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.

The present invention relates to a gear pump having a housing that has an inflow for the liquid to be conveyed, that has an outflow for the conveyed liquid, and that has a pump chamber in which the gear or gears for conveying the liquid are present, with at least one bearing position being present in the housing, in which bearing position at least one gear is rotatably received, wherein the inflow is in a different plane than the outflow; and wherein at least one first flushing passage that extends up to the bearing position(s) is in direct or indirect fluid communication with the inflow and/or with the outflow.

An internal gear pump (100) comprises: a rotor/torque ring comprising an internally lobed (140) rotor (130) and a torque ring (120) extending beyond at least a first end (134) of the rotor; an externally lobed (160) idler (150) encircled by the rotor; a hollow shaft (190) supporting the idler; a pressure relief element (200) positioned to shift between a first condition and a second condition; and a spring (210) biasing the pressure relief element toward the first condition from the second condition. The torque ring has at least one pressure relief port (240A, 240B) positioned so that: in the first condition, the pressure relief element blocks a path from an interior volume (235) of the pump to the pressure relief port; and in the second condition, relative to the first condition the pressure relief element does not block the path.

An internal gear pump (100) comprises: a rotor/torque ring comprising an internally lobed (140) rotor (130) and a torque ring (120) extending beyond at least a first end (134) of the rotor; an externally lobed (160) idler (150) encircled by the rotor; a hollow shaft (190) supporting the idler; a pressure relief element (200) positioned to shift between a first condition and a second condition; and a spring (210) biasing the pressure relief element toward the first condition from the second condition. The torque ring has at least one pressure relief port (240A, 240B) positioned so that: in the first condition, the pressure relief element blocks a path from an interior volume (235) of the pump to the pressure relief port; and in the second condition, relative to the first condition the pressure relief element does not block the path.

A pump device includes a flow control valve that returns a part of working fluid discharged from a pump to the suction side, and the flow control valve includes a valve body, a first fluid pressure chamber that is provided so as to face against a first-side end surface of the valve body and that is communicated with a discharge channel, a second fluid pressure chamber that is provided so as to face against a second-side end surface of the valve body and that is communicated with the discharge channel, a biasing member that is accommodated in the second fluid pressure chamber for biasing the valve body in the valve-closing direction, and a pressure regulator that is provided in a communicating passage through which the discharge channel is communicated with the second fluid pressure chamber and that adjusts pressure in the second fluid pressure chamber.

A pump device includes a flow control valve that returns a part of working fluid discharged from a pump to the suction side, and the flow control valve includes a valve body, a first fluid pressure chamber that is provided so as to face against a first-side end surface of the valve body and that is communicated with a discharge channel, a second fluid pressure chamber that is provided so as to face against a second-side end surface of the valve body and that is communicated with the discharge channel, a biasing member that is accommodated in the second fluid pressure chamber for biasing the valve body in the valve-closing direction, and a pressure regulator that is provided in a communicating passage through which the discharge channel is communicated with the second fluid pressure chamber and that adjusts pressure in the second fluid pressure 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.

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 hydraulic pump is described, comprising at least one inlet duct for a fluid, at least one outlet duct for the fluid and at least one pumping unit interposed between the inlet and outlet ducts. At least one multifunction valve is interposed between the inlet duct, upstream of the pumping unit, and the outlet duct, downstream of the pumping unit, which valve is configured to divert the flow of fluid from the inlet duct to the outlet duct without the fluid flowing into the pumping unit. The multifunction valve comprises a valve body that defines an inner bypass channel in which a shutter element is axially movable, an actuator member operatively associated with the shutter element and configured to move it from a closing position to an opening position of the bypass channel, and an elastic contrast element operatively associated with the shutter element and configured to keep it in the first closing position of the bypass channel when such shutter element is not actuated by the actuator member. The actuator member consists of a bias spring manufactured with a shape memory alloy, configured to move the shutter element from the first closing position to the second opening position of the bypass channel when a predefined temperature value is reached.

A hydraulic pump is described, comprising at least one inlet duct for a fluid, at least one outlet duct for the fluid and at least one pumping unit interposed between the inlet and outlet ducts. At least one multifunction valve is interposed between the inlet duct, upstream of the pumping unit, and the outlet duct, downstream of the pumping unit, which valve is configured to divert the flow of fluid from the inlet duct to the outlet duct without the fluid flowing into the pumping unit. The multifunction valve comprises a valve body that defines an inner bypass channel in which a shutter element is axially movable, an actuator member operatively associated with the shutter element and configured to move it from a closing position to an opening position of the bypass channel, and an elastic contrast element operatively associated with the shutter element and configured to keep it in the first closing position of the bypass channel when such shutter element is not actuated by the actuator member. The actuator member consists of a bias spring manufactured with a shape memory alloy, configured to move the shutter element from the first closing position to the second opening position of the bypass channel when a predefined temperature value is reached.