Rotor of electric motor, and method for manufacturing rotor

Abstract

A rotor capable of preventing a magnet or a cover tube from being damaged by contacting a mold of an injection machine during production. The rotor includes a rotor core, a plurality of magnets arranged on the outside of the rotor core in the radial direction, a cylindrical cover tube surrounding the plurality of magnets, and resin charged to a gap defined between an outer peripheral surface of the rotor core and an inner peripheral surface of the cover tube. An axial dimension of the rotor core is greater than an axial dimension of each magnet, and an axial dimension of the cover tube.

1 . A method of producing a rotor of an electric motor, the rotor having a rotor core; a plurality of magnets arranged radially outside of the rotor core; a cylindrical cover tube surrounding the plurality of magnets; and the rotor having resin filled in a gap formed between an outer peripheral surface of the rotor core and an inner peripheral surface of the cover tube, wherein an axial dimension of the rotor core is greater than axial dimensions of the plurality of magnets and an axial dimension of the cover tube, the method comprising:
 arranging a plurality of magnets at radially outside of the rotor core;   arranging a cylindrical cover tube so as to surround the plurality of magnets;   contacting a first mold with an end face of the rotor core in one direction of an axial direction;   contacting a second mold formed with a resin-injection nozzle with an end face of the rotor core in the other direction of the axial direction, so that the resin-injection nozzle faces a gap formed between an outer peripheral surface of the rotor core and an inner peripheral surface of the cover tube, and that the second mold is separated away from end faces of the cover tube and the plurality of magnets in the other direction of the axial direction, toward the other direction of the axial direction; and   injecting the resin from the resin-injection nozzle into the gap.