A variable displacement lubricant pump includes a housing, a control ring arranged in the housing, an inlet chamber and an outlet chamber, and a lateral slide bearing. The control ring is shiftable, radially confines a pumping chamber, and comprises a drainage channel. The outlet chamber and the inlet chamber are arranged at opposite lateral sides of the control ring. The lateral slide bearing is arranged at the lateral side of the control ring where the outlet chamber is arranged and comprises a first lateral slide bearing surface defined by the static housing, a second lateral slide bearing surface arranged opposite to the first lateral slide bearing surface which is defined by the control ring, and a lateral slide bearing gap defined between the first and second lateral slide bearing surfaces. The drainage channel of the control ring fluidically connects the lateral slide bearing gap with the inlet chamber.

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.

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 dual vane pump system includes first and second vane pumps having first and second rotors with a plurality of vanes moving radially inwardly and outwardly of the first and second rotors, and into contact with an inner surface of the first and second outer liners. A first pre-pressurization passage connects a first pump inlet in the first pump that is at discharge pressure to a second pump outlet in the second pump which is upstream of the second discharge opening. There is a coupling connecting the first and second rotors for rotation together. The pre-pressurization passage extending through the bearing.

A rotary pump, preferably a vane cell pump or a pendulum slider pump, includes a stator and a rotor which rotates about a rotational axis within the stator. The rotor includes multiple delivery elements which move radially in relation to the rotational axis, and two adjacent delivery elements limit a delivery cell together with the outer surface area of the rotor and the inner surface area of the stator. At least two delivery cells, preferably two adjacent delivery cells, exhibiting a first maximum cell volume form a first delivery cell group and at least two other delivery cells, preferably two other adjacent delivery cells, exhibiting a second maximum cell volume form a second delivery cell group. The first maximum cell volume of the delivery cells of the first delivery cell group is larger than the second maximum cell volume of the delivery cells of the second delivery cell group.

A fluid pumping system for a vehicle having an internal combustion engine comprises a housing, an electric motor, a rotatable first input adapted to be driven by the internal combustion engine, a rotatable second input driven by the electric motor, and a pump. The pump includes a drum selectively rotated about a drum axis of rotation by one of the first input and the second input, and a pump rotor selectively rotated by the other of the first input and the second input. The drum includes a cam ring having a cavity in receipt of the pump rotor. The drum includes a first fluid inlet port and a second fluid inlet port on opposite sides of the drum such that fluid entering the cavity through the first and second fluid ports flows axially in a direction parallel to the drum axis of rotation. The drum includes a radially extending outlet port such that pumped fluid flows radially out of the cavity. The housing contains the electric motor and the pump.

Variable displacement pump has first control hydraulic chamber 21 giving force to cam ring 5 in direction that decreases volume variation of each pump chamber 13 by internal pressure, second control hydraulic chamber 22 giving force to cam ring in direction that increases volume variation of each pump chamber by internal pressure, first seal surface 44 formed on both end surfaces of cam ring, which are in sliding-contact with both opposing inside surfaces of pump body 1 and cover member 2, and sealing gap between each pump chamber and first control hydraulic chamber, and second seal surface 45 sealing gap between each pump chamber and second control hydraulic chamber at outlet section side. Radial direction width W2 of second seal surface is greater than that W1 of first seal surface. Increase in weight of the pump can be suppressed while suppressing increase in pump control pressure against intention of control.

A vane for use in a rotary vane pump. The vane has a length L extending between a first edge of the vane and a second edge of the vane and a width W extending perpendicular to said length, the width extending between a third edge of said vane and a fourth edge of the vane, and further comprising a channel extending through said vane and provided at a position along said length L of said vane. The channel maybe positioned away from said first and second edges such that said vane has a constant length L along its width. The width of the channel may vary in shape between first and second points along the length of the vane. The channel may have a triangular shape, a rectangular shape or a circular shape. A method for detecting the decrease in length of the vane is also described.

A vane for use in a rotary pump “R” a first portion P1 having a first thickness T1 and a second portion P2 which has a second thickness T2 that is greater than the first thickness T1. In some examples, the vane has an L-shaped cross-section. In other examples, said second portion P2 has a circular cross-section.

A rotary vane pump includes a pump housing, a stator, a rotor, a plurality of vanes which are accommodated in the rotor so as to be displaceable in the radial direction, so that they delimit a plurality of pump chambers between themselves, the stator and the rotor. A radially inner cam surface is provided, against which the vanes rest, wherein secondary chambers are delimited in the radial direction between the cam surface and the rotor and in the circumferential direction between the vanes, with a suction inlet and a pressure outlet being assigned to the secondary chambers.