| 摘要 |
PURPOSE:To reduce the moment of inertia and the number of assemly steps, by using a rotor gear and rotor sent to thrust and hold a magnet and providing a member of large friction efficient or the like on an engaged surface on the magnet to heighten the holding force of the holding surface. CONSTITUTION:A perforated columnar rotor magnet 4 is aligned to the a portion 5 of a rotor shaft. A gear portion 5a is provided at one end of the shaft portion 5. The end face of the gear portion facing the shaft portion has a slightly ground section 5b. The shaft portion 5 is tightly fitted in the center hole of a perforated disc- shaped rotor seat 6. A rotor magnet 4 is thrusted and fixed on the slightly ground sectopm 5b. Resin such as plastics of large friction coefficient is provided or surface treatment such as aventurine treatment is effected on the engaged surfaces of the magnet 4 and the rotor seat 6 to increase the clamping force on the magnet 4. This results in reducing the number of assembly steps and heightening conversion efficiency. |
