Electric motor with earth plate press fitted to motor casing

Abstract

A motor comprising a small case having at the center thereof a cylindrical bearing housing for housing a bearing, and at the edges thereof holes through which brush holders receiving and supporting motor terminals connected to brushes extend. A large case forming a motor housing, a earth plate comprising a base having at the central part thereof a contacting and mounting hole into which the bearing housing is inserted and press-fitted, a neck extending from the base flush therewith, an arm extending from the tip of the neck at right angles to the plane of the neck and being inserted into a motor terminal hole on one of the brush holders and a contacting curved portion for making electrical contact with the motor terminal. The earth plate is installed onto the small case by press-fitting the base from the outside to the bearing housing, and press-fitting the arm into the motor terminal hole so as to make electrical contact with the motor terminal. The bearing housing being adapted to be press-fitted to the contacting and mounting hole of the earth plate by providing one or three straight cut portions as necessary on the contacting and mounting hole, or making the contacting and mounting hole of a slightly smaller diameter and providing a plurality of notches or recesses or projections; or by providing a cap, fitted with an air vent hole, on the contacting and mounting hole of the earth plate.