The invention relates to an oscillating piston pump for liquid and gaseous fluids, comprising: a pump housing having at least two sector-shaped working chambers, which are diametrically opposed relative to a pivot axis arranged in-between; an oscillating piston, having at least two displacement portions which extend diametrically relative to the pivot axis and are each received pivotably in one of the working chambers; an electric drive, which moves the oscillating piston alternately on a pivot movement between two turning points delimited within the working chambers; a group of outlet valves, which ensure the discharge of a volume displaced from the working chambers to a pump outlet; and a group of inlet valves, which ensure the entry of a volume flowing into the working chambers from a pump inlet. The group of outlet valves or inlet valves is arranged on both sides of each working chamber and communicates through the pump housing with the pump outlet or the pump inlet. The other group of inlet valves or outlet valves is arranged in the oscillating piston and communicates via a cavity in the oscillating piston with the pump inlet or the pump outlet.

A vacuum pump suitable for mounting to an engine includes: a casing having a cavity, the cavity including an inlet and an outlet; a moveable member arranged for rotation inside the cavity, the movable member being movable to draw fluid into the cavity through the inlet and out of the cavity through the outlet so as to induce a reduction in pressure at the inlet; a valve seat at the outlet; and an outlet valve including a reed element and a stop for restricting movement of the reed element. The stop is movable between a first operating position, in which movement of the reed element is restricted to a first opening degree, and a second start-up position, in which movement of the reed element is restricted to a second opening degree, which is larger than the first opening degree.

An air compressor contains: a torque gear on which a central orifice and a connection rod are arranged. The central orifice has screw threads defined thereon and corresponds to one of multiple positioning orifices of a base, the one positioning orifice is configured to accommodate a bearing, and a screw bolt is inserted through the bearing in the base so as to screw with the central orifice via the torque gear. The connection rod of the torque gear is rotatably connected with a piston so that the piston moves in a cylinder to produce compressed air, the torque gear matingly contacts with the bearing along the screw bolt, and the bearing is not broken in the one positioning orifice, thus moving the piston in the cylinder reciprocately.

A plunger and cylinder assembly for the fluid end of a reciprocating pump. The assembly comprises a traveling cylinder, a stationary plunger, and an optional sleeve secured to the traveling cylinder in a detachable manner. The traveling cylinder is displaced along its axis by a thrust component and acts cooperatively with the stationary plunger to create a pressure change in the reciprocating pump.

The invention relates to a compressor assembly for supplying pressure medium to a tire cavity of a vehicle wheel that can be mounted on a wheel hub which can be mounted on a wheel carrier so as to be rotatable about an axis of rotation. The compressor assembly includes a wheel mount-side transmission component or the hub-side transmission component, which includes a cylindrical cam.

The present disclosure provides a two-dimensional motor piston pump, including a two-dimensional motor and a two-dimensional piston pump. The two-dimensional motor and the two-dimensional piston pump are nested with each other and arranged coaxially. The two-dimensional motor includes a stator and an outer rotor, and the outer rotor is coaxial with the stator and is sleeved outside the stator. The two-dimensional piston pump includes: a flow distribution mechanism including a flow distribution rotor and a pump body, a piston mechanism including a left cam and a right cam; a roller assembly including a roller and a roller shaft, and a pump housing, a left end cover, and a right end cover.

The present disclosure provides a two-dimensional motor piston pump, including a two-dimensional motor and a two-dimensional piston pump. The two-dimensional motor and the two-dimensional piston pump are nested with each other and arranged coaxially. The two-dimensional motor includes a stator and an outer rotor, and the outer rotor is coaxial with the stator and is sleeved outside the stator. The two-dimensional piston pump includes: a flow distribution mechanism including a flow distribution rotor and a pump body, a piston mechanism including a left cam and a right cam; a roller assembly including a roller and a roller shaft, and a pump housing, a left end cover, and a right end cover.

An active gas regenerative refrigerator includes a plurality of compressor-expander units, each having a hermetic cylinder with a drive piston configured to be driven reciprocally therein, and a quantity of working fluid in each end of the cylinder. A piston seal in a central portion of the cylinder prevents passage of the working fluid between ends of the cylinder. Movement of the piston to a first extreme results in radial compression of one of the quantities of working fluid in a cylindrical gap formed between one end of the piston and an inner surface of the cylinder, while the other quantity is expanded in the opposite end of the cylinder. The piston includes a plurality of magnets arranged in pairs, with magnets of each pair positioned with like-poles facing each other. A piston drive is configured to couple with transverse magnetic flux regions formed by the magnets.

A pump mechanism for vacuum sealing an airtight cavity formed by a container and a lid, including a bore having a first one-way seal allowing air from the airtight cavity to enter the bore and blocking air inside the bore from returning to the airtight cavity and a second one-way seal allowing air inside the bore to leave the bore without returning to the airtight cavity and blocking air outside of the bore from entering the bore, a piston disposed inside the bore, and a chamber of air enclosed by the bore, the first and second one-way seals, and the piston, wherein actuation of the piston in a first direction causes air to evacuate the airtight cavity and enter the chamber through the first one-way seal, and wherein actuation of the piston in a second direction causes air to exit the chamber through the second one-way seal.

A bearing arrangement for a unit that is mutually turnable around a center of rotation (R) comprising an external part (1) and an internal part (7), which, with the aid of high hydraulically acting pressure, is arranged to achieve a reciprocating rotary motion, or that is arranged to achieve a high hydraulic pressure from an applied torque from a reciprocating motion, whereby the external part (1) is provided with side walls arranged to axially surround at least a part of the internal part (7), and whereby the external part (1) comprises a radially inwardly arranged and essentially surrounding cavity (11, 12, 13, 14) in which the internal part (7) is arranged such that it can be rotated, which cavity (11, 12, 13, 14) is limited in the circumferential direction by at least one wing (3, 4) that protrudes inwards from the external part (1) and also limited by at least one wing (9, 10) that protrudes radially outwards from the internal part (7), which wings (3, 4, 9, 10) limit at least two chambers or compartments (11, 12, 13, 14) between the external part (1) and the internal part (7). At least one of the side walls of the external part is fixed connected with the, at least one, wing (3, 4) that protrudes radially inwards towards the internal part (7), which wing demonstrates a surface that faces radially inwards and that has a circular concave curvature for connection with an outwardly facing circular convex contact surface (8) at the internal part (7).