The winding phases of high-speed electric spindle motors are 120 ° out of phase with each other. After three-phase alternating current, the three-phase winding forms a sinusoidal alternating magnetic field. Three symmetrical alternating magnetic fields are superimposed on each other to form a constant intensity. The magnetic field rotates at a constant speed in a certain direction, and the magnetic field speed is the synchronous speed of the electric spindle. The synchronous speed n of an asynchronous motor is determined by the frequency f of the input stator winding current of the motor and the number of poles P (n=60f/p) of the motor stator. The electric spindle is obtained by changing the frequency and excitation voltage of the current input to the stator winding of the motor.

During acceleration and braking, perform acceleration and deceleration by changing the frequency to prevent the motor from becoming too high. Due to the fact that the direction of the rotating magnetic field of the electric motor depends on the phase sequence of the three-phase AC power input to the stator, changing the phase sequence of the input current of the electric spindle can change the direction of rotation of the electric spindle. Electric spindle is a new technology that integrates machine tool spindle and spindle motor in the field of CNC machine tools in recent years. Combined with linear motor technology and high-speed cutting tool technology, it will drive high-speed machining into a new era. Electric spindle is a set of components, including electric spindle and its accessories: electric spindle high-frequency inverter, oil mist lubricator, cooling unit, built-in encoder, tool changer. The electric spindle itself directly installs the hollow motor rotor on the spindle, and the stator is fixed in the hole of the spindle box through a cooling sleeve, forming a complete spindle unit. After applying current, the rotor directly drives the spindle for operation.