A rotary pump includes: a pump housing having a low-pressure inlet and a high-pressure outlet; a delivery rotor rotatable about a rotational axis and including multiple deliverers distributed over the circumference of the rotor for delivering a fluid from the low-pressure inlet to the high-pressure outlet; and a setting element for adjusting the delivery volume of the pump. The inlet end of the setting element includes a first circumferential portion which extends circumferentially in the rotational direction of the rotor and the axial width of which is smaller than the axial width of the deliverers and a second circumferential portion which adjoins the first circumferential portion in the rotational direction and the axial width of which is greater than the axial width of the first circumferential portion.

Discharge port (26) as arc-recessed discharge portion is formed by cutting on bottom surface (13a) of pump accommodating portion (13) of variable displacement pump. On mounting surface (1b) of housing body (1), first low pressure chamber (281) is formed at position overlapping with discharge port (26) in radial direction of pump structure (14) formed by driving shaft (3), rotor (4) and vanes (5) Drain hole (28b) communicating with low pressure portion located outside housing body (1) is formed on bottom surface (28a) of first low pressure chamber (281) along direction of rotation axis (O1) of pump structure (14). Low pressure portion has pressure that is hydraulic pressure of oil discharged from discharge port (26) or less. Oil from discharge port (26), having higher pressure than first low pressure chamber (281), flows into first low pressure chamber (281) by pressure difference between discharge port (26) and first low pressure chamber (281).

A fluid pump includes a rotor which is centered about an axis, the rotor having a rotor central chamber and a plurality of vane slots. A stator has a recess therein within which the rotor is located, the recess having a recess peripheral surface which is eccentric to the axis. Each vane slot includes a vane therein such that the vanes define a plurality of pumping chambers which expand and contract based on rotational position the rotor relative to the stator. A positioning ring is located within the rotor central chamber such that the positioning ring engages each vane and such that the positioning ring urges each vane into contact with the recess peripheral surface. The positioning ring is radially aligned with a midpoint of each vane.

A variable displacement oil pump includes: a variable displacement mechanism that is able to change a discharge amount per rotation of an input shaft. The variable displacement mechanism includes a pump housing, an oil pressure chamber provided in the pump housing, and a capacity adjustment member displaced by oil pressure from the oil pressure chamber. The capacity adjustment member is configured to be operated when receiving control oil pressure that is supplied from a control valve to the oil pressure chamber. The pump housing has an oil release hole that is opened to face the oil pressure chamber and that penetrates a wall section of the pump housing to partially release oil.

The present disclosure relates to a control circuit for a variable displacement pump in a vehicle transmission, including: a regulator valve configured to regulate displacement control fluid to the variable displacement pump; and a response limiter in communication with the regulator valve, configured to mitigate pressure oscillations in the control circuit.

A variable displacement vane pump that includes a biasing assembly that applies a first biasing force to a pump control ring when the pump control ring is located a first position and a second position and applies a second biasing force when the pump control ring is located between the second position and a third position. The first position of the pump control ring corresponds to a maximum volumetric capacity of the pump, the second position corresponds to an intermediary volumetric capacity of the pump, and the third position corresponds to a minimum volumetric capacity of the pump. Fluid pressure within a control chamber urges the pump control ring toward the third position.

This disclosure generally relates to an automatic bicycle, particularly to a hydraulic automatic transmission bicycle which can automatically and adaptively change gear ratios. More particularly, this disclosure relates to those hydraulic automatic transmission bicycles which use fluid pressure to change such gear ratios, and which include various hydraulic automatic transmissions which may be provided in various configurations and may operate in various methods and sequences to provide automatic and infinitely variable gear ratios.

An automobile vehicle variable displacement pump includes a pump body having a pump shaft extending through the pump body. A rotor is connected to the pump shaft and co-rotates with the pump shaft. The rotor has multiple radially outwardly directed slots. A vane support ring supports multiple vanes, the vanes individually slidably received in one of the slots of the rotor. A slide is rotatably connected to the pump body having the rotor and the vane support ring positioned within an inner wall of the slide. A bow spring plate defining a biasing member directly contacts the slide to bias the slide to rotate about an arc of curvature.

An improved vane pump assembly is provided. The vane pump assembly includes a housing with an open chamber that is circular in shape when viewed in cross-section and has an inner wall that surrounds the open chamber. A rotor is rotatably disposed in the open chamber of the housing. As with the open chamber, the rotor is circular in shape when viewed in cross-section and has a diameter. The rotor further has at least one through-passage which extends diametrically across the rotor. The rotor is positioned such that it has a center that is offset from a center of the circular open chamber of the housing.

A variable displacement lubricant pump for providing a pressurized lubricant for a motor vehicle. The pump includes a pump rotor which rotates about a rotor axis and a control ring which is shiftable. The pump rotor includes a pump rotor shaft, a rotor body having vane slits, and pump vanes which are arranged in and which axially slide in the vane slits. The control ring can be actuated to set an eccentricity of the control ring to define a volumetric pump performance. The control ring defines a pump chamber which is separated by the pump vanes into pumping compartments. The control ring includes a control ring main body, bushing rings which are arranged separately at a radial inside of the control ring main body, and a radial inlet opening and/or a radial outlet opening. The radial inlet opening and/or the radial outlet opening is/are arranged axially between the bushing rings.