A transmission includes an electro-hydraulic controller that includes redundancy in the hydraulic circuit that permits single fault failures to be compensated for by changing the flow path of hydraulic fluid to bypass the single fault failure. The redundancy results in the ability of the transmission to maintain full operation in all modes.

A transmission includes an electro-hydraulic controller that includes redundancy in the hydraulic circuit that permits single fault failures to be compensated for by changing the flow path of hydraulic fluid to bypass the single fault failure. The redundancy results in the ability of the transmission to maintain full operation in all modes.

A dual-clutch transmission includes a hydraulic system for actuating hydraulic cylinders of the clutches and the shifting elements. The hydraulic system has a pressure accumulator providing an accumulated pressure in the hydraulic system, and control valves actuatable by a control unit and respectively arranged in pressure lines routed to the hydraulic cylinders of the clutches to adjust the hydraulic pressure applied to the clutches. Pressure sensors associated with the control unit detect the hydraulic pressure. The control unit activates a pressure reduction mode when detecting a long vehicle downtime, and the accumulated pressure can be reduced in the pressure reduction mode, in which the control unit continuously opens the control valve associated with one clutch. Additionally, the pressure sensor associated with the first clutch together with the control unit is integrated into a control circuit in which the first pressure sensor assumes the detection of the actual accumulated pressure value.

A hydraulic controller for an automatic transmission of a motor vehicle includes at least one gear shift piston-cylinder unit having a gear shift piston for actuating a shifting element in the form of a multi-plate clutch, and a gear shift pressure chamber in which an actuating pressure may be built up by supplying operating fluid. The gear shift piston-cylinder unit has a centrifugal oil chamber that is separated from the gear shift pressure chamber by a gear shift piston. Operating fluid may be supplied to the centrifugal oil chamber via a centrifugal oil line supplied by a first supply line. The hydraulic controller has a second supply line for supplying operating fluid to the centrifugal oil line. The second supply line may be closed and opened by a centrifugal oil valve.

Apparatus, system and method for providing supplementary power. A vessel is configured to receive and contain hydraulic fluid, where the vessel includes a piston configured within the vessel to be vertically displaced by the hydraulic fluid and provide pressure from the weight of the piston to a fluid supply line. A solenoid valve is operatively coupled to the fluid supply line; and connected to a flywheel power supply that includes a flywheel and a hydraulic drive adapter, wherein the hydraulic drive adapter is operatively coupled to the solenoid valve via the fluid supply line. A signal is received indicating a power outage, where the solenoid valve is further configured to open in response to the signal and provide the hydraulic fluid pressurized by the piston to the hydraulic drive adapter and causes the flywheel to operate and provide the supplementary power.

A hydraulic system for an automatic gearbox for a motor vehicle, includes a high-pressure circuit which includes a pressure accumulator, at least one clutch and actuators, and a low-pressure circuit for cooling the clutch, the high-pressure circuit and the low-pressure circuit each containing a hydraulic cooling pump and a hydraulic charging pump that can be driven by a shared electric motor; and a controller which, when it is detected that the pressure accumulator needs to be charged, controls the electric motor to run at a charging setpoint speed, and/or, when it is detected that cooling is needed or another need exists, controls the electric motor to run at a cooling setpoint speed or another setpoint speed. When the pressure accumulator does not need to be charged and there is no need for cooling and no other need, the controller reduces the setpoint speed to zero for a specified period. At the end of the period the controller controls the electric motor to run at least at the test speed.

In one instance, disclosed herein is a pressure modulating clutch control assembly that includes: a valve assembly configured to apply a clutch pressure to a clutch device; a pressure modulation assembly in fluid communication with the valve assembly and configured to control a maximum pressure level that the clutch pressure reaches; and a modular relief valve in fluid communication with the valve assembly and the pressure modulation assembly, the modular relief valve forming part of a hydraulic feedback loop between the valve assembly and the pressure modulation assembly, wherein the hydraulic feedback loop is configured such that an increase in a modulation pressure of a pressurized fluid within the pressure modulation assembly causes a corresponding increase in the clutch pressure until the clutch pressure reaches the maximum pressure level.

In one instance, disclosed herein is a pressure modulating clutch control assembly that includes: a valve assembly configured to apply a clutch pressure to a clutch device; a pressure modulation assembly in fluid communication with the valve assembly and configured to control a maximum pressure level that the clutch pressure reaches; and a modular relief valve in fluid communication with the valve assembly and the pressure modulation assembly, the modular relief valve forming part of a hydraulic feedback loop between the valve assembly and the pressure modulation assembly, wherein the hydraulic feedback loop is configured such that an increase in a modulation pressure of a pressurized fluid within the pressure modulation assembly causes a corresponding increase in the clutch pressure until the clutch pressure reaches the maximum pressure level.