An electric motor for a vapor compression system is disclosed. The electric motor is provided with a working fluid. The electric motor includes a housing forming cavity therein. The housing includes a rotor, a stator, and a shaft. The rotor is secured to the shaft and the stator surrounds at least a portion of the rotor. An airgap is formed between the rotor and the stator. An inlet of the housing receives the working fluid and is in fluid communication with the airgap. An outlet of the housing is in fluid communication with the airgap and receives the working fluid from the airgap. The electric motor further includes an impeller that induces flow of the working fluid between the inlet and the outlet.

A fluid temperature control system cools a fluid by means of a multiple refrigeration apparatus including a high-temperature-side refrigerator (100), a medium-temperature-side refrigerator (200) and a low-temperature-side refrigerator (300). The medium-temperature-side refrigerator (200) in the multiple refrigeration apparatus has a medium-temperature-side first evaporator (204) and a medium-temperature-side second evaporator (224). A high-temperature-side evaporator (104) of the high-temperature-side refrigerator (100) and a medium-temperature-side condenser (202) of the medium-temperature-side refrigerator (200) constitute a first cascade condenser (CC1). The medium-temperature-side second evaporator (224) of the medium-temperature-side refrigerator (200) and a low-temperature-side condenser (302) of the low-temperature-side refrigerator (300) constitute a second cascade condenser (CC2). The medium-temperature-side refrigerant and the low-temperature-side refrigerant are the same refrigerant. The fluid allowed to flow by a fluid flow apparatus is cooled by the medium-temperature-side first evaporator (204) of the medium-temperature-side refrigerator (200), and is then cooled by the low-temperature-side evaporator (304) of the low-temperature-side refrigerator (300).

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.

A compressor includes: a stator core including a plurality of teeth around which an aluminum winding wire is wound in a concentrated manner; a rotor core disposed on an inner diameter side of the stator core and including a plurality of magnet insertion holes; and a plurality of ferrite magnets inserted in the magnet insertion holes, in which when a width of a winding wire portion formed in each of the teeth is represented as A, a length in an axis direction of the stator core is represented as L, and the number of slots is represented as S, the stator core has a shape that satisfies a relation of 0.3<S×A÷L<2.2.

A compressor includes a compression mechanism, a motor, a drive shaft, and a motor cooler. The compressor is configured to compress a working fluid. The motor dives the compression mechanism and is housed within a motor housing. The drive shaft is engaged with the motor and the compression mechanism and is configured to drive operation of the compression mechanism. The motor cooler is disposed adjacent the motor and is configured to pump a cooling working fluid around the motor. The motor cooler includes a pump that pumps the cooling working fluid into the motor housing based on a rotational speed of the drive shaft.

A refrigeration apparatus, including a main circuit (1) for circulation of a main flow (90) of refrigerant, and a lubrication branch (20), comprising a lubrication inlet (21), configured to derive a lubrication flow (91) from the main flow (90) circulating through a supply part (16) of the main circuit; and a lubrication outlet (22), to feed the compressor (2) with the lubrication flow (91) for lubrication. According to the invention, the refrigeration apparatus further includes: a subcooling branch (40), comprising a subcooling inlet (41), connected to an evaporator (8) of the main circuit (1), so as to derive a subcooling flow (92), and a subcooling outlet (42), connected to the evaporator (8), for reintroducing the subcooling flow (92) into the main flow (90); and a subcooling heat exchanger (31).

A lubricant supply system is for a compressor that compresses a first working fluid in a heat transfer circuit. The lubricant supply system includes a lubricant tank, a lubricant pathway for supplying lubricant from the lubricant tank to one or more bearings of the compressor, and a lubricant refrigeration system with a lubricant heater and a lubricant cooler. The lubricant heater configured to heat the lubricant discharged from the one or more bearings and the lubricant cooler configured to cool the lubricant flowing through the lubricant pathway. A method of lubricating a compressor includes heating the lubricant, directing the lubricant from a lubricant tank through a lubricant pathway to one or more bearings of the compressor, and cooling the lubricant passing through the lubricant pathway.

This disclosure is directed to systems and methods for controlling compressor motors, particularly varying the operation parameters of the motor to provide heat to a lubricant of the motor. The operation parameters include one or more of a pulse width modulation switching frequency, a pulse width modulation frequency switching pattern, or a torque/amp ratio of a drive of the compressor. The efficiency of the motor may be reduced to provide heat, with the heat improving lubricant quality and drive efficiency, to increase an overall efficiency of compressor operations. Methods may include determining a lubricant quality, and determining operational parameters that improve lubricant quality.

A compressor operable in a heat pump mode of a refrigerant circuit includes a compression space in which a refrigerant is compressed. The compression space includes a discharge port and an injection port. A discharge chamber is fluidly coupled to the compression space by the discharge port. An injection chamber is fluidly coupled to the compression space by the injection port. A discharge recirculation pathway selectively provides fluid communication between the discharge chamber and the injection chamber. An injection of the recirculated refrigerant into the compression space through the injection port results in an increase in pressure, and hence temperature, of the refrigerant when discharged to the discharge chamber. The increased temperature of the discharged refrigerant increases a heating capacity of a condenser of the associated refrigerant circuit.

A cooling circuit comprises a refrigerant compressor incorporating a suction port and a pressure chamber incorporating a pressure port, a condenser arranged downstream of the pressure port, a fluid collecting chamber in which a reservoir of refrigerant is formed, an evaporator which is located between the condenser and the suction port, a feed unit which is connected at one side to the refrigerant reservoir and to the pressure chamber at the other side and which serves for supplying refrigerant from the refrigerant reservoir to the pressure chamber which incorporates a pumping unit for the refrigerant. It is proposed that in order improve this cooling circuit, the pumping unit comprise a pressure-tight closed housing which is provided with only one inlet and one outlet as access points and a pumping element which is movable for pumping the refrigerant be arranged in the pumping chamber thereof.