Abstract: A transmission control circuit for controlling a system pressure provided by a pressure pump in a transmission. The circuit includes a pressure control valve and an electronic control unit. Load states and operating states of the working machine can be detected by the control unit and transmission input torque limits associated with the load states and state values representing at least one first operating state and state values representing at least one second operating state are stored therein. The first operating state corresponds with the maximum system pressure and the second operating state corresponds with a reduced system pressure compared to the maximum system pressure. The circuit includes a pressure limiting valve activated by the control unit to overrule the pressure control valve in order to variably set the reduced system pressure.

Abstract: A transmission control circuit for controlling a system pressure provided by a pressure pump in a transmission. The circuit includes a pressure control valve and an electronic control unit. Load states and operating states of the working machine can be detected by the control unit and transmission input torque limits associated with the load states and state values representing at least one first operating state and state values representing at least one second operating state are stored therein. The first operating state corresponds with the maximum system pressure and the second operating state corresponds with a reduced system pressure compared to the maximum system pressure. The circuit includes a pressure limiting valve activated by the control unit to overrule the pressure control valve in order to variably set the reduced system pressure.

Abstract: The cooling of a hydraulically-operated wet clutch with coolant is primarily required during the slippage phase when the linings are heated by the slip, that is, when the torque transmitted by the clutch is less than the torque delivered by the engine. A coolant flow control is provided in which a coolant control valve is controlled in such a way that it interrupts the coolant flow to the clutch during operation with clutch engaged or disengaged and opens the coolant flow to the clutch during the engagement process of the clutch and, if required, for a predetermined time interval following the engagement process. However, the coolant control valve only opens the coolant flow to the clutch during the disengagement process if the slippage phase during disengagement lasts longer than a predetermined second time interval.