An adjustable vane pump, in particular an oil pressure pump, with a suction side and a pressure side, with a housing and a rotor supported in the housing so as to be rotatable about a rotor axis. At least one vane is supported for movement in a radial direction. The housing comprises a housing floor and a housing cover transversely to the rotor axis, and an adjustment cage is arranged between the housing floor and the housing cover.

The present invention provides a variable displacement pump capable of improving controllability. A variable displacement pump includes a pump forming member, a movable member, a biasing member, a first control chamber, a second control chamber, and a control mechanism. The first control chamber is provided between an inner periphery of a containing chamber of a housing and an outer periphery of the movable member. Hydraulic oil is introduced from a discharge port into the first control chamber. The first control chamber has a volume that increases when the movable member moves in a direction counteracting a biasing force of the biasing member. The second control chamber is provided between the inner periphery of the containing chamber and the outer periphery of the movable member. The hydraulic oil is able to be introduced from the discharge port into the second control chamber via a supply/discharge passage or is able to be discharged from inside the second control chamber. The second control chamber has a volume that increases when the movable member moves in the same direction as the biasing force of the biasing member. The second control chamber is located adjacent to any of pump chambers in a discharge region or the discharge port via the movable member. The control mechanism can switch a state in which the second control chamber is opened to the supply/discharge passage and a state in which the second control chamber is closed to the supply/discharge passage.

A method of manufacturing a slide of a variable oil pump for a vehicle includes preparing a molded body for a slide of a variable oil pump using prealloy powder including, in percent (%) by weight of the entire composition, 0.45 to 0.55% of carbon (C), 2.8 to 3.2% of chromium (Cr), 0.45 to 0.55% of molybdenum (Mo), 0.35 to 0.5% of manganese (Mn), 0.1 to 0.25% of sulfur (S), and the remainder of iron (Fe) and inevitable impurities. A sintered body is prepared by sintering the molded body. The sintered body is slowly cooled such that a temperature of the sintered body reaches a first temperature range and rapidly cooled when the first temperature range is reached.

To provide a rotor portion 2A; a cam ring 21 having a rotor chamber 21a; a pump housing 1 provided with a pump chamber 11 having a control chamber 12 where the cam ring 21 is movably arranged to move the cam ring 21 using an oil pressure; a spool valve A for controlling the cam ring 21; a solenoid valve 81; and a relief valve 83. Each valve housing is provided with a communication hole 7 for supplying oil from the control chamber 12 of the pump chamber 11 to a portion between the control chamber 12 and at least one of the valve housings. A through-hole for discharging the oil is formed in the valve housing.

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.

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 pump including a port connecting a suction of the pump to a reservoir of a fluid; region an adjusting device for adjusting the delivery volume of the pump; a control valve, including a relief port, a control piston, and a tensing device which acts on the control piston; and an additional control device for generating a control force which acts on the control piston, counter to the tensing device, wherein the relief port is connected to the suction region by bypassing the reservoir.

A hydraulic device can include two or more rings, a rotor having a plurality of vanes, and an adjuster. The two or more rings can be rotatably mounted within the hydraulic device and arranged adjacent one another configured for relative rotation with respect to one another. The rotor can be disposed for rotation about an axis within the two or more rings and can have a plurality of circumferentially spaced slots, each slot having at least one of the plurality of vanes located therein. The plurality of vanes can be configured to be movable between a retracted position and an extended position where the plurality of vanes work a hydraulic fluid introduced adjacent to the rotor. The adjuster can be configured to translate linearly to rotatably position the two or more rings relative to one another to increase or decrease a displacement of the hydraulic fluid between the rotor and the two or more rings.

A pump which exhibits an adjustable delivery volume, the pump including (a) a pump housing comprising a delivery chamber; (b) a delivery rotor which can be rotated about a rotary axis within the delivery chamber, for delivering the fluid; (c) an adjusting device, including: (c1) an adjusting member which can be adjusted in the pump housing in order to adjust the delivery volume of the pump; (c2) a first setting chamber for generating a first setting pressure for adjusting the adjusting member; (c3) and a second setting chamber for generating a second setting pressure for adjusting the adjusting member; (d) a fluidically operable valve for adjusting the setting pressure of the first setting chamber; (e) and an electromagnetic valve, comprising: a pressure port for a setting fluid which is diverted from the high-pressure side; and a relief port for the setting fluid.

This oil pump includes a first volume-changing part provided between an inner rotor and an outer rotor and a second volume-changing part provided in the outer rotor. A plurality of outer rotor pieces, which is annularly connected to each other, of the outer rotor is circumferentially arranged in a state where a first engaging part and a second engaging part of the outer rotor pieces being adjacent to each other engage with each other such that a distance therebetween in a circumferential direction is variable.