POWER TRANSMISSION MECHANISM, ACTUATOR, AND VEHICLE ACTUATOR

A torque limiter () includes a coil spring (), an inner shaft which is connected to a drive shaft () and is disposed to be inserted into a coil portion of the coil spring () so that the coil portion of the coil spring () is configured to come into close contact with an outer peripheral surface, a bottomed cylindrical outer member () which is disposed at the outside of the coil portion with a gap interposed therebetween and is provided relatively rotatable with respect to the inner shaft so that both end portions of a wire forming the coil spring () are locked thereto, and a drive gear () which is integrally formed with a plate portion () of the outer member () and is configured to transmit a rotational force to the screw shaft.