| 摘要 |
<p>In a variable speed controllable induction motor which has a unitary rotor (2) having a plurality of rotor cores (2A,2B) provided thereon with rotor conductive members (5) short-circuited by resistive members (r), a plurality of stators (25,26) surroundingly facing the respective rotor cores (2A,2B) and a phase shifter (60) producing phase differences between the voltages induced on separate portions of the conductive members (5), there are provided a phase difference detector (92) or rotated position detector (92A,92B,92C,92D), a rotations number detector (91), and a control device (70). The control device (70) calculates the necessary amount of operation of the phase shifter (60) for starting the motor or for effecting the speed changing operation thereof during the operation based on a phase difference detected by the phase difference detector (92) or the rotated position detector (92A,92B,92C,92D) and the actual number of revolutions of the rotor (2) detected by the rotations number detector (91), and, thus, the operation of the phase shifter (60) driven by a driving device (50) is automatically and quickly controlled until the actual number of revolutions reaches the desired number of revolutions set by a revolutions number setting device (94).</p> |
