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.

A clutch latching system is provided for latching and draining a torque transmitting mechanism. The latching clutch control system may include a latching valve, a release valve, and an accumulator. The clutch latching system may include a clutch feed channel configured to provide hydraulic fluid from a pressurized source to a torque transmitting device when the torque transmitting device is engaged and the engine is running. A latching valve connects the clutch feed channel to the torque transmitting device. The latching valve is configured to selectively trap pressurized hydraulic fluid within the torque transmitting device. A hydraulic pressure storage circuit configured to selectively provide pressurized hydraulic fluid to the latching valve to unlatch the latching valve. A multiple speed transmission is also provided.

An internal combustion engine which can be miniaturized, even where it includes an oil filter between a hydraulic clutch and an oil pump, without significantly increasing the length of an oil passage for the hydraulic clutch, the oil pump and a hydraulic pressure adjustment apparatus. A second oil filter is provided on an oil pan at a lower portion of the internal combustion engine so as to be disposed at a position at which the second oil filter does not overlap with any of a controlling oil pump and a hydraulic pressure adjustment apparatus as viewed in side elevation and which is lower than those of the oil pump and the hydraulic pressure adjustment apparatus.

A hydraulic circuit includes a clutch actuator operatively associated with a clutch that may be disposed in a transmission. A hydraulic fluid source supplies pressurized hydraulic fluid for the clutch actuator. To measure the filling rate of the hydraulic actuator, a reference actuator having a predetermined filling rate is disposed in parallel with the hydraulic actuator and in fluid communication with the hydraulic fluid source. If hydraulic pressure associated with the reference actuator does not correspond to the hydraulic pressure associated with the clutch actuator, a compensation valve can appropriately respond by selectively directing hydraulic fluid to or from the clutch actuator. In a further embodiment, the reference actuator and compensation valve may be replaced with an electrohydraulic valve utilizing feedback from the hydraulic pressure present at the inlet of the clutch actuator.

The invention relates to an actuating device for actuating a clutch and/or a transmission of a motor vehicle, including a pump having two fluid connections and including a movable actuating element fluidically connected to a first fluid connection of the pump, wherein the pump is designed such that in a first pump position, in which the pump is driven in a first direction of rotation, for extending the actuating element the pump conveys a pressure fluid in a first conveying direction from a second fluid connection to the first fluid connection, wherein the pump is configured as a variable displacement pump which is reversible with regard to the conveying direction of the pump, wherein the pump is designed such that after it has been moved into a second pump position, in which the pump is driven in the first direction of rotation, for retracting the actuating element the pump conveys a pressure fluid in a second conveying direction, opposite the first conveying direction, from the first fluid connection to the second fluid connection. The invention further relates to a clutch and to a transmission system having such an actuating device.

A power unit includes a transmission adapted to transmit rotational power from a crankshaft to a drive axle, with speed change. The transmission has an input shaft rotatably supported on a crankcase. A hydraulic clutch, configured to be selectively engaged and disengaged, is disposed coaxially with the input shaft. A clutch cover covering the hydraulic clutch is connected to the crankcase. A clutch actuator, which controls switching between engagement and disengagement of the hydraulic clutch, and an actuator cover, which covers the clutch actuator in a liquid-tight manner, are mounted to an outer surface of the clutch cover. An oil temperature sensor is mounted to the actuator cover, and is provided for detecting a temperature of oil in an oil chamber, formed between the clutch cover and the actuator cover.

A system is provided for latching and draining a torque transmitting device. The system may include a clutch feed channel having an inlet portion and a clutch portion. The inlet portion is configured to provide hydraulic fluid from a pressurized source to the clutch portion. The clutch portion is configured to provide hydraulic fluid to a torque transmitting device. An inlet valve connects the inlet portion of the clutch feed channel to the clutch portion of the clutch feed channel. The inlet valve is configured to open to allow the hydraulic fluid to flow from the inlet portion to the clutch portion when the torque transmitting device is engaged. The inlet valve is configured to close and to trap hydraulic fluid within the torque transmitting device when the torque transmitting device is not actively pressurized. A multispeed transmission is also provided.