Motor capable of adjusting phase difference between output signals

摘要

A motor capable of performing mechanical position adjustment of a magnetic detection unit to thereby adjust a phase difference between signals output from respective two magnetosensitive pole pieces. A rotor includes a magnet having an axial end surface magnetized to have circumferentially alternately different poles. A stator has two outer magnetic pole portions opposed to an outer peripheral surface of the magnet. Two coils are energized to excite the outer magnetic pole portions. A magnetic sensor is opposed to an axial end surface of the magnet. The magnetosensitive pole pieces of the magnetic sensor detect a magnetic field change caused by rotation of the magnet. The magnetosensitive pole pieces are arranged side by side in a direction orthogonal to a diametrical direction of the magnet. The position of the magnetic sensor can be adjusted in the diametrical direction of the magnet.

主权项

1. A motor comprising:
a rotor configured to be rotatable about a shaft and including a magnet having an axial end surface and an outer peripheral surface, on each of which different poles are alternately arranged in a circumferential direction thereof; a stator formed of a soft magnetic material and including magnetic pole portions opposed to the outer peripheral surface of the magnet; a plurality of coils configured to be energized to thereby excite the magnetic pole portions of the stator; a magnetic detection unit which has a first magnetosensitive portion and a second magnetosensitive portion for detecting a magnetic field change caused by rotation of the magnet; and a holding member configured to hold the magnetic detection unit, wherein the holding member holds the magnetic detection unit such that the first magnetosensitive portion and the second magnetosensitive portion are opposed to the axial end surface of the magnet, wherein the holding member holds the magnetic detection unit such that a midpoint line between the first magnetosensitive portion and the second magnetosensitive portion of the magnet detection unit extends through a center of the shaft of the rotor, wherein the holding member holds the magnetic detection unit such that the magnetic detection unit is adjustable in a diametrical direction of the magnet without changing a space between the first magnetosensitive portion and the second magnetosensitive portion of the magnet detection unit, wherein the first magnetosensitive portion and the second magnetosensitive portion are provided in a single unit, and wherein the single unit is disposed in a single opening of the holding member.