A clutch arrangement is formed with drive-side and, output-side clutch elements and a clutch piston for operative connection and disengagement between the drive-side and output-side clutch elements. Associated with at least two clutch elements is an elastically deformable clutch element working mechanism through which the corresponding clutch elements can be acted upon in direction away from one another by an axial force to assist disengagement of the drive-side and output-side clutch elements. The clutch element working mechanism provides a considerable change in the gradient of the axial force exerted on the clutch elements as a result of even a small change of shape of the clutch element working mechanism so that a sharply rising axial force of the clutch element working mechanism works against the clutch piston.

A friction clutch having at least one clutch part (1; 31) which has at least one friction lining (3; 33) with a friction surface (10; 40) which, when the friction clutch is closed, is connected in frictionally engaging fashion to a counterpart clutch part, wherein the friction lining (3; 33) and/or a carrier element (6) of the friction lining (3; 33) is, in a circumferential direction, of undulating shape with wave troughs (20) and wave crests (18, 19), wherein, when the friction clutch is open, the friction lining (3; 33) comes into contact with the counterpart clutch part not with the entire friction surface (10; 40) but only substantially in punctiform fashion in the area of peaks (15-17) of the wave crests (18, 19). The friction lining (3; 33) has reduced friction values locally in the region of the peaks (15-17) of the wave crests (18, 19) in relation to the friction surface (10; 40) surrounding the peaks (15-17) of the wave crests (18, 19).

A friction clutch having at least one clutch part (1; 31) which has at least one friction lining (3; 33) with a friction surface (10; 40) which, when the friction clutch is closed, is connected in frictionally engaging fashion to a counterpart clutch part, wherein the friction lining (3; 33) and/or a carrier element (6) of the friction lining (3; 33) is, in a circumferential direction, of undulating shape with wave troughs (20) and wave crests (18, 19), wherein, when the friction clutch is open, the friction lining (3; 33) comes into contact with the counterpart clutch part not with the entire friction surface (10; 40) but only substantially in punctiform fashion in the area of peaks (15-17) of the wave crests (18, 19). The friction lining (3; 33) has reduced friction values locally in the region of the peaks (15-17) of the wave crests (18, 19) in relation to the friction surface (10; 40) surrounding the peaks (15-17) of the wave crests (18, 19).

A clutch for a lift fan comprising at least one output shaft lug key positioned in a keyway of at least two output clutch plates and extending axially from one to the other of the two output clutch plates. The output shaft lug key couples the rotation of the output clutch plates to the rotation an output shaft and allows axial movement of the two output clutch plates relative the output shaft lug key. The output shaft has an outer radial surface and an oppositely disposed inner radial surface, and the inner surface of the output shaft lug key extends radially to the seat of the keyway.

A clutch for a lift fan comprising at least one output shaft lug key positioned in a keyway of at least two output clutch plates and extending axially from one to the other of the two output clutch plates. The output shaft lug key couples the rotation of the output clutch plates to the rotation an output shaft and allows axial movement of the two output clutch plates relative the output shaft lug key. The output shaft has an outer radial surface and an oppositely disposed inner radial surface, and the inner surface of the output shaft lug key extends radially to the seat of the keyway.

A twin plate separation system, comprising a pressure plate, an intermediate plate facing the pressure plate, and a spring separator assembly. The spring separator assembly comprises a mounting extending out from the intermediate plate towards the pressure plate. A spring surrounds the mounting, and the spring is biased to push the pressure plate and the intermediate plate apart. The mounting or another fixture can secure at least one drive strap to the intermediate plate. Alternatively, the mounting extends out of the pressure plate towards the intermediate plate, and the spring surrounds the mounting and is biased to push the pressure plate and the intermediate plate apart. In this alternative, the intermediate plate does not comprise a hole for receiving the mounting.

A twin plate separation system, comprising a pressure plate, an intermediate plate facing the pressure plate, and a spring separator assembly. The spring separator assembly comprises a mounting extending out from the intermediate plate towards the pressure plate. A spring surrounds the mounting, and the spring is biased to push the pressure plate and the intermediate plate apart. The mounting or another fixture can secure at least one drive strap to the intermediate plate. Alternatively, the mounting extends out of the pressure plate towards the intermediate plate, and the spring surrounds the mounting and is biased to push the pressure plate and the intermediate plate apart. In this alternative, the intermediate plate does not comprise a hole for receiving the mounting.

A transmission includes a case defining a bore and a piston disposed within the bore. The piston and the case define a fluid chamber in fluid communication with a fluid source. The piston includes an annular piston body defining a plurality of auxiliary bores angularly spaced along the annular piston body about a central axis of the annular piston body. The piston further includes a plurality of auxiliary pistons disposed within the auxiliary bores. The piston body and the auxiliary pistons have rear surfaces in communication with the fluid chamber. The transmission further includes a clutch pack disposed opposite the piston from the fluid chamber. The clutch pack includes at least one friction plate, at least one separator plate, and at least one separator spring. The transmission further includes a return spring adapted to bias the annular piston body in a direction away from the clutch pack.

A twin plate separation system, comprising a pressure plate, an intermediate plate facing the pressure plate, and a spring separator assembly. The spring separator assembly comprises a mounting extending out from the intermediate plate towards the pressure plate. A spring surrounds the mounting, and the spring is biased to push the pressure plate and the intermediate plate apart. The mounting or another fixture can secure at least one drive strap to the intermediate plate. Alternatively, the mounting extends out of the pressure plate towards the intermediate plate, and the spring surrounds the mounting and is biased to push the pressure plate and the intermediate plate apart. In this alternative, the intermediate plate does not comprise a hole for receiving the mounting.

A twin plate separation system, comprising a pressure plate, an intermediate plate facing the pressure plate, and a spring separator assembly. The spring separator assembly comprises a mounting extending out from the intermediate plate towards the pressure plate. A spring surrounds the mounting, and the spring is biased to push the pressure plate and the intermediate plate apart. The mounting or another fixture can secure at least one drive strap to the intermediate plate. Alternatively, the mounting extends out of the pressure plate towards the intermediate plate, and the spring surrounds the mounting and is biased to push the pressure plate and the intermediate plate apart. In this alternative, the intermediate plate does not comprise a hole for receiving the mounting.