METHOD AND STRUCTURE FOR PREVENTING SCREW FROM LOOSENING AND METHOD OF MANUFACTURING MALE SCREW

摘要

A method for preventing a screw from loosening, wherein before a male screw (18A) formed in the outer periphery of a second member (18) is threaded into a male screw (15A) formed in the inner periphery of the hole (15) of a first member (5), a swelled part (40) swelled to the radial outer side and positioned at the axial one end of the male screw (18A) is formed on the outer periphery of the second member (18) in which the male screw (18A) is formed at a plurality of positions apart from each other in the circumferential direction. Then, the male screw (18A) is threaded into the female screw (15A) from the axial other end of the male screw (18A). A torque required for rotating the male screw (18A) threaded with the female screw (15A) in a loosening direction in such a state that the swelled part (40) is interposed between the male screw (18A) and the female screw (15A) is set larger than that in such a state that the swelled part is not interposed between the male screw and the female screw.