In addition to the softening of the bearing support, the centrifugal force also causes the softening of the rotating shaft, and the softening of the rotating shaft is the main reason for the reduction of the natural frequency of the electric spindle system; the gyro torque divides each natural frequency of the spindle system into two modes, front and rear modes, The law of state changes with speed is different.

On the basis of considering the effects of high-speed inertia effects such as centrifugal force and gyro torque on the bearing and rotating shaft of the electric spindle, the dynamic model of the bearing-rotor system of the high-speed electric spindle is established, and the natural frequency of the electric spindle modal test is carried out. According to the theory and test results The following conclusions can be drawn:

1. The high-speed inertia effect will cause the ball bearing to soften and reduce its supporting rigidity. The higher the speed, the more obvious its effect.

2. The softening of the shaft caused by centrifugal force will reduce the natural frequency of the electric spindle system; the gyro torque divides the spindle system into two modes, the front mode frequency decreases with the increase of the speed, and the rear mode frequency increases with the increase of the speed. Rising; the change in the natural frequency of the system caused by the effect of high-speed inertia on the shaft is greater than that caused by the effect on the bearing.

3. According to the theoretical model, the theoretical value of the natural frequency of the system under each working condition and the experimental value obtained from the test are in good agreement, indicating that the built model has a certain guiding effect on the analysis of the dynamic behavior of the high-speed electric spindle bearing-rotor system.