| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor that can prevent a magnetic sensor to be arranged near an outer periphery of a magnet for detection from contacting the magnet for detection when a surrounding temperature varies, even if a linear expansion coefficient of the magnet for detection is different from a linear expansion coefficient of a magnet holder to which is fixed the magnet for detection.SOLUTION: In a motor, a speed detecting mechanism that detects rotation speed of a rotor comprises a magnet 17 for detection, a magnetic sensor 18 and a magnet holder 19. The magnet holder 19 comprises a shaft fixing part 19a to be fixed to a rotary shaft and a magnet fixing part 19b, formed to expand outward in a radial direction from the shaft fixing part 19a, to which is fixed the magnet 17 for detection. The magnet 17 for detection comprises a holder fixing part 17a to be fixed to the magnet fixing part 19b and a magnetization part 17b which is arranged closer to an outer periphery than the holder fixing part 17a and constitutes an outer periphery side of the magnet 17 for detection. Between an outer end of the magnet fixing part 19b and an inner peripheral face of the magnetization part 17b is formed a space S.SELECTED DRAWING: Figure 2 |
