Abstract: A method and device for actuating a shift element of an automatic transmission having a start-stop function and a pressure medium pump driven by an internal combustion engine. The shifting elements are clutches or brakes that can be actuated by a piston which is actuated for engagement via pressure supplied to a pressure space. The pressure space is depressurized when the engine stops. To enhance start-stop operation, the shifting elements comprise an additional pressure space that acts, in opposition to the pressure space acting in the engaging direction, as a controllable restoring mechanism which can be rendered inactive, if desired. If the engine stops and the automatic start-stop function is activated, the additional pressure spaces, acting in the restoring direction, are depressurized before the pressure drop in the pressure spaces, acting in the engaging direction, of the pistons, but are otherwise permanently pressurized during driving operation.

Abstract: A method for actuating a shift element of an automatic transmission having a start-stop function and a pressure medium pump driven by an internal combustion engine. The shifting elements are clutches or brakes that can be actuated by a piston which is actuated for engagement via pressure supplied to a pressure space. The pressure space is depressurized when the engine stops. To enhance start-stop operation, the shifting elements comprise an additional pressure space that acts, in opposition to the pressure space acting in the engaging direction, as a controllable restoring mechanism which can be rendered inactive, if desired. If the engine stops and the automatic start-stop function is activated, the additional pressure spaces, acting in the restoring direction, are depressurized before the pressure drop in the pressure spaces, acting in the engaging direction, of the pistons, but are otherwise permanently pressurized during driving operation.

Abstract: A method for actuating a shift element of an automatic transmission having a start-stop function and a pressure medium pump driven by an internal combustion engine. The shifting elements are clutches or brakes that can be actuated by a piston which is actuated for engagement via pressure supplied to a pressure space. The pressure space is depressurized when the engine stops. To enhance start-stop operation, the shifting elements comprise an additional pressure space that acts, in opposition to the pressure space acting in the engaging direction, as a controllable restoring mechanism which can be rendered inactive, if desired. If the engine stops and the automatic start-stop function is activated, the additional pressure spaces, acting in the restoring direction, are depressurized before the pressure drop in the pressure spaces, acting in the engaging direction, of the pistons, but are otherwise permanently pressurized during driving operation.

Abstract: A device for controlling a rotating shifting element of an automatic transmission for a start/stop operation. The shifting element is actuated by an axially moving piston which is biased, in a disengaging direction, by a spring and biased, in an engaging direction, by hydraulic pressure supplied to a pressure space. At least one spring-loaded latch, which is able to move in the radial direction, is arranged in the pressure space. The spring-loaded latch, when the combustion engine is operating, rotates with the piston and acts upon the piston such that if the engine stops, the previously engaged shifting element is locked by spring force and, as the pressure decreases, the shifting element disengages, at most only slightly, and when the engine is re-started, the locking action is again released by centrifugal force, in opposition to the spring force, so that the piston remains engaged during the hydraulic pressure build-up in the pressure chamber.

Abstract: A method and device for actuating a shift element of an automatic transmission having a start-stop function and a pressure medium pump driven by an internal combustion engine. The shifting elements are clutches or brakes that can be actuated by a piston which is actuated for engagement via pressure supplied to a pressure space. The pressure space is depressurized when the engine stops. To enhance start-stop operation, the shifting elements comprise an additional pressure space that acts, in opposition to the pressure space acting in the engaging direction, as a controllable restoring mechanism which can be rendered inactive, if desired. If the engine stops and the automatic start-stop function is activated, the additional pressure spaces, acting in the restoring direction, are depressurized before the pressure drop in the pressure spaces, acting in the engaging direction, of the pistons, but are otherwise permanently pressurized during driving operation.

Abstract: A device for controlling a rotating shifting element of an automatic transmission for a start/stop operation. The shifting element is actuated by an axially moving piston which is biased, in a disengaging direction, by a spring and biased, in an engaging direction, by hydraulic pressure supplied to a pressure space. At least one spring-loaded latch, which able to move in the radial direction, is arranged in the pressure space. The spring-loaded latch, when the combustion engine is running, rotates with the piston and acts upon the piston such that if the engine stops, the previously engaged shifting element is locked by spring force and, as the pressure decreases, the shifting element disengages slightly, at most only slightly, and when the engine is re-started, the locking action is again released by centrifugal force, in opposition to the spring force, so that the piston remains engaged by the hydraulic pressure build-up in the pressure chamber.

Abstract: A drive device (2) for the oil pump (6) of a motor vehicle automatic transmission, in which the oil pump (6) on the one hand can be coupled to the drive motor by way of an overrunning clutch (34) and on the other hand is drivingly connected to an auxiliary electric motor (22), which is powered by the on-board power supply of the motor vehicle. The electric motor (22) is arranged outside of the pump housing (8) and is drivingly connected to a driven pump impeller wheel (ring gear 10) that is arranged in the pump housing via a non-rotatable connection.

Abstract: A drive device (2) for the oil pump (6) of a motor vehicle automatic transmission, in which the oil pump (6) on the one hand can be coupled to the drive motor by way of an overrunning clutch (34) and on the other hand is drivingly connected to an auxiliary electric motor (22), which is powered by the on-board power supply of the motor vehicle. The electric motor (22) is arranged outside of the pump housing (8) and is drivingly connected to a driven pump impeller wheel (ring gear 10) that is arranged in the pump housing via a non-rotatable connection.

Abstract: The invention concerns a drive device (7) with variable transmission ratio for driving an auxiliary aggregate of a motor vehicle. A belt pulley (11) of the drive device (7) has a chamber (38) connected to a reservoir (30) of a hydraulic medium. The centrifugal action of the hydraulic medium contained in the chamber (38) is used to change the speed of the driven shaft (13). By applying a supporting pressure to the chamber (38), it is possible additionally to vary the output speed of the drive device (7).

Abstract: Pressure-medium actuated shifting arrangement for a gear transmission, primarily for a multispeed transmission, in which the speed selection lever performs a movement in accordance with a double H shifting configuration. Within the reach of the driver, in a shift console another transmission shaft is mounted, which is displaced by the speed selection lever for path selection and twisted for gear shifting. The transmission shaft has also cams and valves cooperating with a pressure-medium source over the selection cylinder and shift cylinder mounted to the gear box which actuate a gear-shift-lever shaft, whereby not only the desired shift couplings are put into effect, but also feedback information about the shifting situation in the transmission perceptible by the driver is conveyed.