Motor and drive control system thereof

Abstract

Provided is a motor having a magnetic polar unit in which a permanent magnetic polar array having arranged therein alternately a plurality of permanent magnetic polar elements in alternate opposite poles is made to face a plurality of electromagnetic coil arrays alternately excited at opposite poles, and the permanent magnetic polar array is made to move thereby; wherein the motor further comprises a sensor for detecting the periodical magnetic change accompanying the movement of the permanent magnetic polar array, the output of the sensor is directly returned as a direct drive waveform to the electromagnetic coils, and this drive circuit forms the excitation signal based on the return signal.

1 . An electric motor comprising: 
 a movable body with a plurality of permanent magnets, alternately magnetized at opposite polarities, disposed thereon;    a stator having an array of electromagnetic coils disposed so that they do not come into contact with the movable body;    a drive circuit that moves the movable body based on the attraction/repulsion between the movable body and the electromagnetic coils generated by supplying an excitation current to the electromagnetic coil array to alternatively magnetize the electromagnetic coils in the electromagnetic coil array at opposite polarities; and    a magnetic sensor, disposed at a position fixed with respect to the electromagnetic coil array, that linearly detects the periodic magnetic field change caused by the movement of the permanent magnets and outputs an analog value,    wherein the drive circuit creates a pattern for exciting the electromagnetic coils by performing PWM control on the output analog value of the sensor, and directly supplies the electromagnetic coils with that pattern.    
   
   
       2 . The electric motor according to  claim 1 , wherein when the electric angle between the electromagnetic coils at opposite polarities is 2π, the sensor is able to linearly detect the position of the moveable body in the 2π area.  
   
   
       3 . The electric motor according to  claim 2 , further comprising an amplifier that amplifies the output analog value of the sensor.  
   
   
       4 . The electric motor according to  claim 1 , comprising a pair of said stators, wherein the movable body is disposed between the pair of stators.