Permanent magnet motor

A permanent magnet motor, comprising:

• an armature;
• a rotor;
• and
• an angle detector,
• wherein the armature includes:
• an armature iron core;
• and
• an armature winding,
• wherein the rotor includes:
• a rotor iron core;
• and
• a permanent magnet
• wherein the angle detector includes:
• a sensor magnet;
• and
• a semiconductor sensor,
• wherein the rotor iron core including the permanent magnet is fixed to a rotation shaft,
• wherein the sensor magnet is magnetized into two poles and is provided in an end portion of the rotation shaft, and has the same rotation center as a rotation center of the rotation shaft,
• wherein the semiconductor sensor is opposed to the sensor magnet in an extension direction of the rotation shaft;
• wherein the semiconductor sensor and the sensor magnet have a gap formed therebetween, and
• wherein a plate member made of a magnetic substance is provided between the semiconductor sensor and an end portion of the armature iron core on the semiconductor sensor side.