| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor which can retain a rotor structure surely in the specified position in axial direction without applying excessive axial force (thrust force) to a thrust bearing. SOLUTION: For a motor, the rotor body 5 of a rotor structure 7 integrated with a motor shaft 8 is confronted in axial direction with a stator 4, and the motor is equipped with an axial force applying means (a permanent magnet 23 and a peripheral wall 18 made of soft magnetic material) which exerts such axial force F as to about the end 8a on bearing side of the motor shaft 8 against the thrust bearing 12 within the bearing housing 10 of a chassis structure 2 upon the rotor structure 7, between the rotor structure 7 and the chassis structure 2. For the axial force applying means (a permanent magnet 23 and a peripheral wall 18 made of soft magnetic material), the upper section 27 than the section A of the permanent magnet 28 confronts in diametrical direction the peripheral wall 18 made of soft magnetic material, so that the axial force F may be smaller as the end 8a on bearing side comes closer to the thrust bearing 12 when the end 8a on bearing side of the motor shaft 8 is near the thrust bearing 12.
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