Provided is a fluid-pump inner rotor that can be easily fitted to an outer rotor. This fluid-pump inner rotor includes a rotor member having a through hole along a rotational axis and a shaft member fitted in the through hole. Fitting strength between a first hole region provided in an inner face of the through hole of the rotor member which region extends along a rotational axis of the rotor member from one of end faces thereof perpendicular to this rotational axis and a first shaft region provided in an outer face of the shaft member is set greater than fitting strength between a second hole region provided in the inner face of the through hole of the rotor member and a second shaft region provided in the outer face of the shaft member.

A multiple vane kinetic system produces variation in an enclosed volume between pairs of radial vane sets independent of each other and coaxial with a central axis within a annular casing that encapsulates the vane sets. The system operates in a sequence where the vane sets function as rotating links of the mechanism for a particular period, which is preceded and succeeded by another period where either vane sets successively alternate between being a fixed link and a rotating link of the mechanism and during the former period the volumes between vanes remain constant as long as the vane sets have equal angular velocities, otherwise varies at rates proportional to differing angular velocities. The two time periods are controlled by timing devices actuating vane sets to be coupled and decoupled with a power shaft and the variation in length of two time periods makes roto-dynamic variable displacement machine.

An oil pump is provided. The oil pump comprises a shell, a rotor mounting part on the shell, and a rotor mechanism disposed on the rotor mounting part. The shell has an inlet and an outlet and defines a low-pressure oil chamber and a high-pressure oil chamber therein. A buffer chamber is defined between the low-pressure oil chamber and the high-pressure oil chamber, and a barrier wall is disposed between the buffer chamber and the low-pressure oil chamber. An engine cover comprising the oil pump and an engine comprising the engine cover are also provided.

A rotary compressor (100) includes a closed casing (1), a cylinder (15), a piston (28), a lower bearing member (7), a vane (33), a suction port, a discharge port (41), and a partition member (10). The partition member (10) is attached to a second principal surface (7a) of the lower bearing member (7) located on the opposite side to the cylinder (15) so as to form a refrigerant discharge space (52) serving as a flow path of a refrigerant discharged from a discharge chamber through the discharge port (41). The refrigerant discharge space (52) is limited so that a region where the refrigerant discharge space (52) is not present is formed on the same side as the suction port with respect to a first reference plane, and in that region, the second principal surface (7a) of the lower bearing member (7) is in contact with an oil in an oil reservoir (22) directly or via the partition member (10).

There is provided an oil-free air compressor that prevents oil from entering a compressor body by preventing a reverse rotation of the compressor body when the compressor is in shutdown, while improving the rust prevention effect, and that has improved reliability. An oil-free air compressor 100 includes an oil-free compressor body 1 that compresses air, and that outputs the compressed air; a cooler 5 that is connected to the compressor body, and that cools the compressed high-temperature air; a dry air supply mechanism for supplying dry air to an output side of the compressor body; and a mechanism for preventing a reverse rotation of the compressor body during a shutdown of the compressor.

A compressor includes a shell and a main bearing housing positioned within the shell. The main bearing housing includes a scroll assembly positioned within the shell and positioned relative to a first cavity of the main bearing housing, the scroll assembly includes a non-orbiting scroll, an orbiting scroll, and a cylindrical hub, and a coupling positioned between the orbiting scroll and a fixed component and movable relative to at least one of the orbiting scroll and the fixed component. A first seal may be positioned between the orbiting scroll and the coupling, a second seal may be positioned between the coupling and the main bearing housing, and a third seal may be positioned between the cylindrical hub and the main bearing housing, wherein the main bearing housing and the orbiting scroll define a pressure cavity.

A refrigerant compressor which has a drive unit and a compressor unit coupled thereto, wherein the drive unit has a motor housing through which refrigerant can flow and accommodates an electric motor with a rotatable shaft, wherein the compressor unit accommodates a scroll compressor which is driven by the shaft, wherein the motor housing includes a housing wall exposed to sucked-in refrigerant and an inverter unit joined thereto and accommodates an inverter circuit board, forming a fluid-tight inverter housing, wherein the inverter circuit board has a component arrangement formed with heat-producing electronic components, in particular with at least one DC link capacitor and multiple electronic power switches, and has at least two different component heights perpendicular to the inverter circuit board and is accommodated in multiple mouldings, which are formed according to the component heights, on the refrigerant-exposed housing wall and is thermally coupled to said mouldings.

The present invention provides a scroll compressor comprising: a casing forming the outer appearance and having an oil storage space; an electromotive part installed inside the casing to generate power; a rotation shaft rotatably installed in the electromotive part; a compression part having an orbiting scroll installed to be capable of orbital rotation around the rotation shaft and a fixation scroll coupled to and engaged with the orbiting scroll to form a compression chamber between the orbiting scroll and the fixation scroll; and a bushing disposed between the fixation scroll and the rotation shaft and coupled to the outer circumference of the rotation shaft so as to rotate with the rotation shaft, wherein the bushing is supported by one surface provided inside the fixation scroll.

An exhaust gas recirculation pump for an internal combustion engine that includes an electric motor assembly having an electric motor disposed within an electric motor housing. A roots device is coupled to the electric motor. The roots device includes a housing defining an internal volume. Rotors are disposed in the internal volume and connected to the electric motor. A bearing plate is attached to the housing wherein the bearing plate and an outer cover attached to the bearing plate defines an oil cavity. A transmission assembly is positioned on an opposing side of the housing relative to the electric motor and in the oil cavity.

A vortex compressor includes (i) a housing, (ii) an interior chamber housed in the housing, (iii) a compression assembly having a static scroll fixed to the housing and a dynamic scroll mated and movably disposed with the static scroll, wherein a compression cavity is disposed between the static scroll and the dynamic scroll, (iv) a drive assembly having a main shaft and a drive plate connecting to the dynamic scroll, and the main shaft drives the dynamic scroll to revolve through the drive plate, and (v) and an anti-turn assembly for preventing the drive plate from self-rotation.