Hitachi Koki Co., Ltd.

Satoru Gunji

Tomoyoshi Yokota

Teruo Imai

Hirokazu Yoshida

In a circular saw, an end plate provided on an end of a rotor core has a cylindrical shaft insulator and a plate extending radially from the shaft insulator. The plate is disposed at a position separated from the end of the rotor core. The plate includes slot parts, and air holes that penetrate the plate in the axial direction of the rotor shaft at areas adjacent to the rotor shaft. Protruding parts are provided on the shaft insulator on both sides of each air hole, extending in the axial direction of the rotor shaft and protruding radially outward with respect to the rotor shaft. The shaft insulator has an outer diameter Dthat is smaller than a diameter Dof the plate in the slot parts adjacent to the rotor shaft.

Electric motor and electric tool having the motor

In the portable electrical circular saw (electrical tool) in which a commutator motor (permanent magnet motor) is mounted in a motor case (housing) which is integrally formed in a tube shape, the commutator motor includes a stator fixed to an inner circumferential surface of the motor case and a rotor which is rotatably disposed in the stator, and a plate having a plurality of protrusions is disposed on at least one of the both axial ends of a rotor core of the rotor, an outer diameter of at least two protrusions of the plate is larger than an outer diameter of the rotor core and smaller than an inner diameter of the stator.

Growing community of inventors

Hitachinaka, Japan

Satoru Gunji