A gerotor pump has a pump housing defining a chamber and having a fluid inlet and a fluid outlet. An outer gear member is supported for rotation within the chamber about a first axis, the outer gear member having a series of internal teeth. An inner gear member or inner rotor is rotatably supported within the outer gear member about a second axis spaced apart from the first axis. The inner gear member defining a series of external teeth interposed with a series of external pockets. The inner gear member defines a fluid passage therethrough to fluidly connect two nonadjacent pockets, with another pocket independent of fluid passages. The fluid passage is configured to disrupt harmonics during operation to reduce pressure ripples and associated tonal noise.

A vane fluid pump for a vehicle component has a cam defining a continuous inner wall surrounding a cavity, and an inner rotor supported within the cam. The inner rotor has a cylindrical outer wall defining a series of slots equally spaced about the outer wall. A series of vanes is provided with each vane positioned within a respective slot of the inner rotor and extending outwardly to contact the continuous inner wall of the cam. Each vane provides a fluid barrier between adjacent pumping chambers formed between the cam and the inner rotor. A first vane of the series of vanes defines a passageway thereacross to fluidly connect adjacent pumping chambers. The passageway is configured to disrupt harmonics during operation to reduce pressure ripples and associated tonal noise. At least another vane is configured without any fluid passageways.

A pump device includes a shaft, a first gear pair, a second gear pair, a support pin, and a casing. The first gear pair includes a first driving gear which is disposed on the shaft and is rotatable together with the shaft, and a first driven gear driven by the first driving gear. The second gear pair includes a second driving gear which is disposed on the shaft coaxially with the first driving gear and is rotatable together with the shaft, and a second driven gear driven by the second driving gear and arranged coaxially with the first driven gear. The support pin penetrates the first driven gear and the second driven gear and rotatably supporting the first driven gear and the second driven gear. The casing covers the first gear pair and the second gear pair. The support pin is fitted to the casing to be fixed.

A vane fluid pump for a vehicle component is provided with an inner rotor supported within a cam. The inner rotor has an outer wall extending between first and second end faces, the outer wall defining a series of slots spaced apart about the outer wall to provide a series of outer wall sections. One of the wall sections defines a groove. Another of the wall sections is independent of grooves or is ungrooved. The pump has vanes positioned within respective slots of the inner rotor and extending outwardly to contact the continuous inner wall of the cam. The groove on the inner rotor is configured fluidly couple with a notch on the housing to provide fluid flow to the discharge port from an upstream pumping chamber to disrupt harmonics during operation to reduce pressure ripples and associated tonal noise.

A compressor is configured such that an axis center of a rotating shaft for transmitting rotation of a rotor to a compressing unit for compressing a refrigerant is offset from a rotor center of the rotor, and, when the rotor is divided into, with respect to the rotor center, a first portion located on a side in a direction from the axis center to the rotor center and a second portion located on a side in a direction from the rotor center to the axis center, a magnetic force of the first portion is stronger than a magnetic force of the second portion. This configuration allows the rotor to generate non-uniform magnetic attractive forces during the rotation of the rotor and thereby can suppress vibration generated due to rotation of an eccentric portion of the compressing unit and reduce noise.

A rotary compressor is disclosed. The rotary compressor may include a casing, a cylinder, main and sub bearings, a rotational shaft, a roller, at least one vane, and a vane support portion that axially supports the at least one vane formed on a bearing surface to extend along a reciprocating direction of the at least one vane from an inner circumferential surface of at least one back pressure pocket at an end of circumferential ends of the at least one back pressure pocket, adjacent to a contact point, and/or protrude axially from the inner circumferential surface of the at least one back pressure pocket and extend in a circumferential direction. This may secure a wide axial support area for a rear end of the at least one vane passing the contact point and/or near the contact point, to suppress or prevent axial tilting of the at least one vane, thereby reducing friction loss, wear, and vibration noise due to the axial tilting of the at least one vane during operation of the compressor.

A conduction noise filtering circuit configured to inhibit conduction noise is provided. The conduction noise filtering circuit includes a first coil part configured to be supplied with alternating current (AC) power, a second coil part configured to be connected to the first coil part in series, a detector configured to detect common mode noise from at least one selected from the first coil part and the second coil part, and a capacitor configured to supply a current offsetting common mode noise between power lines connecting the first coil part and the second coil part in series, based on an output signal of the

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.

The disclosure relates to a screw pump (2) comprising: a casing (3) with an inlet (30), an outlet (31) and a flow chamber (32) between the inlet and the outlet; and at least two screws (4, 5, 6) housed in the flow chamber to 5 force a fluid flow through the flow chamber from the inlet to the outlet; wherein the casing (3) comprises a shell (33) within which an insert (34) defining the flow chamber is housed.

Bi-helical toothed wheel (1) with non-encapsulating profile (4) for hydraulic gear apparatuses (2), configured to be bound to a support shaft (5) to form a driving or driven wheel of said hydraulic apparatus and comprising a plurality of teeth (6) extending with variable helix angle with a composite function in the longitudinal or axial direction of the tooth (6), wherein the teeth profile (4) keeps a shape continuity in each cross section thereof, wherein each tooth (6) in the longitudinal direction is divided into five zones: initial (A), proximal intermediate (B), central (C), distal intermediate (D) and terminal (E), where said initial (A), central (C) and terminal (E) zones have a variable helix angle () and said proximal intermediate (B) and distal intermediate (D) zones have a constant helix angle ().