The bearing provides an inner race, an outer race and a wear race that is made of synthetic material and fastened to one of the races. The wear race is overmolded on at least one face of the race. The face includes at least one retention means that is covered with the synthetic material of the wear race and shaped to allow both the axial retention and the angular retention of the wear race relative to the race by shape complementarity with the wear race.

A ball bearing and to a clutch thrust bearing device including such a bearing. The invention also relates to a driveline system including such a device, the system being provided to an all-wheel drive driveline system of a motor vehicle. The ball bearing comprises a fixed inner ring able to bear against an axially movable piston, a rotatable outer ring, and one series of balls between the rings. The rotatable outer ring further comprises a shield provided with a folded flange able to bear against a resilient biasing member.

A clutch actuation mechanism for actuating a clutch operator of a spring loaded friction clutch having at least a motor driven rotary disc for being connected to the clutch operator enables to operate the motor with an essentially constant and reduced torque, if a pin is attached to the disc with an offset from the disc's rotary axis, and if a lever has a curved contacting surface and if a spring forces the lever with its contacting surface against the pin to thereby provide an additional torque to the disc. Thus, the pin travels over the contacting surface when the disc rotates to open or close the spring loaded clutch via the clutch operator and the curvature enables to adapt the torque provided by the spring to the torque required to compensate for the clutch spring.

A ball bearing and to a clutch thrust bearing device including such a bearing. The invention also relates to a driveline system including such a device, the system being provided to an all-wheel drive driveline system of a motor vehicle. The ball bearing comprises a fixed inner ring able to bear against an axially movable piston, a rotatable outer ring, and one series of balls between the rings. The rotatable outer ring further comprises a shield provided with a folded flange able to bear against a resilient biasing member.

A clutch actuation mechanism for actuating a clutch operator of a spring loaded friction clutch having at least a motor driven rotary disc for being connected to the clutch operator enables to operate the motor with an essentially constant and reduced torque, if a pin is attached to the disc with an offset from the disc's rotary axis, and if a lever has a curved contacting surface and if a spring forces the lever with its contacting surface against the pin to thereby provide an additional torque to the disc. Thus, the pin travels over the contacting surface when the disc rotates to open or close the spring loaded clutch via the clutch operator and the curvature enables to adapt the torque provided by the spring to the torque required to compensate for the clutch spring.

A clutch rolling bearing centered on a central axis. The clutch rolling bearing includes a rotatable ring provided with a toroidal portion defining a first concave raceway and an engagement portion dedicated to cooperate with a diaphragm, a stationary ring mounted coaxially with the rotatable ring, provided with a toroidal portion defining a second concave raceway and dedicated to cooperate with a translating piston, and balls arranged between the first and second concave raceways of the rotatable and stationary rings. The engagement portion of rotatable ring extends from the toroidal portion on the diaphragm side, the engagement portion being folded against the toroidal portion on a surface radially opposite to the first raceway.

Release bearings for actuating a clutch are provided, and may include a bearing ring arranged non-rotatably on a sliding sleeve mounted on a transmission input shaft and a rotatable bearing ring, which interacts with a spring of the clutch. A row of rolling elements may be arranged radially between the two bearing rings and have pressure lines oriented obliquely with respect to a bearing longitudinal axis. The rolling elements may each be bodies of revolution with a circular-arc-shaped generatrix, wherein a center angle between radii bounding the circular-arc-shaped generatrix is smaller than 180. The non-rotatable bearing ring may have a raceway shaped complementary to a shape of the rolling elements and may guide the rolling elements in an axial direction. The rotatable bearing ring may have a raceway shaped as a spherical surface with a sphere radius corresponding to the generatrix of the rolling elements.

A structure of a powertrain for a vehicle according to the present invention includes: a first clutch connecting or disconnecting power from an engine; a driving motor disposed between the first clutch and a transmission, including a stator and a rotor, and having a recess, such that a center of a side of the rotor that faces the first clutch concaves toward the transmission; and an actuator at least partially inserted in the recess to operate the first clutch.

The invention relates to a clutch rolling bearing centered on a central axis and comprising a rotatable ring provided with a toroidal portion defining a first concave raceway and an engagement portion dedicated to cooperate with a diaphragm, a stationary ring mounted coaxially with the rotatable ring, provided with a toroidal portion defining a second concave raceway and dedicated to cooperate with a translating piston, and balls arranged between the raceways of the rings. The engagement portion of rotatable ring extends from the toroidal portion on the diaphragm side, the engagement portion being folded against the toroidal portion on a surface radially opposite to the first raceway.

A structure of a powertrain for a vehicle according to the present invention includes: a first clutch connecting or disconnecting power from an engine; a driving motor disposed between the first clutch and a transmission, including a stator and a rotor, and having a recess, such that a center of a side of the rotor that faces the first clutch concaves toward the transmission; and an actuator at least partially inserted in the recess to operate the first clutch.