Vehicles that are relatively heavy and/or configured to transport heavy loads may utilize a powertrain comprising an electric machine capable of operating at high speeds and a multispeed transmission to propel the vehicle. An interface module is configured to modulate torque between the electric machine and the multispeed transmission allowing the electric machine to smoothly match speed as the multispeed transmission shifts between gears. The interface module facilitates efficient, predictable, and reliable modulation of torque between an input and an output of the powertrain of the vehicle.

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 spring assembly comprises an edge wound wave spring and a shim. The spring comprises a plurality of axially spaced, axially compressible wave-like turns extending between a first end portion and a second end portion. The first end portion comprises a plurality of closely arranged parallel turns. The shim comprises a shim body and at least one mounting lug projecting radially from the shim body. The mounting lug is received between adjacent turns of the first end portion of the edge wound wave spring for retaining the shim to the edge wound wave spring.

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.

In a power transmission apparatus, a centrifugal clutch includes a holder, a press, and springs to urge masses from a radially outer position to a radially inner position. The masses are each housed in an associated one of housing portions arranged in a circumferential direction of the holder such that the masses are radially movable. More than one spring is provided in the circumferential direction between an inner peripheral wall surface of each of the housing portions and an associated one of the masses to urge the associated mass from the radially outer position to the radially inner position.

A power transmission apparatus a centrifugal clutch including a holder and a press. The holder and the press are each circumferentially provided with protrusions fitted and attached to cut-outs of a clutch housing. The holder is an integrated assembly into which a mass that is being held is integrated. The integrated assembly and the press are non-connected separate components and are independently movable toward or away from each other.

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 torque limiter includes: a first rotary member configured to be rotated by a drive source; at least one first friction member engaged with the first rotary member; at least one second friction member arranged so as to overlap the first friction member, and configured to rotate with rotation of the first rotary member by using frictional force generated between the second friction member and the first friction member; and a second rotary member engaged with the second friction member. It is preferable that the first rotary member and the second rotary member be pivotally supported by an identical rotary shaft, and that, while either the first rotary member and the second rotary member is fixed to the rotary shaft, the other one be supported so as to be rotatable about the rotary shaft.

A clutch (100) having: a fixed hub (201), a movable hub (202), a plurality of discs (204). The fixed hub (201) and the movable hub (202) axially slide, getting farther or closer so as to transmit a variable axial load onto the discs (204). The clutch (100) has a pressure plate assembly (208) including a centrifugal assembly (210), having: a rotatable mass holder (211) and a plurality of mass elements (212) radially disposed. Each mass element (212) has a pivot (301) and is configured for a displacement (1002) by pivoting under centrifugal effects. The mass elements (212) are configured for bringing the movable hub (202) closer to the fixed hub (201), so as to increase the variable axial load and allowing the clutch (100) (automatic) engagement. Each mass element (212) has a main body (302) and a column element (303) which connects the pivot (301) with the main body (302).