Motor apparatus

An input disk (62) and a clutch disk (78) are supported by an output shaft (18) in such a manner that the input disk (62) is rotatable relative to the output shaft (18), and the clutch disk (78) is non-rotatable relative to and is axially movable relative to the output shaft (18). When a large load torque is exerted about the output shaft (18), relative rotation between the input disk (62) and the clutch disk (78) occurs. A connecting rod (40) has one end connected to a worm wheel (36), and is reciprocally swung through rotation of the worm wheel (36). A rotatable lever (88) has one end, which is connected to the other end of the connecting rod (40), and has the other end, which is engaged with and is secured integrally with the gear teeth (68) of the input disk (62).