A stator fastening structure of a reciprocating motor is provided. 05 to about 5 weight percent of an organo molybdenum compound; and about 0. The second changeover portion makes a changeover from the manual shift mode to the automatic shift mode on the basis of a relationship between the first driving force related value and the second driving force related value. In response to the feedback signal and an operating-status signal issued by the system circuit, the first and second switching circuits are alternately enabled under control of the control circuit such that electric energy of a first DC voltage is transmitted from the first primary winding assembly to the secondary winding assembly.