A friction clutch with a clutch plate having a hub member, a rim portion and a plurality of rib members. The hub member has a plurality of female hub teeth. The rim portion is disposed concentrically about the hub member and has a rim member and a friction material that is coupled to the rim member. Each of the rib members extend radially between the hub member and the rim member to couple the hub member and the rim member to one another. Each one of the rib members is intersected by at least three of the other rib members. Each of the other rib members intersecting the one of the rib members at a distinct location such that the distinct locations are spaced apart from one another along the one of the rib members.

A power transmission device has an interlocking member 9 moving a pressure member 5 from an inactive position to an active position. A release spring (m) applies an urging force, while allowing movements of the interlocking member 9 and the pressure member 5, until drive-side clutch plates 6 and driven-side clutch plates 7 reach an engaged state before the drive-side clutch plates 6 and the driven-side clutch plates 7 are pressed against each other. A clutch spring 11 is compressed in a process where the interlocking member 9 moves after the drive-side clutch plates 6 and the driven-side clutch plates 7 have reached the engaged state. The clutch spring applying a press-contact force between the drive-side clutch plates 6 and the driven-side clutch plates 7 while allowing movements of the interlocking member 9 and the pressure member 5. The set load of the clutch spring 11 is set to be smaller than the maximum load of the release spring (m).

A control device controls a torque transmission device. The torque transmission device includes an actuator that operates by being energized and a torque transmission portion that is switched to a transmission state or a non-transmission state by the actuator operating, and transmits a torque between a first transmission portion and a second transmission portion when the torque transmission portion is in the transmission state. The control device includes a target calculation unit, a mode determination unit, and a control unit. The target calculation unit calculates a target transmission torque that is a torque to be transmitted between the first transmission portion and the second transmission portion. The mode determination unit determines an operating mode among an engagement mode, a release mode, and a steady mode. The control unit controls the actuator based on the operating mode determined by the mode determination unit.

A clutch having: a fixed hub, a movable hub, and a plurality of plates interposed to selectively transmit a torque. The clutch has a centrifugal pressure plate assembly having: a mass carrier; a plurality of radially movable mass elements, in which each mass element has a pivot connected to the mass carrier for displacement towards an external position under centrifugal effects; wherein the mass elements are further configured to exert axial thrust on a thrust surface of the centrifugal pressure plate assembly, to bring the movable hub closer to the fixed hub and increase the variable axial load. Each mass element has at least one respective rolling element in contact with the thrust surface. The thrust surface has a profile that is sloped and raised towards the external position.

A clutch having: a fixed hub, a movable hub, and a plurality of plates interposed to selectively transmit a torque. The clutch has a centrifugal pressure plate assembly having: a mass carrier; a plurality of radially movable mass elements, in which each mass element has a pivot connected to the mass carrier for displacement towards an external position under centrifugal effects; wherein the mass elements are further configured to exert axial thrust on a thrust surface of the centrifugal pressure plate assembly, to bring the movable hub closer to the fixed hub and increase the variable axial load. Each mass element has at least one respective rolling element in contact with the thrust surface. The thrust surface has a profile that is sloped and raised towards the external position.

During movement of a mass of a centrifugal clutch a radially inner position to a radially outer position and a resulting increase in torque transmitted from an input gear to an output shaft, a power transmission apparatus includes a first torque region where the apparatus restricts operation of a pressing assist cam and a second torque region where the apparatus allows operation of the pressing assist cam.

A control device controls a torque transmission device. The torque transmission device includes an actuator that operates by being energized and a torque transmission portion that is switched to a transmission state or a non-transmission state by the actuator operating, and transmits a torque between a first transmission portion and a second transmission portion when the torque transmission portion is in the transmission state. The control device includes a target calculation unit, a mode determination unit, and a control unit. The target calculation unit calculates a target transmission torque that is a torque to be transmitted between the first transmission portion and the second transmission portion. The mode determination unit determines an operating mode among an engagement mode, a release mode, and a steady mode. The control unit controls the actuator based on the operating mode determined by the mode determination unit.

Provided are a wet friction plate and a wet multiplate clutch device including the wet friction plates capable of improving the performance for discharging lubricant oil adhering to surfaces of friction members. A wet friction plate includes oil grooves and friction members on a flat plate annular core metal. At a surface of a porous layer of the friction member, a friction slide surface and lubricant oil recessed portions are formed. The lubricant oil recessed portion has no sharp portion in a pointed shape, such as a corner portion, and is formed with a smooth continuous surface. The multiple lubricant oil recessed portions depressed in a recessed shape with respect to the friction slide surface are formed. In the porous layer, hollow portions are formed to have the same formation rate between a portion forming the friction slide surface and a portion forming the lubricant oil recessed portion.

Provided are a wet friction plate and a wet multiplate clutch device including the wet friction plates capable of improving the performance for discharging lubricant oil adhering to surfaces of friction members. A wet friction plate includes oil grooves and friction members on a flat plate annular core metal. At a surface of a porous layer of the friction member, a friction slide surface and lubricant oil recessed portions are formed. The lubricant oil recessed portion has no sharp portion in a pointed shape, such as a corner portion, and is formed with a smooth continuous surface. The multiple lubricant oil recessed portions depressed in a recessed shape with respect to the friction slide surface are formed. In the porous layer, hollow portions are formed to have the same formation rate between a portion forming the friction slide surface and a portion forming the lubricant oil recessed portion.

A continuously variable transmission (“CVT”) is provided for use on a recreational or utility vehicle. The CVT is electronically controlled by a control unit of the vehicle. The CVT includes a primary clutch having a first sheave, a second sheave movable relative to the first sheave, and a friction clutch. An actuator assembly is configured to actuate the primary clutch and cause movement of the second sheave.