Patent ID: 8429810

Claim:
A method of manufacturing a rotor for a dynamoelectric machine, the rotor including a rotor core supported by a rotating shaft and at least one cooling fan fixed to an axial end face of the rotor core, the method comprising a step of resistance-welding the cooling fan to the axial end face of the rotor core, wherein the cooling fan includes a plurality of fan blades and a ring portion located radially inside of the fan blades so as to connect the fan blades together; a slit is formed between two circumferentially-adjacent fan blades of the cooling fan so that the two fan blades are connected only by the ring portion of the cooling fan; and in the resistance-welding step, a positive welding electrode and a negative welding electrode are respectively brought into contact with the two fan blades so that the cooling fan is held between the axial end face of the rotor core and both the positive and negative welding electrodes, and then weld current is supplied so as to flow from the positive welding electrode to the negative welding electrode, wherein the cooling fan further includes a pair of projections respectively provided in the two fan blades of the cooling fan so as to form two weld spots between the cooling fan and the axial end face of the rotor core, and in the resistance welding step, the positive and negative welding electrodes are respectively aligned with the two projections of the cooling fan in an axial direction of the rotating shaft and pressed against the cooling fan, thereby concentrating the weld current on the two projections.