Abstract: A speed-difference-dependent hydraulic clutch comprises a drive housing (11), which rotates in a housing (20), a first shaft (21) which can be connected in a rotationally fixed manner to the drive housing, a second shaft (22) which is connected in a rotationally fixed manner to the drive housing, and furthermore a hydrostatic displacement machine (1), a friction clutch (12) for connecting the first shaft (21) to the drive housing (11), and a piston (10) for acting on the friction clutch (12), the drive housing (11) having a pressure space (9) and where a pressure is produced in the pressure space (9) when a difference in speed occurs in the pressure space (9), this pressure giving rise to action upon the friction clutch (12), and a passage (13) leading from the pressure space to a control valve which opens up the route to a space of lower pressure in a controlled manner.

Abstract: A speed-difference-dependent hydraulic clutch comprises a drive housing (11), which rotates in a housing (20), a first shaft (21) which can be connected in a rotationally fixed manner to the drive housing, a second shaft (22) which is connected in a rotationally fixed manner to the drive housing, and furthermore a hydrostatic displacement machine (1), a friction clutch (12) for connecting the first shaft (21) to the drive housing (11), and a piston (10) for acting on the friction clutch (12), the drive housing (11) having a pressure space (9) and where a pressure is produced in the pressure space (9) when a difference in speed occurs in the pressure space (9), this pressure giving rise to action upon the friction clutch (12), and a passage (13) leading from the pressure space to a control valve which opens up the route to a space of lower pressure in a controlled manner.

Abstract: A viscous shear coupling for distributing torque between front and rear axles of an all-wheel drive vehicle is provided which comprises a housing, a set of inner blades interdigitating with a set of outer blades, the inner and outer blades being axially spaced apart from each other and axially slidably mounted within the housing, a viscous liquid located within the housing, an adjusting piston within the housing which is axially displaceable so as to adjust the axial distance between adjacent inner and outer blades. The viscous shear coupling further includes a control pressure circuit for delivery of a control pressure fluid to the adjusting piston, a control valve for regulating the delivery of the control pressure fluid to the adjusting piston, and a control device (e.g., a microprocessor) which calculates a desired adjusting piston speed based on driving conditions and adjusts a valve current delivered to the control valve in order to obtain the desired adjusting piston speed.