Method of making a cooling fan rotor for a rotating electrical machine in particular for an alternator for an automotive vehicle

摘要

A cooling fan rotor for a rotating electrical machine such as an alternator for an automotive vehicle, has n ventilating blades. The rotor is made by a method including the following steps:PP an elongated metal strip is formed;PPthe metal strip is formed with 2n surface portions comprising first surface portions and second surface portions, each of generally quadrilateral shape; and PPthe second quadrilateral surface portions are bent over on themselves successively or simultaneously, each about its median line, which is the line bisecting the angle defined by the sides of the said surface portion.