A coupling assembly arranged between an input shaft and a rotor shaft of a supercharger includes a first hub, a second hub, a first side coupling assembly, a second side coupling assembly, a central hub and a plurality of coupler pins. The first hub is mounted for concurrent rotation with the input shaft. The second hub is mounted for concurrent rotation with the rotor shaft. The first side coupling assembly has a first side coupling body and a first side elastomeric insert. The first side coupling body includes an inboard body portion having a first series of pockets and an outboard body portion having a second series of pockets. The first side elastomeric insert has a first and second plurality of lobes. The pockets of the first and second series of pockets are tangentially offset relative to each other and each receive respective first and second plurality of lobes therein.

Disclosed herein may be an electric compressor. The electric compressor may include: a rear housing having a discharge chamber into which refrigerant is discharged; and an oil separator disposed in the discharge chamber and having a refrigerant inlet hole through which the refrigerant is drawn into the oil separator. The discharge chamber may protrude in a multi-stepped manner outwards from the rear housing such that a volume of the rear housing is increased, and based on the oil separator, an internal space of the discharge chamber may be divided into spaces having different volumes.

A rotary pump, preferably a vane cell pump or a pendulum slider pump, includes a stator and a rotor which rotates about a rotational axis within the stator. The rotor includes multiple delivery elements which move radially in relation to the rotational axis, and two adjacent delivery elements limit a delivery cell together with the outer surface area of the rotor and the inner surface area of the stator. At least two delivery cells, preferably two adjacent delivery cells, exhibiting a first maximum cell volume form a first delivery cell group and at least two other delivery cells, preferably two other adjacent delivery cells, exhibiting a second maximum cell volume form a second delivery cell group. The first maximum cell volume of the delivery cells of the first delivery cell group is larger than the second maximum cell volume of the delivery cells of the second delivery cell group.

A motor vehicle vacuum pump includes a pumping chamber in which a pump rotor rotates to compress a gas, an outlet chamber into which the gas exits, a separation wall which includes a valve opening and a valve seat arranged on an outlet side of the separation wall around the valve opening. The separation wall separates the pumping chamber from the outlet chamber. An outlet valve is formed as a non-return valve in the separation wall. The outlet valve is formed by the valve opening in the separation wall and includes a valve body with a closing body. The outlet valve has the gas exit therethrough from the pumping chamber into the outlet chamber. A corresponding part of the closing body is supported on the valve seat when the closing body is in a closed position. The valve seat and/or the corresponding part of the closing body includes microgrooves.

A gear configured to rotate as a unit with a shaft, the gear includes: a plurality of annular grooves formed on both side surfaces of the gear in a direction of a rotation axis of the shaft, at least partially overlapped when viewed from the direction of the rotation axis, and at least partially overlapped in a radial direction with respect to the rotation axis.

A rotary compressor includes a compression mechanism having a cylinder, a piston, and a Helmholtz muffler. The Helmholtz muffler has a resonance chamber in the compression mechanism and a communication groove formed on an end face of the cylinder to connect the cylinder and resonance chambers. The communication groove is open at the end face of the cylinder and has a pair of side wall portions and a bottom wall portion between the side wall portions. Each side wall portion has a first portion adjacent an open end of the communication groove and a second portion adjacent the bottom wall portion. A surface of the first portion is a flat or bowed surface. A surface of the second portion is a bowed surface having a predetermined curvature so as to be connected to the surface of the first portion and a surface of the bottom wall portion.

A compressor may include a shell. A compression mechanism may be disposed within the shell. A drive shaft may be disposed within the shell and drivingly engaged with the compression mechanism. A motor assembly may be drivingly engaged with the drive shaft and may include a rotor and a stator. A plurality of magnets may be disposed within the rotor and may cooperate with the stator to create an electromagnetic field between the rotor and the stator. A counterweight assembly may be secured to the drive shaft and configured to dynamically balance the compression mechanism and secure the plurality of magnets within the rotor.

Provided is a gear pump and a gear motor in which noise is reduced. A gear pump includes: gears which mesh and pair with each other; a casing including a gear housing chamber for housing the gears; and at least one hollow layer which is configured in the casing and divides the casing into at least inner walls and outer walls. Coincidence critical frequency of the inner walls and coincidence critical frequency of the outer walls are different. The hollow layer is formed between the gear housing chamber in the casing and an outer surface of the casing.

A compressor may include: a casing (10) having a refrigerant inlet space (V1) therein communicating with a suction pipe suctioning a refrigerant; a high/low pressure separation plate (90) provided by crossing an upper part of a compression unit (50) to partition the refrigerant inlet space (V1) positioned at a lower portion of the high/low pressure separation plate (90) and a refrigerant discharge space (V2) positioned at an upper portion thereof; and a discharge guide (100). In this case, the discharge guide (100) is provided in the refrigerant discharge space (V2) and is combined with an upper surface of the high/low pressure separation plate (90) to cover a communicating hole 92 of the high/low pressure separation plate communicating the refrigerant inlet space (V1) with the refrigerant discharge space (V2) and at least a portion thereof extends to a discharge pipe (14).

A scroll compressor includes a housing, a first scroll, a second scroll being configured to rotate relative to the first scroll about a driving axis of the scroll compressor. The second scroll has an end plate, a spiral element, and an adjustment portion adjusting a center-of-gravity of the second scroll. The adjustment portion has a bottom surface, a peripheral surface enclosing the bottom surface, and a connection surface connecting the bottom surface to the peripheral surface. The peripheral surface has a first peripheral surface and a second peripheral surface. A length of the first peripheral surface in a direction in which the driving axis extends is shorter than a length of the second peripheral surface in the direction in which the driving axis extends.