The compressor includes a rotor that applies rotational power to a compressor unit, wherein the rotor includes a rotor core and an upper rotor-end plate, the rotor core has a plurality of through-holes through which a refrigerant passes, the upper rotor-end plate covers the upper rotor-end face of the rotor core, where one end of each of the plurality of through-holes is formed, the upper rotor-end plate has a plurality of upper openings that allow communication of the plurality of through-holes with an internal space in a compressor container, the plurality of upper openings are adjacent to the plurality of through-holes in the upper rotor-end face, and a plurality of upper inner peripheral-side adjacent areas, which are on the inner peripheral-side closer to a rotation axis than the plurality of through-holes, are exposed to the internal space.

A fluid pump includes a pump element where rotation of the pump element generates suction at the inlet and pressure at the outlet to move fluid through a fluid path. An inlet orifice directs a portion of the fluid through the accessory fluid path that includes a low-restriction return path providing a continuous flow of the fluid through the accessory fluid path and to an outlet orifice. A circuit board housing includes a contoured portion and a PCB with a thermistor in communication with contoured portion. The continuous flow is directed between the contoured portion and the outlet orifice between a rotor and the outer wall. The low-restriction return path maintains a temperature of the continuous flow of the fluid within the contoured portion of the accessory fluid path to be similar to a temperature of the fluid in the fluid path.

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 compressor includes a shell that defines an enclosed space inside the shell, an electric motor unit located in the enclosed space of the shell and configured to generate a driving force, and a compression unit located in the enclosed space of the shell and configured to compress refrigerant. The compression unit includes a cylinder and a piston that is configured to reciprocate in the cylinder based on the driving force transmitted from the electric motor unit. The shell includes a plurality of heat radiation fins that are located at an outer circumferential surface of the shell and that are configured to emit heat generated inside the shell to an outside of the shell.

A pump device includes a shaft , a motor unit that rotates the shaft, and a pump driven by the motor via the shaft and discharges oil. The pump device includes a first flow path for the oil that connects the inside of the pump and the inside of a housing, a second flow path for the oil provided between a stator and a rotor, and a third flow path for the oil that is connected to a suction port of a pump through the outside of the stator and the rotor in a radial direction from the second flow path. One or a plurality of grooves are provided on the outer peripheral surface of the rotor or the inner peripheral surface of the stator, and the groove is inclined with respect to an oil flow direction.

A shield for controlling the cooling within a hermetically cooled motor, and a compressor incorporating the shield are provided. The shield includes an insulator, at least one fastener, and a venting aperture. The insulator restricts the flow of a working fluid between a first side and a second side. The at least one fastener secures the insulator. The venting aperture controls a pressure differential between the first side and the second side. The venting aperture may include at least one hole through the insulator. The venting aperture may be provided as a hole through the insulator for the rotating shaft of the compressor.

A flange is held by a peripheral wall of an intermediate housing member and a peripheral wall of a motor housing member. In this state, bolts are passed through the intermediate housing member and the flange and are threaded to a peripheral wall of the motor housing member, thereby integrally fixing a shaft support housing member to the intermediate housing member and the motor housing member. Thus, the shaft support housing member sufficiently receives the fastening force of the bolts. Vibration of the shaft support housing member is therefore easily suppressed. The intermediate housing member includes a peripheral wall. Thus, the intermediate housing member has a higher stiffness than in a case in which the intermediate housing member does not have the peripheral wall.

An electric compressor includes a housing including a motor housing, a compressor housing, and a shaft support member, which are fastened with a fastening member, and a fluid passage. The shaft support member has a fitted surface fitted onto an opening of the motor housing and a flange portion extending from the fitted surface and interposed between a first end face of the motor housing and a second end face of the compressor housing. The flange portion has a through hole through which the fastening member is inserted and a passage-forming hole through which a first recessed portion and a second recessed portion are in communication with each other. The through hole and the passage-forming hole are arranged in a circumferential direction of the flange portion. The fluid passage is formed at least by the first recessed portion, the second recessed portion, and the passage-forming hole.

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.

Screw compressor with a compression chamber that is formed by a compression housing, in which a pair of meshed helical compressor rotors in the form of a screw are rotatably mounted and with a drive motor that is provided with a motor chamber formed by a motor housing, in which a motor shaft is rotatably mounted. The motor shaft drives at least one of the aforementioned two compressor rotors, where the compression housing and the motor housing are connected directly together to form a compressor housing, where the rotor shafts of the compressor rotors, as well as the motor shaft, extend along axial directions that are oblique or transverse to the horizontal plane. The motor chamber and the compression chamber have the same or similar pressure.