The correct configuration of self-aligning roller bearings refers to the combination of bearing types and the arrangement of front and rear bearings. Different configurations determine the different load capacity, operating speed, stiffness, temperature rise, and service life of the machine tool spindle, especially the impact on stiffness and temperature rise is more significant. Therefore, the spindle bearings should be reasonably configured according to the requirements of the machine tool\'s working characteristics. In terms of function and structure, spindle bearings can be divided into two categories: rolling bearings and sliding bearings.

The purpose of running in operation is to ensure that the roller and raceway of the bearing have good contact conditions before the formal angle adjustment, in order to maintain good contact accuracy of the bearing and avoid damage to the roller and raceway during high-speed and heavy-duty use, thereby improving the life and accuracy of the bearing. Due to the incomplete rolling contact of tapered roller bearings, there is sliding between the roller end face and the shoulder of the inner ring. If the contact conditions are not good, it is easy to cause biting damage. Therefore, running in operation should be given more attention to this type of bearing

Mechanical spindle refers to the axis on a machine tool that drives the workpiece or tool to rotate. The main shaft components are usually composed of a main shaft, bearings, and transmission parts (gears or pulleys). In machines, it is mainly used to support transmission parts such as gears and pulleys, transmit motion and torque, such as machine tool spindles; Some are used to clamp workpieces, such as spindles. Except for machine tools with linear motion such as planers and lathes, most machine tools have spindle components. The motion accuracy and structural stiffness of spindle components are important factors determining machining quality and cutting efficiency