Strategy and practice for improving the rotation accuracy of machine tool spindle

1. Optimize the manufacturing and assembly of spindle components
Improve bearing accuracy
As a key component supporting the rotation of the spindle, the accuracy of the bearing directly determines the rotation accuracy of the spindle. Although traditional rolling bearings are widely used, multi-oil wedge dynamic pressure bearings or hydrostatic bearings are more suitable under high precision requirements. Multi-oil wedge dynamic pressure bearings form a dynamic pressure effect during rotation by designing a special oil chamber structure, effectively supporting the spindle and reducing friction, while hydrostatic bearings use an external oil supply system to form a stable oil film, further improving the rotation accuracy and rigidity. The application of these high-precision bearings significantly reduces the radial and axial runout of the spindle, providing a solid foundation for high-precision machining.

Improve machining accuracy
The machining accuracy of the spindle and its related components is also crucial. The surface machining of the box support hole, spindle journal, and parts that match the bearings must reach an extremely high level of accuracy. Advanced CNC machining centers and precision measuring equipment, such as three-coordinate measuring machines, are used to ensure that the dimensional accuracy, shape accuracy, and position accuracy of these components meet the design requirements. In addition, ultra-finishing technologies such as grinding and polishing are used to further refine the surface roughness and reduce the vibration and error caused by microscopic surface unevenness, thereby improving the rotation stability of the spindle.

Assembly precision control
Precision control during the assembly process is the last line of defense to improve the spindle rotation accuracy. Through high-precision measuring tools such as laser interferometers and roundness meters, the inner and outer rings of rolling bearings, spindle taper holes, etc. are strictly inspected to ensure that the preload adjustment before assembly is reasonable and the radial circle runout is controlled within the minimum range. During assembly, the "error compensation method" is used, that is, the principle of offsetting the small errors between the components is used to minimize the error after the overall assembly through precise adjustment, thereby effectively improving the rotation accuracy of the spindle.

2. Use advanced monitoring and maintenance technology
In addition to the optimization of manufacturing and assembly links, continuous spindle status monitoring and maintenance cannot be ignored. Vibration sensors, temperature sensors, etc. are used to monitor the operating status of the spindle in real time, and potential faults such as bearing wear and imbalance are discovered and warned in time. Combined with big data analysis technology, the collected data is analyzed to predict the life of the spindle, and maintenance plans are arranged reasonably to avoid downtime losses caused by sudden failures.

3. Innovative design and material application
With the advancement of materials science, the introduction of new high-performance materials has also provided a new way to improve the spindle rotation accuracy. For example, the use of carbon fiber composite materials to make the spindle can greatly reduce weight while maintaining high strength and high rigidity, which is conducive to reducing vibration and improving rotation accuracy. In addition, design innovations, such as the use of dual spindle structures or built-in spindle cooling systems, can also effectively deal with thermal deformation problems and maintain long-term stable operation of the spindle.