Abstract: The invention relates to a friction clutch having a single-acting actuator which is a piston-cylinder unit and is connected in a controllable fashion to a pressurized fluid source. In order to be able to carry out a fast pilot stroke up to the point at which the clutch makes contact, the piston-cylinder unit has a stepped piston whose first step of small diameter delimits, by means of its cylinder, a first pressure space, and whose second step of relatively large diameter delimits, by means of its cylinder, a second pressure space, a pressure line being connected to the first pressure space and, by means of a first non-return valve which opens at a certain pressure, to the second pressure space, and it also being possible for the second pressure space to be connected via a discharge line and a suction line, which contains a second non-return valve, to the fluid reservoir. The invention also relates to a drive device having clutches of said type.

Abstract: The invention relates to a friction clutch having a single-acting actuator which is a piston-cylinder unit and is connected in a controllable fashion to a pressurized fluid source. In order to be able to carry out a fast pilot stroke up to the point at which the clutch makes contact, the piston-cylinder unit has a stepped piston whose first step of small diameter delimits, by means of its cylinder, a first pressure space, and whose second step of relatively large diameter delimits, by means of its cylinder, a second pressure space, a pressure line being connected to the first pressure space and, by means of a first non-return valve which opens at a certain pressure, to the second pressure space, and it also being possible for the second pressure space to be connected via a discharge line and a suction line, which contains a second non-return valve, to the fluid reservoir. The invention also relates to a drive device having clutches of said type.

Abstract: An actuator with a simple function for the control of a friction clutch in the drive train of a motor vehicle having a cylinder/piston unit for generating the contact pressure of the clutch should be fast, inherently safe and nevertheless simple and inexpensive. For this purpose, a controllable pump (3) generates a pressure medium and makes it available to the cylinder/piston unit (1) via a self-regulating valve unit (2). A dump valve (8) consists of a sleeve (10) and a spring-assisted slide (12) therein. The sleeve has a first opening (11), through which the pressure medium can flow from the cylinder/piston unit (1). The slide (12) exposes the opening (11) in a first position and conceals the opening of a second position. The clutch is controlled in this way by actuating the electric motor.

Abstract: An actuator with a simple function for the control of a friction clutch in the drive train of a motor vehicle having a cylinder/piston unit for generating the contact pressure of the clutch should be fast, inherently safe and nevertheless simple and inexpensive. For this purpose, a controllable pump (3) generates a pressure medium and makes it available to the cylinder/piston unit (1) via a self-regulating valve unit (2). A dump valve (8) consists of a sleeve (10) and a spring-assisted slide (12) therein. The sleeve has a first opening (11), through which the pressure medium can flow from the cylinder/piston unit (1). The slide (12) exposes the opening (11) in a first position and conceals the opening of a second position. The clutch is controlled in this way by actuating the electric motor.

Abstract: A transfer case having a clutch unit, to produce a connection between a first output shaft and a second output shaft includes a claw clutch associated with a synchronizer clutch which comprises a first synchronizer part, which is connected in a rotationally fixed manner to the first output shaft, and a second sychronizer part, which is connected in a rotationally fixed manner to a first clutch part.

Abstract: A transfer case having a clutch unit, to produce a connection between a first output shaft and a second output shaft includes a claw clutch associated with a synchronizer clutch which comprises a first synchronizer part, which is connected in a rotationally fixed manner to the first output shaft, and a second sychronizer part, which is connected in a rotationally fixed manner to a first clutch part.