The machine tool spindle refers to the axis on a machine tool that drives the workpiece. In the working process of a CNC machine tool, the workpiece is held by the spindle and directly participates in the surface forming motion. The spindle is the terminal execution key for CNC machine tools to realize cutting operations, and its rotational accuracy plays a very important role in the accuracy of the machine tool.
The structural forms of CNC machine tool spindle bearings are basically limited to four types: angular contact ball bearings, cylindrical roller bearings, double-direction thrust angular contact ball bearings, and tapered roller bearings .
Ceramic materials, due to their low density, high elastic modulus, low coefficient of thermal expansion, and resistance to wear and high temperatures, have become ideal materials for manufacturing high-speed precision bearings. Ceramic bearings have also been more widely used. Due to the difficult machining properties of ceramic materials, precision ceramic bearings are mostly hybrid ceramic ball bearings where the rolling elements are ceramic and the inner and outer rings are still made of chromium steel.
Generally speaking, when we mention CNC machine tool spindle bearings, ball screw bearings, and precision machine tool bearings, we are referring to spindle bearings and ball screw bearings with a precision of p5 or higher.
For rolling bearings used in general transmission bearings of CNC machine tools, the selection requirements are the same as for ordinary mechanical transmission bearings, as long as they meet the strength and life requirements and the speed does not exceed the specified limit speed.
