Disclosed is an actuator for a dual clutch. The actuator may be applied to a dual clutch including: a first clutch which is configured to selectively transmit rotational power of an input shaft to a first output shaft; a second clutch which is configured to selectively transmit the rotational power of the input shaft to a second output shaft; a first piston which operates the first clutch while being selectively and axially moved by axial force; and a second piston which operates the second clutch while being selectively and axially moved by the axial force. The actuator may be configured to transmit the axial force to the first piston or the second piston.

The actuator may have a first operating piston and a second operating piston which are provided in an actuator housing. The first operating piston may transmit the axial force to the first piston, and the second operating piston may transmit the axial force to the second piston.

A hydraulic control system of double piston clutch device configured for an automatic transmission, which includes clutch drum connected to one rotation element, a clutch configured in the clutch drum and configured to transmit rotation power in connection with another rotation element through a clutch hub, and a double piston in which first and second pistons are disposed in series to operate the clutch by hydraulic pressure while a front end is disposed to correspond to the clutch, may include a first hydraulic chamber formed between the first piston and the clutch drum to receive the hydraulic pressure through a first passage hole in a sealed state; and a second hydraulic chamber formed between the first and second pistons to receive the hydraulic pressure through a second passage hole in the sealed state and the hydraulic pressure separately controlled is supplied to the first and second hydraulic chambers, respectively.

A clutch control hydraulic circuit includes first and second solenoid valves connected to a control unit, the first solenoid valve is provided between a first hydraulic pathway and a downstream junction hydraulic pathway normally switches to an open state when not energized, and switches to a closed state when energized; and the second solenoid valve is provided between a second hydraulic pathway and the junction hydraulic pathway, switches to a closed state when not energized, and switches to an open state when energized. The first solenoid valve maintains its closed state when switched to a non-energized state from an energized state while pressure of the junction hydraulic pathway is higher than that of the first hydraulic pathway, and when the first solenoid valve is thus closed in its non-energized state, pressurizing the upstream side hydraulic pathway by operation of a clutch lever opens the first solenoid valve.

The invention relates to a hydraulic assembly for driving a friction clutch, comprising a hydraulically driveable actuator cylinder, a pump driving the actuator cylinder, wherein the actuator cylinder has a working piston with a working chamber and the working piston moveably arranged in the working chamber divides said working chamber into a main chamber and an auxiliary chamber, at least one control valve which is designed as a multi-port valve and arranged in the line path between the actuator cylinder and the pump, wherein a first supply line leads from the pump to the control valve, whereby a line path is created via a second supply line in a first valve position of the control valve, which leads to the main chamber of the actuator cylinder. In addition, in a second valve position of the control valve, the auxiliary chamber of the working chamber can be fluidically connected to the line path of the first and second supply lines via a first discharge line, while simultaneously, in the second valve position, the main chamber is connected via the first and second supply lines by means of the pump.

Disclosed is a hydraulic pressure supply system of a dual clutch transmission for a vehicle in which by independently configuring a low pressure supply route and a high pressure supply route, the hydraulic pressure supply system can enable a low hydraulic pressure that is generated in a hydraulic pump for a low pressure to be supplied to a gear lubrication device and a clutch cooling/lubrication device and enable a low hydraulic pressure that is generated in a hydraulic pump for a high pressure to be supplied to a gear control device and a clutch control device.

Disclosed is a motorcycle clutch actuator, with hydraulically linked foot clutch lever and hand clutch lever, to be installed on motorcycles made with a hand activated gear selection lever or on motorcycles to be converted from a conventional configuration of hand activated clutch and foot activated gear selection lever, to a configuration of foot activated clutch and hand activated gear selection lever, providing optimal clutch control with either a foot clutch lever or a hand clutch lever, by means of innovative hydraulic and mechanical control linkage, releasing the rider's foot from the foot clutch lever, while holding the clutch in the disengaged position with a hand clutch lever, as the motorcycle is running while in gear, thereby enabling the rider to balance the motorcycle with both feet while modulating the clutch with the hand clutch lever.

A method of regulating a clutch assembly that has a set of clutch plates and a clutch piston with a fluid seal in an automatic transmission that includes a hydraulic circuit is disclosed. The method includes commanding the hydraulic circuit via the controller to apply a first hydraulic force to the clutch piston to displace the clutch piston relative to the set of clutch plates in order to affect a shift between speed-ratios in the transmission. The method also includes determining a drag force of the fluid seal. The method also includes determining a velocity of the displaced clutch piston that results from the drag force of the fluid seal acting counter to the displacement of the clutch piston. The method additionally includes regulating the clutch assembly to compensate for the determined drag force of the fluid seal acting counter to the displacement of the clutch piston.