Abstract: A pulse vacuum hub lock system for selectively engaging a wheel hub to an axial shaft includes a cartridge housing assembly received in a bore in the wheel hub. The cartridge housing assembly supports a clutch ring for movable engagement between splines in the wheel hub and directly on the axle shaft. A diaphragm is connected to a piston assembly and is responsive to a vacuum pressure to activate the piston assembly to engage or disengage a latch mechanism that holds the clutch ring in an engaged or disengaged position. A piston spring and a helper spring are provided between primary and secondary pistons of the piston assembly and allow for separation in the vacuum levels required to activate the latch mechanism. The vacuum hub lock system is compact so as to be disposed inboard of an opening in the exterior surface of a wheel rim.

Abstract: A clutch actuator controlled by a pressure medium, in particular for a compressor clutch of a commercial vehicle has an actuating piston displaceably disposed in a housing in an axial direction. An end of the actuating piston is supported in the axial direction on an elastic membrane, sealing a first region of the housing off from a second region of the housing. The elastic membrane includes a raised area on the side opposite the actuating piston. The clutch actuator can be used in a compressor clutch for a commercial vehicle.

Abstract: A friction clutch or brake having an axially movable pressure piston arrangement and at least one annular shoulder, to which pressure can be applied by the pressure piston arrangement. The pressure piston arrangement has at least two pistons, which can be applied to the at least one annular shoulder in succession and in stages in a pressure-dependent manner.

Abstract: Taught herein is a clutch control apparatus that suppresses oil leakage from a seal member of a hydraulic cylinder even when vibration occurs, without enhancing sealability of the seal member per se. The clutch control apparatus includes normally-closed first clutch, a hydraulic cylinder, a piston, a lip seal and a pressure holding control section. The first clutch is disposed between an engine and driving wheels and is held in engagement by an elastic force applied to the first clutch CL1 by a diaphragm spring. The lip seal is disposed on the piston and enhances sealability between the piston and a housing slide surface in accordance with an increase in hydraulic pressure in the piston chamber. When the first clutch is engaged, the pressure holding control section applies a hydraulic pressure to retain the sealability of the lip seal to the piston chamber while maintaining engagement of the first clutch.

Abstract: A clutch assembly with a first drum clutch and a second drum clutch supported by an adapter hub and arranged so that the second clutch is disposed concentrically inside the first clutch. Each drum clutch has an inflatable tube and a plurality of friction shoes disposed on the inflatable tube. Arranging two drum clutches concentrically increases the torque capacity of the clutch assembly without increasing its footprint.

Abstract: A clutch actuator controlled by a pressure medium, in particular for a compressor clutch of a commercial vehicle has an actuating piston displaceably disposed in a housing in an axial direction. An end of the actuating piston is supported in the axial direction on an elastic membrane, sealing a first region of the housing off from a second region of the housing. The elastic membrane includes a raised area on the side opposite the actuating piston. The clutch actuator can be used in a compressor clutch for a commercial vehicle.