A driving force transmission mechanism includes a worm gear unit as a brake disposed between a driving motor and an electrically driven input gear, and is configured such that when a driving force is applied from the driving motor to the electrically driven input gear through the worm gear unit, an outer ring which rotates together with the electrically driven input gear becomes locked to an inner ring through rollers so that the driving force is transmitted to an output gear, which rotates together with the inner ring, and when a driving force is applied to a manually driven input shaft, the outer ring and the inner ring are unlocked from each other by an unlocking piece which rotates together with the manually driven input shaft, and thereafter, the driving force is transmitted to the inner ring and the output shaft.

A clutch unit includes an operation lever, an operation bracket, an output shaft member, an input-side clutch, an output-side clutch, and a housing. An input-side outer ring member of the input-side clutch is a member including a bottom part and an outer ring part. A part of the outer ring part is a thick part. The thickness of the thick part in the radial direction is larger than the thickness of a non-thick part in the radial direction.

A cam device having a drive cam and a driven cam; and a friction engagement device having at least one friction plate and at least one separation plate are provided. The friction engagement device is configured so as to be put into a connected state by pressing the friction plate and the separation plate against each other by the driven cam, and a disconnected state. Also provided are a rotation transmission state switching device having a first member and a second member coaxially arranged, and a mode selecting part configured to rotate or displace in the axial direction according to rotation of the drive cam. The rotation transmission state switching device has at least one mode of a free mode and a lock mode of the first member and the second member, and a one-way clutch mode.

A slip clutch assembly includes a clutch carrier, a one-way clutch assembly, and a preloaded clutch assembly. The one-way clutch assembly has a portion fixed to the clutch carrier. The preloaded clutch assembly has a first clutch plate, a second clutch plate, and a resilient element. The first clutch plate is drivingly engaged with the carrier. The second clutch plate is arranged for driving engagement with a first portion of a transmission. The resilient element is for compressing the first and second clutch plates. In some example embodiments, the one-way clutch assembly has an outer race, an inner race, and a plurality of blocking elements. The outer race is fixed to the clutch carrier. The inner race is arranged to engage a second portion of the transmission. The blocking elements are selected from the group of rollers or sprags for selectively locking the outer race to the inner race and are disposed radially between the outer race and inner race.

An object of the present invention is to provide a cam clutch capable of switching from one operating mode to another with a simple structure and with high responsiveness, and of securing an expected torque capacity. The cam clutch of the present invention includes an operating mode switch mechanism (140) for switching between a free state that allows relative rotation between an inner race (110) and an outer race (120) and a locked state that prohibits relative rotation between the inner race (110) and the outer race (120). The operating mode switch mechanism (140) includes a cam attitude change part (142) that is movable circumferentially, radially, or axially independently of the rotation of the inner race (110) and the outer race (120) to forcibly tilts a plurality of cams (131) circumferentially arranged between the inner race (110) and the outer race (120).

An object of the present invention is to provide a cam clutch capable of switching from one operating mode to another with a simple structure and with high responsiveness, and of securing an expected torque capacity. The cam clutch of the present invention includes an operating mode switch mechanism (140) for switching between a free state that allows relative rotation between an inner race (110) and an outer race (120) and a locked state that prohibits relative rotation between the inner race (110) and the outer race (120). The operating mode switch mechanism (140) includes a cam attitude change part (142) that is movable circumferentially, radially, or axially independently of the rotation of the inner race (110) and the outer race (120) to forcibly tilts a plurality of cams (131) circumferentially arranged between the inner race (110) and the outer race (120).

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).

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).

A variable compression ratio mechanism of an internal combustion engine includes an operation element, an input actuator, and a reverse input torque cutoff clutch. The reverse input torque cutoff clutch includes a fixed member, a movable member, clearance, a wedge member, and a moving device. A peripheral surface of the fixed member is formed such that the clearance is formed with: a rotation prevention area that prevents the movable member from rotating in a reverse input torque acting direction. When the movable member moves in the direction to change a mechanical compression ratio, the moving device moves the wedge member from the rotation prevention area to the rotation allowable area in an opposite direction and holds the wedge member in the rotation allowable area.

A joint structure includes a clutch unit interposed between a shaft joint and a shaft body which is one of an output shaft of a speed increaser and an input shaft of a power generator. The clutch unit includes: a shaft coupling portion rotating integrally with the shaft body; a joint coupling portion rotating integrally with the shaft joint; and a one-way clutch provided between the shaft coupling portion and the joint coupling portion. The one-way clutch makes a connection integrally rotatably between the shaft coupling portion and the joint coupling portion in a state in which a rotation speed of the output shaft is higher than that of the input shaft, and releases the connection between the shaft coupling portion and the joint coupling portion in a state in which the rotation speed of the output shaft is lower than that of the input shaft.