by 
In motorized spindle, the reliable operation of bearing is more important, which directly affects the performance index of machine tool. In addition to the influence of NTN bearing material, the selection of lubrication and cooling mode is also very important. To realize the high-speed cutting of the machine tool, first of all, the shaft speed should be high. High speed requires stable bearing performance. Lubrication is an important factor to ensure bearing performance. Using bearing oil-gas lubrication, the bearing can get good lubrication, the operation of motorized spindle is more stable, and good operation indexes can be obtained.
Among the factors affecting the speed and performance of motorized spindle, thermal deformation is related to lubrication.
The bearing size of motorized spindle is not too large and does not need a lot of lubricating oil to lubricate. If the traditional lubrication method uses a large amount of lubricating oil for intrusive lubrication, the method is not desirable, mainly because it can not provide good lubrication, NSK bearing. During the continuous circulation of lubricating oil, the oil temperature will rise due to the friction between oil molecules, which is not conducive to the operation of motorized spindle. Therefore, bearing oil-gas lubrication is selected. This micro lubrication method can reduce the supply of lubricating oil, not only avoid the heat generated by a large number of oil molecular friction, but also have better and better lubrication effect. For bearing oil-gas lubrication, the principle of single small amount shall be followed in oil supply. Each time, the oil shall be quantitatively supplied in a very small amount, and the oil supply frequency shall be increased to meet the lubrication requirements of the bearing. In this way, the compressed air drives the lubricating oil film to the friction surface. The lubricating oil fully plays the role of lubrication, and the compressed air can also take away the heat generated by friction and play the role of cooling.
1. The amount of lubricating oil consumed is low and the cost is saved,
2. The lubrication effect is good, which ensures the design performance of the motorized spindle,
3. Compressed air can take away the heat generated inside the motorized spindle and effectively prevent the bearing from deformation due to heat,
4. Positive pressure inside the bearing to prevent impurity intrusion, etc.