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 vane rotary compressor may include a cylinder provided with at least one outlet port; a plurality of bearings coupled to both sides of the cylinder in an axial direction of the cylinder to form a compression space together with the cylinder; a rotational shaft radially supported by the plurality of bearings; a roller rotatably coupled to the rotational shaft and provided with a plurality of vane slots formed in a circumferential direction, each having a first end opened to an outer circumferential surface thereof; a plurality of vanes slidably inserted into the plurality of vane slots of the roller, respectively, and protruding toward an inner circumferential surface of the cylinder to partition the compression space into a plurality of compression chambers, respectively; a discharge valve coupled to the cylinder to open and close the at least one outlet port; and at least one bypass hole formed in at least one of the plurality of bearings or formed in the cylinder to bypass a portion of refrigerant compressed in the compression chamber.

A compressor includes a shell, first and second scroll members, a fitting assembly and a valve assembly. The first scroll member includes a first end plate having a first spiral wrap extending therefrom. The second scroll member includes a second end plate having a second spiral wrap extending therefrom and an injection passage formed in the second end plate. The second spiral wrap is meshingly engaged with the first spiral wrap to form compression pockets. The injection passage is in fluid communication with the compression pockets. The fitting assembly is in fluid communication with the injection passage. The valve assembly coupled to one of the second scroll member and the fitting assembly and movable between a closed position in which fluid communication between the compression pockets and the suction chamber is prevented and an open position in which fluid communication between the compression pockets and the suction chamber is allowed.

A compressor includes a shell, first and second scroll members, a fitting assembly and a valve assembly. The first scroll member includes a first end plate having a first spiral wrap extending therefrom. The second scroll member includes a second end plate having a second spiral wrap extending therefrom and an injection passage formed in the second end plate. The second spiral wrap is meshingly engaged with the first spiral wrap to form compression pockets. The injection passage is in fluid communication with the compression pockets. The fitting assembly is in fluid communication with the injection passage. The valve assembly coupled to one of the second scroll member and the fitting assembly and movable between a closed position in which fluid communication between the compression pockets and the suction chamber is prevented and an open position in which fluid communication between the compression pockets and the suction chamber is allowed.

An electric pump system and method of operating the same involves pumping a fluid through a fluid passageway defined in a mechanical pump from a pump inlet to a hollow shaft of a motor, through the hollow shaft to an internal motor cavity defined by a housing of the motor, and through another fluid passageway defined in the motor housing and mechanical pump that leads to a pump outlet. The system and method further involve pumping the fluid through another fluid passageway defined in the mechanical pump from yet another pump inlet to the pump outlet. The temperature of fluid exiting the hollow shaft can be assessed and used by an electronic control unit (ECU) of the electric pump system to control the same. The electric pump system can be part of a cooling and lubrication system for an electric vehicle transmission, gearbox, differential or transfer case, for example.

An electric pump system and method of operating the same involves pumping a fluid through a fluid passageway defined in a mechanical pump from a pump inlet to a hollow shaft of a motor, through the hollow shaft to an internal motor cavity defined by a housing of the motor, and through another fluid passageway defined in the motor housing and mechanical pump that leads to a pump outlet. The system and method further involve pumping the fluid through another fluid passageway defined in the mechanical pump from yet another pump inlet to the pump outlet. The temperature of fluid exiting the hollow shaft can be assessed and used by an electronic control unit (ECU) of the electric pump system to control the same. The electric pump system can be part of a cooling and lubrication system for an electric vehicle transmission, gearbox, differential or transfer case, for example.

A priming pump may include a housing; an inlet passageway inside of the housing; an outlet passageway inside of the housing; a divider, inside of the housing, separating the inlet passageway and the outlet passageway; a connecting passageway through the divider in fluid communication with the inlet passageway and the outlet passageway; a valve, disposed in the connecting passageway, configured for one-way fluid flow from the inlet passageway to the outlet passageway; a rotary pump, inside of the housing, having an inlet in fluid communication with the inlet passageway and an outlet in fluid communication with the outlet passageway; and a shaft connected to the rotary pump and extending through the housing, the shaft configured for rotation by an external driving mechanism.

A priming pump may include a housing; an inlet passageway inside of the housing; an outlet passageway inside of the housing; a divider, inside of the housing, separating the inlet passageway and the outlet passageway; a connecting passageway through the divider in fluid communication with the inlet passageway and the outlet passageway; a valve, disposed in the connecting passageway, configured for one-way fluid flow from the inlet passageway to the outlet passageway; a rotary pump, inside of the housing, having an inlet in fluid communication with the inlet passageway and an outlet in fluid communication with the outlet passageway; and a shaft connected to the rotary pump and extending through the housing, the shaft configured for rotation by an external driving mechanism.

An oil pump includes: an outer rotor including internal teeth; an inner rotor including external teeth meshing with the internal teeth; a drive shaft connected to the inner rotor and configured to rotationally drive the inner rotor; and a housing including a pump chamber accommodating the inner and outer rotors. In the housing, a suction port and a discharge port are formed. The discharge port includes a first discharge port and a second discharge port. The suction port includes first and second suction ports respectively disposed on the same side as the first and second discharge ports. A pressure reducing oil passage communicating with the second discharge port and configured to reduce pressure of oil in the second discharge port is formed on the side of the second discharge port.

A pump apparatus includes a housing, a shaft, a rotor, a plurality of vanes, a pressure relief passage, and a bearing. The housing includes suction ports and discharge ports. The rotor and the vanes transport hydraulic oil to the discharge ports. The hydraulic oil is sucked from the suction ports. The pressure relief passage is defined in a portion of the housing facing an outer peripheral surface of the shaft. The pressure relief passage brings the discharge ports into communication with a low pressure region where the hydraulic oil is low in pressure. When a pressure of the hydraulic oil in the discharge ports is lower than a first predetermined pressure, the bearing keeps the pressure relief passage out of communication with a passage. When the pressure of the hydraulic oil in the discharge ports has increased to reach or exceed the first predetermined pressure, the bearing brings the pressure relief passage into communication with the passage.