PURPOSE: To easily press-fit and secure a stator core and to enhance reliability by providing a suitable number of small protrusions on the outer periphery of the core, and press-fitting and fixing it to a frame.
CONSTITUTION: Four sharp protrusions 22 each having 0.1∼0.4mm of height are provided on the peripheral edge of a core 21, and simultaneously shaped at the time of press punching. The core 21 is laminated and secured by a calking method. Thereafter, the stator core having such sharp protrusions 22 on the outer periphery is press-fitted to a frame made of aluminum or the like. According to the method, since an anti-rotation is conducted by the protrusions 22, it is not necessary to provide a large clamping margin in the profile of the core and the bore of a frame, and since the protrusion 22 is sharp at its end, it can be easily inserted in case of press-fitting the core 21 to the frame. After the insertion, the sharp protrusions 22 of the outer periphery of the core are intruded to the frame, thereby effectively anti-rotating it.
SUZUKI TSURUJI
SHIMOJO NORIO
