POWER TRANSMISSION DEVICE

A transmission device for interruptibly transmitting torque between a first rotary member and a second rotary member respectively rotatable about an axis is comprised of a clutch disconnectably and drivingly coupling the first rotary member with the second rotary member; a motor including a rotor rotatable about the axis; an input member coupled with the rotor and rotatable about the axis, the input member including an eccentric shaft eccentric relative to the axis; a fixed member immovable about the axis; an intermediate member fitting with the eccentric shaft to make an eccentric motion and meshing with the fixed member to make a rotary motion about the eccentric shaft; an output member rotatable about the axis and fitting with and following the intermediate member; and a cam mechanism intervening between the output member and the clutch to convert a rotary motion of the output member into a motion in a direction along the axis to press the clutch.