A transmission brake device includes: a friction plate set configured such that a plurality of rotation-side friction plates; an engaging piston disposed on an axial side of the friction plate set; a clearance adjustment piston disposed on a side of the engaging piston opposite to the friction plate set; a clearance adjustment hydraulic chamber configured to move the clearance adjustment piston; and an engaging hydraulic chamber configured to move the engaging piston; a biasing member disposed between each adjacent pair of the fixed-side friction plates, the biasing member being configured to bias each adjacent pair of the fixed-side friction plates in directions away from each other. The biasing member distributes the clutch clearance in a gap between each adjacent pair of the fixed-side friction plates when a hydraulic pressure is supplied only to the clearance adjustment hydraulic chamber.

A secondary drive unit (SDU) for the secondary axis of an all wheel drive vehicle consists of an SDU housing defining a first section for receiving a main shaft which is connected to a drive source and a second section for enclosing a twin clutch assembly. The twin clutch assembly has a common clutch housing connected to the main shaft, a left clutch for selectively connecting a left output shaft and the clutch housing, a right clutch for selectively connecting a right output shaft and the clutch housing, and a rigid center plate separating the left and right clutches. The twin clutch assembly may be activated by a dual action piston assembly to decrease all wheel drive synchronization and connection response times.

A secondary drive unit (SDU) for the secondary axis of an all wheel drive vehicle consists of an SDU housing defining a first section for receiving a main shaft which is connected to a drive source and a second section for enclosing a twin clutch assembly. The twin clutch assembly has a common clutch housing connected to the main shaft, a left clutch for selectively connecting a left output shaft and the clutch housing, a right clutch for selectively connecting a right output shaft and the clutch housing, and a rigid center plate separating the left and right clutches. The twin clutch assembly may be activated by a dual action piston assembly to decrease all wheel drive synchronization and connection response times.

A torque transmitting device for an automotive transmission includes a clutch housing with a plurality of internal splines, a clutch hub with a plurality of external splines extending radially outwardly from the clutch hub, a plurality of friction plates with internal teeth and a first and a second surface. The first and second surface having a friction material disposed thereon and at least one of the internal teeth has an aperture and the plurality of internal teeth intermesh with the plurality of external splines on the outer surface of the clutch hub, a plurality of reaction plates having a plurality of external teeth and a first and a second surface. The plurality of external teeth intermesh with the plurality of internal splines in the clutch housing, and a spacer member disposed in the aperture separates a first of the friction plates from a second of the friction plates.

A torque transmitting device for an automotive transmission includes a clutch housing with a plurality of internal splines, a clutch hub with a plurality of external splines extending radially outwardly from the clutch hub, a plurality of friction plates with internal teeth and a first and a second surface. The first and second surface having a friction material disposed thereon and at least one of the internal teeth has an aperture and the plurality of internal teeth intermesh with the plurality of external splines on the outer surface of the clutch hub, a plurality of reaction plates having a plurality of external teeth and a first and a second surface. The plurality of external teeth intermesh with the plurality of internal splines in the clutch housing, and a spacer member disposed in the aperture separates a first of the friction plates from a second of the friction plates.

A clutch for a lift fan comprises 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 width of an inner surface of the output shaft lug key varies along the axial length as a function of the proximity to a home axial position of each of the output clutch plates when in the disengaged position.

A clutch for a lift fan comprises 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 width of an inner surface of the output shaft lug key varies along the axial length as a function of the proximity to a home axial position of each of the output clutch plates when in the disengaged position.

A wet-type multi plate clutch having a obtaining hydraulic chamber, which is capable of increasing a fuel consumption efficiency by reducing a load of an oil pump for clutch oil for engaging the clutch and which realizes a simplified structure by eliminating a necessity of a canceller chamber.

A disk spring 46 is, at its outer peripheral part, is supported by a clutch drum 10 and contacts, at its inner peripheral part, with a spring presser part 12-1 of the piston 12. The disk spring 46 faces, at the side opposite the piston 12, with clutch pack 20. A forward movement of the piston 12 by operating pressure in a hydraulic chamber is transmitted to the clutch pack 20 via the disk spring 46, resulting in an engaged condition of the clutch pack 20. A driving force of the piston 12 by the hydraulic oil pressure is boosted under a lever ratio a/b of the disk spring 46 and is transmitted to the clutch pack 20. The disk spring 46 to the spring presser part 12-1 without obstructing the slide movement of the piston 12 of obtaining an increased radial length of the spring, resulting in an increased return force of the spring 46 for a positive reverse movement of the piston 12 for obtaining a disengaged condition of the clutch.

A balance module 10 for a clutch comprises a first annular piston part 11, a second annular piston part 12, which is arranged opposite the first piston part 11 in the axial direction and spaced therefrom, at least three spring elements 13 operating in the axial direction, which are arranged axially between the first 11 and the second piston part 12, and a sealing element 14 with at least one radially outwardly directed sealing lip 15, which is attached on the first piston part 11. The spring elements 13, the first 11 and the second piston part 12 are connected to one another in a loss-proof manner, in order to form an integral module 10.

A balance module 10 for a clutch comprises a first annular piston part 11, a second annular piston part 12, which is arranged opposite the first piston part 11 in the axial direction and spaced therefrom, at least three spring elements 13 operating in the axial direction, which are arranged axially between the first 11 and the second piston part 12, and a sealing element 14 with at least one radially outwardly directed sealing lip 15, which is attached on the first piston part 11. The spring elements 13, the first 11 and the second piston part 12 are connected to one another in a loss-proof manner, in order to form an integral module 10.