A clutch has an inner race, an outer race spaced from the inner race and forming a radial cavity between the races, and a plurality of sprags disposed in the radial cavity. The sprags have a different coefficient of thermal expansion (CTE) from the inner race, the outer race, or both races, and a sprag cage retains the sprags at a uniform spacing within the radial cavity. When the clutch is at a first temperature, a gap exists between the sprags and the inner race, between the sprags and the outer race, or between the sprags and both races, and the clutch is disengaged. When the clutch is at a second temperature the sprags are in contact with both the races, and the clutch is engaged.

The present invention aims at providing a cam clutch that prevents cams from unwanted wedging and enables smooth operation including the switching between operation modes without involving an increase in size or number of components and with a simple structure. The cam clutch according to the present invention uses first cams and second cams having different engaging directions as sprags for transmitting and interrupting torque between an inner race and an outer race. A cam interlock mechanism tilts the second cams to a disengaging direction with a tilting motion of the first cams toward an engaging direction, to separate engaging surfaces of the second cams from raceways of the inner race and/or the outer race.

To provide a simple-structured cam clutch that does not require precise control, uses a smaller drive force for forcibly changing cam postures, and provides improved clutch operation stability and high responsiveness. The cam clutch includes a plurality of cams circumferentially arranged between an inner race and an outer race and supported by a cage member, and a selector allowing a rotation angle thereof to be controlled relatively to the inner race or the outer race to which the cage member is fixed. The selector has a cam posture control surface in contact with cam surfaces of the cams and capable of causing the cams to change posture thereof. The cam posture control surface includes a cam release portion radially protruded toward the cams more than a cam actuator portion and causing the cams to change posture thereof to a non-operating posture.

A drive system includes an inner race member and an outer race member. A first disengageable sprag clutch is disposed between the inner race member and the outer race member, the first disengageable sprag clutch having a drive direction and a freewheeling direction. A second disengageable sprag clutch is disposed between the inner race member and the outer race member, the second disengageable sprag clutch having a drive direction and a freewheeling direction that are opposite the drive direction and the freewheeling direction of the first disengageable sprag clutch.

A drive system includes an inner race member and an outer race member. A first disengageable sprag clutch is disposed between the inner race member and the outer race member, the first disengageable sprag clutch having a drive direction and a freewheeling direction. A second disengageable sprag clutch is disposed between the inner race member and the outer race member, the second disengageable sprag clutch having a drive direction and a freewheeling direction that are opposite the drive direction and the freewheeling direction of the first disengageable sprag clutch.

An object of the present invention is to provide a cam clutch capable of switching from one operating mode to another and offering improved stability of clutch operations and high responsiveness. The object is achieved by an operating mode switching means (180) having a cam attitude change part (185) being drivable independently of rotation of the inner race (110) and outer race (120). A load support point (Sp) is located radially between a load application point (Ap) of the cam attitude change part (185) on the cam (140) and a distal contact point (Ep) of the cam (140) on a raceway positioned on a radially distal side relative to the load application point (Ap). The radial distance (d1) between the load application point (Ap) and the load support point (Sp) is larger than the radial distance (d2) between the load support point (Sp) and the distal contact point (Ep).

To provide a simple-structured cam clutch that does not require precise control and is operable with a smaller drive force and less prone to damage on cam surfaces or inner and outer raceways. The cam clutch includes a plurality of cams circumferentially arranged between an inner race and an outer race and supported by a cage member, and a selector capable of changing an orientation of the cams. The selector includes a driven part allowing a rotation angle thereof to be controlled relative to the inner race or outer race to which the cage member is fixedly attached, and a selector body circumferentially displaceable relative to the driven part in a resilient manner by a spring-loaded mechanism. The selector body includes a cam orientation control protrusion capable of changing the orientation of the cams by making contact with the cams.

A reverse-input blocking clutch includes: a pressed member having a pressed surface; an input member having an input-side engaging portion on an inner side in a radial direction of the pressed surface; an output member having an output-side engaging portion further on the inner side in the radial direction than the input-side engaging portion; an engaging element on the inner side in the radial direction of the pressed surface to move in a first direction away from or toward the pressed surface, having a main engaging element body having a pivot-support shaft, and a link member having a first end portion pivotally linked to the pivot-support shaft and a second end portion pivotally linked to the input-side engaging portion; and an elastic body between the main engaging element body and the link member and applying an elastic force to the link member toward the pressed surface in the first direction.

A permanently engaged starter system for use in a vehicle, with the vehicle including a crankshaft and an engine block, includes a dual-mass flywheel and a permanently engaged starter assembly. The dual-mass flywheel extends along an axis and has an inner diameter portion disposed about and adjacent the axis and an outer diameter portion disposed about the axis such that the inner diameter portion is disposed between the outer diameter portion and the axis. The permanently engaged starter assembly includes a one-way clutch and a ring gear. The one-way clutch extends along the axis and includes an inner member disposed about the axis and an outer member disposed about the inner member. The ring gear is rotatably coupled to the one-way clutch and is adapted to be rotatably coupled to the outer diameter portion of the dual-mass flywheel through the one-way clutch.

A two-mode rocker clutch, including: a clutch gear; a housing; a first pawl including an end and a portion disposed within the housing; an actuation assembly; a second pawl including a portion disposed within the housing; and a resilient element urging the second pawl into contact with the clutch gear. For a one-way mode, the clutch gear is rotatable, with respect to the housing, only in a first circumferential direction. To transition from the one-way mode to a locked mode: the second pawl blocks rotation of the clutch gear, with respect to the housing, in a second circumferential direction, opposite the first circumferential direction; the actuation assembly is arranged to pivot the first pawl into contact with the clutch gear; and the end of the first pawl is arranged to block rotation of the clutch gear, with respect to the housing, in the first circumferential direction.