MANUFACTURE FRAME FOR MOTOR

摘要

The frame body producing method bends a flat plate into a round body which is then shaped into a true circle by being pressed in a radially inward direction by a metal mould. The edge surface portions opposing each other of the body to form a welded cylindrical frame body. Heat radiation fins are attached onto the outer circumferential surface of the frame body by welding. The frame body is deformed by the thermal stresses. The frame body is then plastically shaped into a true circle by pressing the inner circumferential surface in a radially outward direction until the frame body has a predetermined inner diameter.