Clutch, motor and vehicle door opening/closing device

A clutch for provision between a drive shaft and a driven shaft to operate to couple the drive shaft to the driven shaft when a drive force is transmitted from the drive shaft and uncouple the driven shaft from the drive shaft during non-driving of the drive shaft, the clutch comprising:

• a driving-side rotating body capable of rotating integrally with the drive shaft;
• a driven-side rotating body capable of rotating integrally with the driven shaft;
• a holding case capable of rotating relative to the driving-side rotating body;
• a power transmitting member that is held by one of the driving-side rotating body and the holding case so as to be rotatable integrally with the one of the driving-side rotating body and the holding case, the power transmitting member being arranged between the driving-side rotating body and the driven-side rotating body in the radial direction and being moved between a non-engaging position, where the driving-side rotating body does not engage with the driven-side rotating body in a rotational direction, and an engaging position located radially outward from the non-engaging position, where the driving-side rotating body engages with the driven-side rotating body in the rotational direction;
• and
• a guiding member having a cam portion that is engaged with the power transmitting member and guides movement of the power transmitting member between the engaging position and the non-engaging position, the guiding member being held by the other of the driving-side rotating body and the holding case so as to be rotatable integrally with the other of the driving-side rotating body and the holding case, wherein
• at start of rotational driving of the driving-side rotating body, relative rotation between the driving-side rotating body and the holding case occurs, resulting in that the power transmitting member is guided by the cam portion to move from the non-engaging position to the engaging position.