A pump includes a casing defining an interior volume. The pump casing includes at least one balancing plate that can be part of a wall of the pump casing with each balancing plate including a protruding portion having two recesses. Each recess is configured to accept one end of a fluid driver. The balancing plate aligns the fluid displacement members with respect to each other such that the fluid displacement members can pump the fluid when rotated. The balancing plates can include cooling grooves connecting the respective recesses. The cooling grooves ensure that some of the liquid being transferred in the internal volume is directed to bearings disposed in the recesses as the fluid drivers rotate.

A vane rotary compressor may include a main bearing and a sub bearing provided with a plurality of back pressure pockets each having a different pressure formed on a surface facing the cylinder, a rotational shaft radially supported by the main bearing and the sub bearing, a roller provided with a back pressure chamber that communicates with the plurality of back pressure pockets and having a plurality of vanes configured to divide a compression space into a plurality of compression chambers. At least one of the main bearing or the sub bearing is provided with an oil supply passage that communicates with a back pressure pocket having a relatively low pressure among the plurality of back pressure pockets. Accordingly, oil may be smoothly supplied to a back pressure pocket having a low pressure.

A vane rotary compressor may include a main bearing and a sub bearing provided with a plurality of back pressure pockets each having a different pressure formed on a surface facing the cylinder, a rotational shaft radially supported by the main bearing and the sub bearing, a roller provided with a back pressure chamber that communicates with the plurality of back pressure pockets and having a plurality of vanes configured to divide a compression space into a plurality of compression chambers. At least one of the main bearing or the sub bearing is provided with an oil supply passage that communicates with a back pressure pocket having a relatively low pressure among the plurality of back pressure pockets. Accordingly, oil may be smoothly supplied to a back pressure pocket having a low pressure.

A system includes a compressor housing having an intake portion and a discharge portion and a rotor disposed in the compressor housing and configured to compress a fluid flowing from the intake portion toward the discharge portion. The rotor includes a body portion and an internal passageway formed within the body portion extending along an axial length of the rotor. The internal passageway is configured to direct a lubricant between the intake portion and the discharge portion of the compressor housing.

A rotary compressor is provided that may include a cylinder having an inner peripheral surface defined in an annular shape to define a compression space, and provided with a suction port configured to communicate with the compression space and through which refrigerant is suctioned into the compression space; a roller rotatably provided in the compression space of the cylinder, and having a plurality of vane slots that provides a back pressure at one side thereinside and that is provided at a predetermined interval along an outer peripheral surface of the roller; and a plurality of vanes slidably inserted into the plurality of vane slots, respectively, and configured to rotate together with the roller, front end surfaces of which come into contact with the inner peripheral surface of the cylinder due to the back pressure to partition the compression space into a plurality of compression chambers. High-pressure refrigerant may be accommodated between one of the plurality of vanes and the inner peripheral surface of the cylinder.

A scroll pump includes first and second scroll members connected together by a plurality of idler assemblies configured to allow the second scroll member to move in an orbital path with respect to the first scroll member. A rotary bearing is connected to an end plate of the orbiting scroll member. A motor and motor coupler are coupled to the rotary bearing to move the bearing in an orbital path corresponding to the orbital path followed by the second scroll member. The rotary bearing may roll freely within the coupler.

A cooling system for a motor to power a compressor in a vapor compression system is provided. The cooling system includes a housing with a cavity enclosing the motor and defining a central axis and fluid directing features extending into the cavity and oriented parallel to the central axis. The cooling system further includes a fluid circuit configured to circulate a cooling fluid between the housing and the motor. The fluid circuit includes a first cooling fluid path defined by directing features that cause a first portion of cooling fluid to travel around a first portion of the motor and a second cooling fluid path defined by fluid directing features that cause a second portion of cooling fluid to travel around a second portion of the motor. The second portion of the motor is located opposite the first portion.

In a scroll compressor, at an end plate surface of a fixed scroll, an annular back pressure groove connected to a back pressure chamber is provided, and an arc-shaped first groove and an arc-shaped second groove are provided inside the back pressure groove in a radial direction. A distance between the second groove and the back pressure groove is shorter than a distance between the first groove and the back pressure groove. A revolving scroll is provided with a first hole and a second hole for guiding lubricant oil from an oil supply path to the end plate surface side of the fixed scroll. At least part of a movement locus of an opening of the first hole is included in the first groove. At least part of a movement locus of an opening of the second hole is included in the second groove. The first groove and the second groove at least partially overlap with each other in the radial direction.

A scroll compressor is disclosed, which may provide an oil supply path opened only in case of driving of a low pressure ratio to improve a differential pressure oil supply structure which may have a defect in oil supply in case of driving of the low pressure ratio.

An electric compressor includes a housing, a drive shaft, a motor, a movable scroll, and a fixed block. The fixed block is fixed to the housing and disposed between the motor and the movable scroll. The motor includes a stator and a rotor. The rotor has an introduction passage that is formed through the rotor in an axial direction of the drive shaft. The drive shaft includes a balance weight that is disposed between the fixed block and the motor and extends to a position where the balance weight covers at least a part of the introduction passage in a radial direction of the drive shaft in a view in the axial direction. The introduction passage includes a first passage located outward of the balance weight in a circumferential direction of the rotor and the drive shaft, and a second passage facing the balance weight in the axial direction.