The precision electric spindle is mainly composed of components such as a housing with a cooling system, stator, rotor, bearings, etc. During work, speed can be increased or decreased by changing the frequency of the current. Because precision electric spindles require high-speed operation, the quality of some components directly affects the performance of the electric spindle:

1. Rotating shaft

This component is the main rotating body of the precision electric spindle. The manufacturing accuracy directly affects the final accuracy of the electric spindle. The dimensional tolerance and accuracy requirements of the finished shaft are very high. When the shaft rotates at high speed, the eccentric mass will cause vibration, seriously affecting its dynamic performance. Therefore, it is necessary to conduct strict dynamic balancing tests on the shaft. Parts partially installed on the shaft should also undergo dynamic balance testing along with the shaft.

2. High speed precision bearings

Because the maximum speed of the electric spindle depends on the function, size, arrangement, and lubrication method of the bearings, this type of bearing needs to have the advantages of good high-speed performance, high dynamic load bearing capacity, good lubrication performance, and low heat generation. In recent years, dynamic and static pressure bearings, ceramic bearings, and magnetic levitation bearings have been developed successively. Dynamic and static bearings have high stiffness and damping, which can significantly improve machining efficiency, machining quality, extend tool life, and reduce machining costs; And this lifespan is semi infinite. The maglev spindle has good high-speed performance, high accuracy, and is easy to diagnose and monitor online. However, this type of electric spindle has not been widely used due to its complex electromagnetic measurement and control system, high price, and long-term high level. Currently, ceramic bearings are widely used in the market. Generally, the inner and outer rings of angular contact ceramic bearings are made of steel rings, and the rolling elements are made of ceramic materials. Ceramics have the advantages of low density, good rigidity, and low coefficient of thermal expansion. In addition, theoretical calculations, contact fatigue tests, and crushing tests have shown that the first failure site of hybrid ceramic bearings is the steel ring rather than the ceramic ball. Because the theoretical lifespan of the first three types of bearings is infinite, especially magnetic levitation bearings, which also have advantages such as automatic adjustment of eccentricity, in the future ultra high speed machine tool market, with the development of technology, magnetic levitation bearings should be the direction of development. In general high-speed machining machines, hybrid ceramic bearings or pure ceramic bearings also have a wide range of applications.

3. Lubrication system

The use of a good lubrication system has a significant impact on the performance of precision electric spindles. Typical lubrication methods include oil mist lubrication or gas oil mixture lubrication. The former mainly atomizes lubricating oil to lubricate bearings, which cannot be recycled and causes serious air pollution. The latter uses high-pressure air to directly blow lubricating oil into the bearing, providing lubrication while also dissipating heat.