Machine tool spindle refers to the axis that drives the workpiece or cutter to rotate. It is usually composed of spindle, bearing and transmission parts (gear or pulley). In the machine, it is mainly used to support transmission parts such as gears and pulleys to transmit motion and torque, such as machine tool spindle; some are used to clamp workpiece, such as spindle.
In practical application, there are mainly two types of high-speed spindle: one is the high-speed motorized spindle with zero transmission. This kind of spindle should adopt the integrated structure of motor and machine tool spindle, and be subject to accurate dynamic balance correction. Therefore, it has good rotation accuracy and stability, but it has limitations on the output torque and power. The other is the spindle which combines the variable frequency spindle motor with the mechanical variable speed mechanism. The output torque and power of this kind of spindle are much larger, but the rotation accuracy and stability are relatively poor. Therefore, for this kind of spindle, how to correctly design the influence of the spindle and its components on the machining accuracy of the machine tool is very important.
The spindle needs regular maintenance, so as to ensure the stability and accuracy of machine tool processing. In the process of spindle processing, high temperature will be produced, which will reduce the working temperature of bearing. Lubricating oil is often used. There are two kinds of lubrication methods: oil air lubrication and oil circulation lubrication.
When using these two methods, we should pay attention to the following points:
1. When oil circulation lubrication is used, the oil quantity in the constant temperature oil tank of the spindle should be sufficient.
2. Oil air lubrication is just opposite to oil circulation lubrication. It only needs to fill 10% of the bearing space capacity.
The advantage of the circulating lubrication is that it can reduce the friction heat and absorb part of the heat of the spindle assembly under the condition of satisfying the lubrication. There are also two ways to lubricate the spindle: oil mist lubrication and spray lubrication.