A brake-side clutch part includes an outer ring whose rotation is restricted and an output shaft from which rotation is output. The outer ring is provided with a slide gear that meshes with the output shaft when rotational torque is cut off and releases a meshing state with the output shaft when rotational torque is transmitted. The output shaft is provided with an inner gear that meshes with the slide gear so as to be slightly rotatable. An alignment part that aligns a phase of the inner gear with that of the slide gear when rotational torque is cut off, and a centering part that returns the inner gear to a neutral position with respect to the output shaft when rotational torque is transmitted are provided between the inner gear and the output shaft.

A phasing system is provided. A phase angle between the gear hub and the cradle rotor can be driven by a planetary actuator. In some non-limiting examples, an input shaft rotationally coupled between a rotary actuator for rotation therewith. Rotation of the input shaft can unlock relative rotation between the cradle rotor and the gear hub. In some non-limiting examples, the phasing system can include a gear hub and a cradle rotor, and a torsion spring arrange therebetween. The torsion spring can be configured to apply an internal torque load between the gear hub and the cradle rotor to offset an external torque load applied to the gear hub or the cradle rotor.

A damper device includes a first rotor, a second rotor, an elastic coupling part having first and second elastic members, and a hysteresis generating mechanism. The hysteresis generating mechanism includes a friction member, and generates a hysteresis torque. The friction member does not make frictional contact with the first and second rotors in a first torsion angular range where the torsion is caused between the first and second rotors by a first torsion angle from a neutral condition, makes frictional contact with the first or second rotor in a second torsion angular range exceeding the first torsion angle so as to generate the hysteresis torque, and does not make frictional contact with the first and second rotors in a predetermined torsion angular range within the second torsion angular range. In the neutral condition, the friction member is set in a neutral position by actuation of the elastic coupling part.

A phasing system is provided. A phase angle between the gear hub and the cradle rotor can be driven by a planetary actuator. In some non-limiting examples, an input shaft rotationally coupled between a rotary actuator for rotation therewith. Rotation of the input shaft can unlock relative rotation between the cradle rotor and the gear hub. In some non-limiting examples, the phasing system can include a gear hub and a cradle rotor, and a torsion spring arrange therebetween. The torsion spring can be configured to apply an internal torque load between the gear hub and the cradle rotor to offset an external torque load applied to the gear hub or the cradle rotor.

A brake-side clutch part includes an outer ring whose rotation is restricted and an output shaft from which rotation is output. The outer ring is provided with a slide gear that meshes with the output shaft when rotational torque is cut off and releases a meshing state with the output shaft when rotational torque is transmitted. The output shaft is provided with an inner gear that meshes with the slide gear so as to be slightly rotatable. An alignment part that aligns a phase of the inner gear with that of the slide gear when rotational torque is cut off, and a centering part that returns the inner gear to a neutral position with respect to the output shaft when rotational torque is transmitted are provided between the inner gear and the output shaft.

A rotary device includes a rotatable member and a limiting member. The rotatable member includes a positioning mechanism, the positioning mechanism includes a stopping member and a positioning member. When the rotatable member rotates along a first rotation direction to make the limiting member abut against the positioning member, the positioning member is pushed by the limiting member to move away from the stopping portion and rotate relative to the stopping member, so that the positioning member to passes through the limiting member. When the rotatable member rotates along a second rotation direction opposite to the first rotation direction to make the limiting member abut against the positioning member, the positioning member is pushed by the limiting member to move close to the stopping portion, so that the positioning member is stopped between the limiting member and the stopping portion, to position the rotatable member.

A rotary device includes a rotatable member and a limiting member. The rotatable member includes a positioning mechanism, the positioning mechanism includes a stopping member and a positioning member. When the rotatable member rotates along a first rotation direction to make the limiting member abut against the positioning member, the positioning member is pushed by the limiting member to move away from the stopping portion and rotate relative to the stopping member, so that the positioning member to passes through the limiting member. When the rotatable member rotates along a second rotation direction opposite to the first rotation direction to make the limiting member abut against the positioning member, the positioning member is pushed by the limiting member to move close to the stopping portion, so that the positioning member is stopped between the limiting member and the stopping portion, to position the rotatable member.

The reverse input shutoff clutch includes: an input member, an output member coaxially arranged with the input member, a pressed member having a pressed surface, and an engaging element. The engaging element, when rotational torque is inputted to the input member, moves in a direction away from the pressed surface due to engagement with the input member and transmits the rotational torque to the output member, and when rotational torque is reversely inputted to the output member, moves in a direction toward the pressed surface due to engagement with the output member, and prevents or suppresses relative rotation between the output member and the pressed member.

The reverse input shutoff clutch includes: an input member, an output member coaxially arranged with the input member, a pressed member having a pressed surface, and an engaging element. The engaging element, when rotational torque is inputted to the input member, moves in a direction away from the pressed surface due to engagement with the input member and transmits the rotational torque to the output member, and when rotational torque is reversely inputted to the output member, moves in a direction toward the pressed surface due to engagement with the output member, and prevents or suppresses relative rotation between the output member and the pressed member.

Torque of a prime mover is input into a sun gear. A planetary gear revolves in a circumferential direction of the sun gear while rotating and meshing with the sun gear. A carrier has an annular shape, rotatably supports the planetary gear, and is rotatable relative to the sun gear. A first ring gear is fixed to a housing, and meshes with the planetary gear. A second ring gear meshes with the planetary gear, is different from the first ring gear in number of teeth of a tooth portion, and outputs torque to a rotation portion. At least a part of the sun gear in an axial direction is located radially inward of the carrier. At least a part of the first ring gear and at least a part of the second ring gear in the axial direction are located radially outward of the carrier.