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.

A method actuates a hydraulic system for an actuation device of a motor vehicle. The hydraulic system has a pump and multiple valves which are each arranged between a system rail connected to a pump outlet and a hydraulic consumer. The pump is switched between a normal operation and an enhanced operation according to an existing total energy demand of the hydraulic consumers. In normal operation, the pump is driven when the system pressure is below a lower pressure threshold and switched off when the system pressure is above an upper pressure threshold. In the enhanced operation, the pump is permanently driven and each of the valves is operated according to an individual energy demand of the respective hydraulic consumer as soon as the system pressure achieves or exceeds a threshold value.

The present disclosure describes a hydraulic control system comprising a first pressure chamber and a second pressure chamber, each pressure chamber configured to receive a hydraulic fluid, a first movable member configured to assume a position depending on a hydraulic pressure of the hydraulic fluid in the first pressure chamber and a second movable member configured to assume a position depending on a hydraulic pressure of the hydraulic fluid in the second pressure chamber, a hydraulic command circuit configured to provide the hydraulic fluid and to control the hydraulic pressure of the hydraulic fluid in the first pressure chamber and/or the second pressure chamber, having a switchable valve in fluid communication with the first pressure chamber, wherein the switchable valve is configured to be pilotable depending on the hydraulic pressure of the hydraulic fluid in the second pressure chamber.

A line pressure control method for a double clutch transmission (DCT) includes estimating a line pressure, which decreases with stoppage of an electric oil pump, based on a linear regression model using state variables of the DCT that are related to a line pressure change, and driving the electric oil pump when the line pressure estimated based on the linear regression model reaches a predetermined lower limit.

A method for controlling a friction clutch actuated by an actuation system using an actuation pressure ambiguously applied along an actuation path includes providing the friction clutch and the actuation system, detecting a time curve of an actuation processes of the friction clutch, and comparing the time curve with the actuation pressure to ascertain an unambiguous friction clutch actuation path. The method may also include using the time curve to determine whether the friction clutch is in an opening state or a closing state and whether the actuation pressure is applied to an opened friction clutch actuation path or a closed friction clutch actuation path, and starting from a set actuation pressure, carrying out a directional control of the friction clutch by specifying the actuation pressure.

The present disclosure describes a hydraulic control system comprising a first pressure chamber and a second pressure chamber, each pressure chamber configured to receive a hydraulic fluid, a first movable member configured to assume a position depending on a hydraulic pressure of the hydraulic fluid in the first pressure chamber and a second movable member configured to assume a position depending on a hydraulic pressure of the hydraulic fluid in the second pressure chamber, a hydraulic command circuit configured to provide the hydraulic fluid and to control the hydraulic pressure of the hydraulic fluid in the first pressure chamber and/or the second pressure chamber, having a switchable valve in fluid communication with the first pressure chamber, wherein the switchable valve is configured to be pilotable depending on the hydraulic pressure of the hydraulic fluid in the second pressure chamber.

A hydraulic circuit for a vehicle driving device includes an oil pump, a clutch oil passage, a cooling oil passage, a pressure regulating valve, and a shift valve. The cooling oil passage guides oil to a cooled portion of a vehicle. Supply of oil to the clutch oil passage and the cooling oil passage is switched by switching of the pressure regulating valve and the shift valve. The cooling oil passage includes: a shaft center cooling oil passage which supplies cooling oil to a shaft center of a rotation shaft of an electric motor mounted on the vehicle; and a cooling oil passage shift valve which switches presence/absence of supply of oil to the shaft center cooling oil passage.

A driving force distributing device includes a single pump for supplying control hydraulic pressure to each of first and second hydraulic clutches, an electric motor for driving the pump, a flow rate variable mechanism for changing a ratio of flow rate of hydraulic fluid supplied to each of the first and second hydraulic clutches and a controlling means for controlling the electric motor and the flow rate variable mechanism. The driving force distributing device can variably control a flow rate of hydraulic fluid supplied to first and second hydraulic clutches based on changing a ratio of flow rate of hydraulic fluid supplied to the first and second hydraulic clutches in the flow rate variable mechanism and a control of changing rotational speed of the pump using the motor.

A clutch mechanism designed to be installed between an engine and a motor vehicle transmission, wherein the clutch mechanism includes at least one cooling duct arranged to make a cooling fluid circulate toward the clutch, wherein each cooling duct includes an axially extending part and at least one radially extending part, the axially extending part of each cooling duct is situated radially between a transmission shaft and an interior face of the clutch support, and at least one radially extending part of each cooling duct is situated axially between the support bearing and the output hub.

The invention relates to a hydraulic circuit (1) of a torque transmission device, wherein at least two, in particular closed in a non-actuated state (normally closed), clutches (2, 3) of the torque transmission device can be element (12, 13) of the hydraulic circuit, wherein in a clutch opening state, every clutch valve element (12, 13) is connected to a high-pressure line (30) that is applied with the pressure of a high-pressure hydraulic accumulator (31) and/or generator (32), by means of a pressurisation line (22, 23) for the deflection of the clutch (2, 3), and in a closing state, same is connected to a low-pressure tank (40) by means of a tank line (42, 43, 44, 45, 46, 47, 48, 49) for releasing a deflection pressure, and wherein the tank lines (42, 43, 44, 45, 46, 47, 48, 49) of the clutch valve elements (12, 33) are guided to a safety valve (50), in particular by means of a common collection tank line (41), which safety valve can be switched in such a way that the tank lines (42, 43, 44, 45, 46, 47, 48, 49) can be applied with the pressure of the high-pressure line (30).