Abstract: A clutch device for a motor vehicle has friction elements around which coolant flows and which, by way of a piston, can be pressed against one another for torque transmission. The first piston side is acted on with operating pressure, and the second piston side is acted on with coolant pressure. A valve, by which the operating pressure can be set, and a device which makes a reaction of the coolant pressure on the operating pressure possible are provided. The device is designed as a hydraulic resistance cascade and is connected between coolant supply and coolant return lines of the friction elements. A return pressure line branches off in the center of the hydraulic resistance cascade and is connected to the valve.

Abstract: A clutch device for a motor vehicle has friction elements around which coolant flows and which, by way of a piston, can be pressed against one another for torque transmission. The first piston side is acted on with operating pressure, and the second piston side is acted on with coolant pressure. A valve, by which the operating pressure can be set, and a device which makes a reaction of the coolant pressure on the operating pressure possible are provided. The device is designed as a hydraulic resistance cascade and is connected between coolant supply and coolant return lines of the friction elements. A return pressure line branches off in the center of the hydraulic resistance cascade and is connected to the valve.

Abstract: In a method for controlling the operating temperature of a hydraulic operating medium for a drive unit of a vehicle in a selected range, the operating temperature is controlled by controlling the volume flow of the operating medium for a heat exchange between the operating medium and a secondary heat transfer medium flow medium to a predetermined desired value as a function of the actual value of the operating temperature and as a function of at least one other vehicle parameter, by which a certain temperature influencing effect on the operating medium can be provided. The selected range of the operating temperature includes both the temperature values occurring in the warm-up phase of the drive unit and temperature values, which are substantially higher than the desired value.

Abstract: A system and method serve for optimizing the efficiency of an oil supply having at least two different oil pressure levels. The system has at least two feed devices and at least one control slide with at least two narrowed sections. Each of the narrowed sections is assigned one of the feed devices. Depending on the position of the narrowed sections in the control slide, the respective volume flows are automatically divided into the at least two pressure levels for each of the feed devices as a function of the oil requirement in the respective pressure level.

Abstract: In a method for controlling the operating temperature of a hydraulic operating medium for a drive unit of a vehicle in a selected range, the operating temperature is controlled by controlling the volume flow of the operating medium for a heat exchange between the operating medium and a secondary heat transfer medium flow medium to a predetermined desired value as a function of the actual value of the operating temperature and as a function of at least one other vehicle parameter, by which a certain temperature influencing effect on the operating medium can be provided. The selected range of the operating temperature includes both the temperature values occurring in the warm-up phase of the drive unit and temperature values, which are substantially higher than the desired value.