| 摘要 |
PURPOSE:To reduce the inertial moment of a rotor of a step motor for a watch by forming a plurality of holes at the periphery of the central hole of a rotor seat, thereby reducing the weight of the rotor seat. CONSTITUTION:A rotor seat 2 made of aluminum series material is formed with a curved or tapered surface for facilitating the press-fitting of a rotor magnet 1 made of intermetallic compound and a central hole to which the shaft of a rotor rotating shaft 3 is press-fitted. A plurality of escape holes 4 are formed in balancedly to reduce the inertial moment of the rotor seat 2 from the lower surface of the outer periphery of the central hole of the rotor seat 2. |
