Rotary cooling fan for an AC generator

An alternating current generator for a vehicle comprising:

• a core comprising a pair of plates having plural claw shaped portions;
• a rotating shaft inserted into a center portion of said core;
• a rotor inserted and fixed to said rotating shaft and having an excitation current supply via a slip ring;
• a stator provided at an outer periphery of said rotor;
• and
• front and rear brackets arranged to surround said rotor and said stator;
• wherein
• said rotor is supported to rotate freely relative to each of said front and rear brackets through a bearing member;
• said core includes a front fan and a rear fan which are installed at opposite ends of said core;
• plural intake holes are provided to end portions of said respective front and rear brackets;
• plural exhaust holes are provided in an outer peripheral portion of said respective front and rear brackets;
• in accordance with a rotation of said rotor, an inner portion of said generator is ventilation-cooled using said front and rear fans;
• at least one of said front fan and said rear fan is a resin molding fan having an insert metal fitting;
• said resin molding fan is fixed to said core by joining said insert metal fitting to said core by using a joining means such as a welding;
• said resin molding fan is a centrifugal fan having a ring shaped supporting plate in which plural blades are provided projecting in an axial direction;
• and
• an inner diameter of said ring shaped supporting plate is substantially equal to an outer diameter of said rotating shaft of said rotor or an outer diameter of a resin portion of said slip ring which is inserted and fixed to said rotating shaft.