A parking lock actuation system for an automatic gearbox of a vehicle is described. The parking lock actuation system has a closed state in which a piston rod of a hydraulic cylinder is in a first position urging a locking pawl to block a gear of the automatic gearbox, and an open state in which the piston rod of the hydraulic cylinder is in a second position preventing the locking pawl from engaging the gear of the automatic gearbox. The parking lock actuation system further includes a first hydraulic valve being connected to a first hydraulic line, to a pressure source and a substantially non-pressurized reservoir, and a second hydraulic valve being connected to a first volume of the hydraulic cylinder, to the first hydraulic line and a non-pressurized reservoir. The first hydraulic valve includes an electrical actuator.

A method for controlling a hydraulic unit with a rotational-speed-controlled pump which, at an outlet side, provides at least two fluid flows in a manner switched by means of switching valves actuating at least one slave cylinder and for providing a volume flow which is controlled based on a rotational speed of the pump. To set the volume flow, an efficiency of the pump is calculated base on a comparison of a known slave cylinder volume of the at least one slave cylinder and a quantity of fluid of the pump for the filling of the at least one slave cylinder.

The present disclosure provides an oil pressure supply system of an automatic transmission for a vehicle. The system may include: a mechanical oil pump; a line regulator valve configured to stably control the oil pressure supplied through the line pressure path and to supply the oil pressure to a first path; a torque converter control valve configured to control the oil pressure supplied through the first path and to supply the oil pressure to a second path and a third path; a torque converter lockup clutch control valve; an electric oil pump; a switch valve disposed on the seventh path and configured to open and close the oil pressure supplied to an eighth path; and a flow control valve configured to control a portion of the oil pressure supplied to the eighth path and to supply the portion of the oil pressure to the cooling/lubricating unit through a ninth path.

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 fluid assembly in a hydraulic circuit, comprising one or more reservoirs configured to store fluid. The fluid assembly also includes a pump configured to transport the fluid in the hydraulic circuit and actuate a load from a transmission of a motor vehicle, a pressure accumulator configured to collect pressure built up by the pump and actuate the load, and a valve system configured to allow fluid communication of the load with the pump.

The present disclosure provides an oil pressure supply system of an automatic transmission for a vehicle. The system may include: a mechanical oil pump; a line regulator valve configured to stably control the oil pressure supplied through the line pressure path and to supply the oil pressure to a first path; a torque converter control valve configured to control the oil pressure supplied through the first path and to supply the oil pressure to a second path and a third path; a torque converter lockup clutch control valve; an electric oil pump; a switch valve disposed on the seventh path and configured to open and close the oil pressure supplied to an eighth path; and a flow control valve configured to control a portion of the oil pressure supplied to the eighth path and to supply the portion of the oil pressure to the cooling/lubricating unit through a ninth path.

A parking lock actuation system for an automatic gearbox of a vehicle is described. The parking lock actuation system has a closed state in which a piston rod of a hydraulic cylinder is in a first position urging a locking pawl to block a gear of the automatic gearbox, and an open state in which the piston rod of the hydraulic cylinder is in a second position preventing the locking pawl from engaging the gear of the automatic gearbox. The parking lock actuation system further includes a first hydraulic valve being connected to a first hydraulic line, to a pressure source and a substantially non-pressurized reservoir, and a second hydraulic valve being connected to a first volume of the hydraulic cylinder, to the first hydraulic line and a non-pressurized reservoir. The first hydraulic valve includes an electrical actuator.

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.

A fluid powered circuit for a gearbox and a method for protecting a gearbox are disclosed. The fluid powered circuit includes a control circuit operatively connected to a clutch engagement circuit. The fluid powered circuit is selectively operable to either flow a fluid from a fluid supply source to the clutch or vent the fluid to the atmosphere. The method for protecting the gearbox includes flowing the fluid from the fluid supply source to the fluid powered circuit, measuring the speed of the shaft, measuring the pressure of the fluid entering the clutch engagement circuit, and flowing the fluid from the fluid powered circuit to the clutch upon detecting one or more conditions.