Machine tool spindle bearings are bearings of precision machine tools and similar equipment, which are essential to ensure the working accuracy and performance of precision machine tools. The correct configuration of spindle bearings refers to the combination of bearing types and the arrangement of front and rear bearings, different configurations would affect different load capacity, operating speed, stiffness, temperature rise, and service life of the machine tool spindle.
Especially on the stiffness and temperature rise of the impact is more significant, so the configuration of spindle bearings should be based on the requirements of the machine tool’s working characteristics. From the function and structure, spindle bearings can be divided into two categories of rolling bearings and sliding bearings.
The purpose of running-in is for its roller and raceway can have good contact conditions before use, thus to keep the bearing has good contact accuracy, and avoid bearing a start in high speed and heavy load use caused by roller and raceway damage, so as to improve the life and accuracy of the bearing. The sliding between the roller end and the inner ring shoulder is caused because the tapered roller bearing is not a complete rolling contact, if the contact conditions are not appropriate, bearing damage happens easily. So for this kind of bearing, we should pay more attention to its running-in stage.
The mechanical spindle refers to the shaft on the machine tool that drives the workpiece or cutter to rotate. Spindle parts usually consist of the spindle, bearings, transmission parts (gears or pulleys), and others. In the machine, the main parts used to support the transmission are components like gears and pulleys; the main parts used to transfer motion and torque: machine tool spindles; some are used to clamp the workpiece, such as the mandrel. In addition to planers, broaching machines and other main motion for linear motion machine tools, most machine tools have spindle components. The motion accuracy and structural rigidity of spindle components are important determinants in determining the quality of machining and cutting efficiency.
Performance Comparison of Spindle Bearing Types
Spindle bearing is an important component in the spindle of CNC machine tools. In the process of spindle transmission, it can play the role of supporting the rotation of the mechanical body and reducing friction. Bearings will have a direct impact on the working performance of spindle components due to their different types, structures, configurations, and accuracy, as well as the degree of installation and adjustment. In terms of function and structure, spindle bearings can be divided into two categories: rolling bearings and sliding bearings. Sliding bearings can be divided into hydrodynamic bearings and hydrostatic bearings according to the way they generate oil film pressure.
