Abstract: A hydraulic control device for an automatic transmission including a valve device. The valve device comprising a switching valve, featuring a switching component and a check valve. The switching valve is formed in a housing and is hydraulically connected to a first pressure adjusting device and a second pressure adjusting device along with a shift element for transferring a certain torque. The switching valve is formed as a directional seat valve.

Abstract: A hydraulic control device for an automatic transmission featuring at least one valve device (1), the valve device (1) comprising a switching valve (10), featuring a switching component (11) and a check valve (20), whereas the switching valve (10) is formed in a housing (30) and is hydraulically connected to a first pressure adjusting device (HCU) and a second pressure adjusting device (EDS) along with a shift element (K) for transferring a certain torque, whereas the switching valve (10) is formed as a directional seat valve.

Abstract: The invention concerns a hydraulic circuit (3) for oil supply of an automatic transmission, in particular a stepped automatic transmission for motor vehicles, consisting of a low pressure circuit (4) for delivering a first volume stream V1 at a first pressure level P1 and a high pressure circuit (5) for delivering a second volume stream V2 at a second, higher pressure P2. It is proposed that when necessary the first pressure level P1 of the first volume stream V1 can be modulated to the higher pressure P2 and the two volume streams V1, V2 can be summed at the same pressure level P2.

Abstract: Described is a radial piston pump with a pump housing (3), which has a plurality of cylinder bores (5) arrayed in star shape around a cam (4), for the reception of pistons (6) and possesses inlet (7) and outlet (8) when penetrate to each cylinder inner chamber (9) with a therein compressible working volume. In accord with the invention, each cylinder inner chamber (9) is provided with at least one relief opening, which connects the working volumes during a compression stroke of the piston (6) with a space of lesser pressure for the reduction of the pressure gradient and also thereby reducing the noise of the pump.

Abstract: Described is a radial piston pump with a pump housing (3), which has a plurality of cylinder bores (5) arrayed in star shape around a cam (4), for the reception of pistons (6) and possesses inlet (7) and outlet (8) when penetrate to each cylinder inner chamber (9) with a therein compressible working volume. In accord with the invention, each cylinder inner chamber (9) is provided with at least one relief opening, which connects the working volumes during a compression stroke of the piston (6) with a space of lesser pressure for the reduction of the pressure gradient and also thereby reducing the noise of the pump.