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 driving force transmission apparatus includes: a pinion gear shaft having a pinion teeth portion, a first shaft portion extending from one side of the pinion teeth portion, and a second shaft portion extending from the other side of the pinion teeth portion; a ring gear meshing with the pinion teeth portion; a clutch housing capable of rotating relative to the pinion gear shaft on a rotation axis in coincidence with a rotation axis of the pinion gear shaft; a clutch mechanism located between the clutch housing and the first shaft portion of the pinion gear shaft; and a differential carrier accommodating the ring gear. The first shaft portion and the second shaft portion of the pinion gear shaft are supported by a first bearing and a second bearing, respectively. The clutch housing is supported by the pinion gear shaft through a third bearing fitted on the first shaft portion.

In order to provide a master cylinder, in particular for a clutch system, an actuating system or a braking system of a vehicle, which enables secure sealing of the cylinder chamber relative to the outside, as well as a reliable flow of hydraulic medium into the cylinder chamber, it is proposed that the piston comprises a first section which has a cylindrical lateral surface and a second section which has at least one region which is set back radially inwardly with respect to the cylindrical lateral surface of the first section, wherein at least one set-back region extends to an end of the piston and wherein the first and second sections are arranged on the piston in such a way that in an actuating position of the piston, the main sealing element in the first section of the piston abuts in sealing manner thereagainst and in the pressure equalization position of the piston, in the second section of the piston between the piston and the main sealing element, at least one gap is formed, through which hydraulic medium can flow along the piston from the supply chamber into the cylinder chamber in order to equalize the pressure.

A transmission includes a case, a clutch pack, a piston. The case defines a bore that transitions along a step from a first to a second diameter. The piston is disposed within the bore. The piston has first and second seals that engage the case along the first and second diameters, respectively. The piston defines a chamber that is encompassed by the piston, the case, the first seal, and the second seal. The piston is configured to engage a clutch pack when hydraulic fluid is channeled into the chamber.

A motor drive unit, in which an output end of a motor drive system using an electric motor as a power source and a rotator rotatably supported by a bearing unit are arranged side by side in an axial direction, and the output end of the motor drive system and the rotator are drivingly coupled in a relatively displaceable manner by a coupling member in which a plurality of couplers spaced apart in an axial direction are set. The bearing unit of the rotator is arranged such that a center of displacement of the rotator defined by the bearing unit is located between an arbitrary pair of couplers among the couplers.

A coupling assembly having a first member drivingly connected to a second member via one or more third members. A first shaft is drivingly connected to the first member and a second shaft is drivingly connected to the second member. The second member includes a flange portion having one or more seating portions on a first end portion of the flange. Additionally, the flange has one or more flange portion attachment apertures extending from the seating portions to a second end portion of the flange. An increased diameter portion of the second shaft has one or more increased diameter portion apertures extending from a first end portion to a second end portion. The flange portion apertures and the increased diameter portion apertures have a center-line with an angle from an axial center-line of the assembly. Additionally, the seating portions have an angle relative to a radial center-line of the assembly.

Apparatus, such as a propeller shaft, includes an outer circumferential portion or outer race to rotate as a unit with an internal shaft (serving as the propeller shaft), an inner circumferential member or inner race to rotate as a unit with an external shaft and a plurality of balls disposed between the outer race and inner race, for transmitting rotation therebetween. A sleeve rotating as a unit with the inner race includes an inside cavity for receiving the external shaft. The sleeve is coated with a coating formed on an inside circumferential surface.

The clutch piston assembly includes a one piece piston body which extends about an axis and has at least one radially inwardly facing surface and at least one radially outwardly facing surface. At least one seal is engaged with the piston body and extends either radially outwardly from the radially outwardly facing surface or radially inwardly from the radially inwardly facing surface. The seal is made of polyetheretherketone (PEEK) or polyaryletherketone (PAEK) for establishing a low friction and fluid tight seal between the piston body and a wall in the automatic transmission.

Power transmission systems including clutch arrangements and systems are adapted to be used in marine and other environments. Such power transmission systems may include clutch arrangements that provide more effective power transmission capabilities as well as greater durability and longer life. Slipping clutch arrangements may effectively vary the output speed of a clutch arrangement from the speed of the engine or other driver as desired for the particular application. Various clutch arrangements also provide for greater flexibility and drive options, lighter weight, and diverse types of capabilities.

A hybrid drivetrain having an internal combustion engine which is designed for a maximum internal combustion engine rotational speed; a dual-clutch arrangement which has a first friction clutch and a second friction clutch with a common input element and in each case one output element; a transmission arrangement which has a first sub-transmission and a second sub-transmission; an electric machine connected to the output element of the second friction clutch via a machine transmission ratio (i.sub.M), in such a way that a purely electric driving mode can be established via the second sub-transmission. The electric machine is designed for a maximum machine rotational speed. The maximum machine rotational speed divided by the machine transmission ratio is greater than the maximum internal combustion engine rotational speed. The output element of the second friction clutch is structurally designed for the maximum machine rotational speed divided by the machine transmission ratio (i.sub.M).