Electric spindleIt is a high-precision actuator, and the main factors affecting the rotation accuracy of the electric spindle are:

1. Electric spindle errors mainly include roundness errors of the spindle support journal, coaxiality errors (spindle axis deviation), and vertical errors between the spindle journal axial bearing surface and the axis (axial motion affecting axial motion). Main axis).

2. Electric spindle bearing error

Bearing errors include roundness errors in the inner holes of sliding bearings or rolling bearing raceways, waviness errors in the inner rings of sliding bearings or rolling bearing raceways, shape and size errors in rolling bearings rollers, perpendicularity of bearing positioning end faces and axes, and bearing end faces. The parallelism error between bearings, bearing clearances, and deformation of forces during cutting processes.

Radial unequal stiffness and thermal deformation of the 3 spindle system

From the above, it can be seen that the main reasons affecting the rotation accuracy of the electric spindle are bearing wear, shaft and contact surface wear. Due to the integration of the motor into the spindle unit and the high speed of the electric spindle, a large amount of heat is generated during operation, resulting in an increase in the temperature of the electric spindle. This deteriorates the thermal state and dynamic characteristics of the electric spindle, thereby affecting its normal operation. Therefore, certain measures must be taken to control the temperature of the electric spindle and keep it constant within a certain value. At present, machine tools generally use forced circulation oil cooling to cool the stator and spindle bearings of the electric spindle. The cooling oil through the oil cooling device is forced to circulate outside the main shaft stator and the main shaft bearings, thereby taking away the heat generated by the high-speed rotation of the main shaft. In addition, in order to reduce the heat generated by the spindle bearings, the spindle bearings must be properly lubricated.