ROTOR FOR ELECTRIC MOTOR, ELECTRIC SUPERCHARGER, AND ELECTRIC-MOTOR ASSISTED SUPERCHARGER

摘要

Embodiments of the present invention relate to a rotor for an electric motor, and an object of some embodiments is to maintain a rotor sub-assembly at an appropriate position without using a spacer and without applying excessive compressive stress to a magnet. A magnet and an end-plate are press-fitted into a ring-shaped member to form a rotor sub-assembly. A shaft is passed through the rotor sub-assembly. A nut is fastened onto the shaft, and fixes the axial position of the rotor sub-assembly with respect to the shaft. The shaft includes a step at which the shape of the shaft changes between a small-diameter portion and a large-diameter portion. An end face of the large-diameter portion that is exposed to outside of the small-diameter portion is adopted as a reference face. The end-plate is mounted to the ring-shaped member so as to oppose an axial end portion of the magnet. The end-plate includes a positioning portion that allows insertion of the small-diameter portion, contacts the reference face at an opposing face, and receives a fastening force produced by a nut at a pressure receiving face.

主权项

1. A rotor for an electric motor, comprising:
a ring-shaped rotor sub-assembly including a ring-shaped member, a magnet and an end-plate; a shaft that passes through the rotor sub-assembly; and a fastening member that is fastened to the shaft, and that fixes an axial position of the rotor sub-assembly with respect to the shaft; wherein: the magnet is disposed between the ring-shaped member and the shaft so as to contact an inner wall of the ring-shaped member; the shaft includes a step at which a shape of the shaft changes between a small-diameter portion and a large-diameter portion, and a reference face that is an end face of the large-diameter portion that is exposed to outside of the small-diameter portion; and the end-plate is mounted to the ring-shaped member so as to oppose an axial end portion of the magnet and has a positioning portion, said positioning portion includes an opposing face contacting the reference face and said positioning portion includes a pressure receiving face receiving a fastening force produced by the fastening member, and said small-diameter portion is inserted into the positioning portion.