A structure of a rotation locking device that is easily configured and capable of keeping cost down is achieved.

A rotation locking device 4 switches between a first mode where an engaging claw portion 14 engages with an engaging concave portion 9 by an output member 13 rotating an engaging member 8 due to an input member 12 being rotationally driven by an actuator 7, and rotation of a locking gear 5 supported by and fixed to an output shaft 3 of an automatic transmission 2 is restricted, and a second mode where engagement between the engaging claw portion 14 and the engaging concave portion 9 is released and rotation of the locking gear 5 is allowed.

A structure of a rotation locking device that is easily configured and capable of keeping cost down is achieved.

A rotation locking device 4 switches between a first mode where an engaging claw portion 14 engages with an engaging concave portion 9 by an output member 13 rotating an engaging member 8 due to an input member 12 being rotationally driven by an actuator 7, and rotation of a locking gear 5 supported by and fixed to an output shaft 3 of an automatic transmission 2 is restricted, and a second mode where engagement between the engaging claw portion 14 and the engaging concave portion 9 is released and rotation of the locking gear 5 is allowed.

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.

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).

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.

A rotation locking device 4 has a locking gear 5; a reverse input blocking clutch having an input member 12 and an output member 13; and an engaging member 8, and switches between a first mode where an engaging claw portion 14 engages with an engaging concave portion 9 by the output member 13 rotating the engaging member 8 due to the input member 12 being rotationally driven, and rotation of the locking gear 5 is restricted, and a second mode where engagement between the engaging claw portion 14 and the engaging concave portion 9 is released and rotation of the locking gear 5 is allowed.

A rotation locking device 4 has a locking gear 5; a reverse input blocking clutch having an input member 12 and an output member 13; and an engaging member 8, and switches between a first mode where an engaging claw portion 14 engages with an engaging concave portion 9 by the output member 13 rotating the engaging member 8 due to the input member 12 being rotationally driven, and rotation of the locking gear 5 is restricted, and a second mode where engagement between the engaging claw portion 14 and the engaging concave portion 9 is released and rotation of the locking gear 5 is allowed.

An electric assist device for a bicycle comprising a shaft coupled in rotation with a pair of cranks and being able to be rotated in a positive direction by an electric motor, a connection mechanism being placed between the motor and the shaft, which connection mechanism has at least three distinct states. The states includes State 1, termed assist state, in which the motor transmits a torque to the shaft via a drive part which rotates at the same speed as the shaft, State 2, termed freewheel state, in which the rotation of the shaft in the positive direction is greater than that of the drive part, and State 3, termed disconnection state, in which a rotation in the positive direction or in the negative direction of the shaft cannot cause the motor to rotate.