| 摘要 |
PURPOSE:To realize a remarkably small motor by making such a construction as uses the field magnetic flux of the motor body commonly with a speed detecting unit. CONSTITUTION:A rotor magnet 2 is integrally fixed to the lower portion of a disc 1 fixed to the shaft of rotation. The magnet 2 is a source of magneticism for generating a main magnetic flux for driving the motor. The windings 41 to 46 of an armature are flatly fixed to a stator magnetic path 3. A magnetic core 51, an AC energizing wire 61 and a magnet 81 constitute a transformer acting the main component of a detecting element for detecting the position and speed. A plurality of convex plates are fixed at an equal pitch to the side of the magnet 2, which faces the wirings 41 to 46. The change in the permeance of the magnetic path leading from one end of the core 51 through the convex plates 21 to the magnet 2 is detected by the wirings 41 to 46 so that the rotating speed is detected. That is to say, the speed can be detected with the use of the AC component of the magnetic flux of the magnet 2 in accordance with the existence of the convex plates 21. |
