Conventionally, a wiper apparatus is mounted on a vehicle such as automotive vehicle, and configured to wipe off foreign objects such as rainwater and dust on a windshield. The wiper apparatus is provided with: wiper members provided on the windshield; and a wiper motor configured to swing the wiper members. By switching on a wiper switch provided in an interior of the vehicle, the wiper motor is rotated, thereby swinging the wiper members on the windshield. Since the wiper motor is installed in a small space covered by a cowl top panel, a brushless motor having a structure suitable for reduction in size and weight is employed.
Such a brushless motor is provided by a technique described in for example Japanese Patent Application Laid-Open Publication No. 2005-080451 (FIG. 1). According to the brushless motor (electric motor) disclosed in Japanese Patent Application Laid-Open Publication No. 2005-080451 (FIG. 1), ribs respectively having through-holes are formed on an outer periphery of a stator, and the ribs are pressed into a housing to fix the stator to the inner periphery of the housing. The number of the ribs is six and they are arranged at equal intervals in a circumferential direction of the stator. The ribs reduce a press-fitting load of the stator to the housing, and suppress the distortion of the housing and of the stator, thereby preventing a drop in efficiency of the electric motor.
USPTO Backgrounds
USPTO Backgrounds