magnets generate a magnetic flux in a magnetic circuit showing a smaller magnetic resistance in a portion of the rotor radially outward of the permanent magnets than in a portion of the rotor radially inward of the permanent magnets.

The present invention includes: an electric component; a compression component driven by the electric component; and a sealed container accommodating the electric component and the compression component. The compression component includes: a shaft part rotated by the electric component; and a bearing part slidingly contacting the shaft part. A film having hardness equal to or more than hardness of a sliding surface of the bearing part is provided on a sliding surface of the shaft part. The sliding surface of the bearing part includes a curved-surface portion having an inner diameter that continuously increases, or the sliding surface of the shaft part includes a curved-surface portion having an outer diameter that continuously decreases.

A compressor may include a shell, a first scroll, and a second scroll. The shell may include a first inlet, a second inlet, and an outlet. The first scroll may include a first end plate and a first spiral wrap. The second scroll may include a second end plate and a second spiral wrap, the first and second spiral wraps cooperating to define a series of moving compression pockets therebetween. The moving compression pockets decrease in volume as the moving compression pockets move from a radially outer position to a radially inner position. The moving compression pockets may receive working fluid from the first inlet at the radially outer position and provide working fluid to the outlet at the radially inner position. The second end plate may include a fluid cavity receiving working fluid from the second inlet and fluidly isolated from working fluid within the moving compression pockets.