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 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.

A variable hydraulic pump include a rotor mounted on a pump housing of which a housing spring end is formed, a pivot pin, an outer ring rotatably coupled to the pivot pin and of which a ring spring end is formed, a spring mounted between the housing spring end and the ring spring end, a pressure chamber formed in the pump housing to push the outer ring, a plurality of vane provided to form a plurality of pockets, an input port to supply oil to the plurality of pockets and a discharge port to exhaust oil supplied to the plurality of pockets, wherein at the reference position of the outer ring, the angle between a first imaginary line connecting the center of the rotor and the pivot pin and a second imaginary line connecting the ring spring end and the pivot pin is 0 to 10 degrees.

A variable displacement oil pump includes an adjustable member that is configured to shift according to changes in pressure inside a control oil chamber. The adjustable member has a long hole. A guide pin is disposed inside the long hole. The guide pin is fixed to either a housing or a cover of the variable displacement oil pump. The width of the long hole is larger at a part of the long hole farther away from a fixed end of the guide pin in its lengthwise direction than at a part thereof closer to the fixed end.

A variable displacement lubricant pump for providing a pressurized lubricant for an internal combustion engine includes a control ring configured to be shiftable, a pump rotor comprising a plurality of slidable vanes which are configured to rotate in the control ring, a hydraulic control chamber configured to directly actuate the control ring, a valve bore, and a temperature control valve configured to connect or disconnect the temperature control opening to an atmospheric pressure. The hydraulic control chamber comprises a side wall comprising a temperature control opening arranged therein. The temperature control valve comprises a switching strip which comprises a switching temperature. The switching strip is configured to be in an open position if a temperature is below the switching temperature, and to be in a closed position if the temperature is above the switching temperature so as to close the valve bore.

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.

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.

A pump is provided, which includes: an internal housing inside which a vane rotor is housed; a pump housing 1 in which the centre of rotation of the vane rotor is immovable and the internal housing is able to move; a first control oil chamber which causes the internal housing to move in a direction of decreasing the discharge volume; and a second control oil chamber which causes the internal housing to move in a direction of increasing the discharge volume; a pressure adjustment valve; a temperature-sensitive valve; and an elastic member which elastically impels the internal housing. A flow passage area of the temperature-sensitive valve changes gradually with change in oil temperature, and the pressure adjustment valve changes a discharge volume in accordance with increase in pressure of the discharge oil.

A variable displacement vane pump includes: a restrictor configured to impart resistance to flow of working fluid discharged from the pump chambers; a control valve configured to introduce the working fluid which is discharged from the pump chambers to the first fluid pressure chamber as a differential pressure between upstream and downstream of the restrictor is increased, the control valve being configured to discharge the working fluid in the first fluid pressure chamber as the differential pressure between upstream and downstream of the restrictor is reduced; a suction passage configured to guide the working fluid to be sucked into the pump chambers, the suction passage being configured to always communicate with the second fluid pressure chamber; and a guiding passage configured to allow communication between the control valve and the second fluid pressure chamber, the guiding passage being configured to guide the working fluid, which is discharged from the first fluid pressure chamber to the control valve, to the second fluid pressure chamber.

A vane pump unit assembled into a housing includes a rotor; a plurality of vanes; a cam ring; a first plate; a second plate; a connecting bar that has a first end portion fixed to the first plate, and a second end portion which protrudes from the second plate; and a clip that prevents the second plate and the cam ring from slipping out of the connecting bar. Before the clip is assembled into the housing, the retaining of the clip is positioned at least either between the first plate and the cam ring or between the second plate and the cam ring, in a place where a gap is formed. After the clip is assembled into the housing, the housing interposes the first plate, the cam ring, and the second plate in the axial direction, and the first and second plates are in close contact with the cam ring.