Bearing to reduce the thermal deformation of machine tool

Under the influence of internal and external heat source, machine tool parts will be different levels of heat deformation, make the relative motion relationship between the workpiece and tool was broken, and machine tool quarterly decline. For nc machine tool, because all the processing process is calculated command control, the influence of thermal deformation is more serious. In order to reduce the thermal deformation, usually adopt the following measures in the structure of nc machine tools. 1. Reduce fever machine internal heat produced when the main heat source of hot deformation, should as far as possible to the heat source is separated from the host. 2. Control temperature rise after took a series of measures to reduce the heat source, thermal deformation situation will improve. But to completely eliminate machine internal and external heat source is often very difficult, even impossible. So must be good to control the temperature of cooling and cooling, in order to reduce the influence of heat source. Which department is in the machine tool is a effective method of forced cooling heating parts, also can be in low temperature machine parts, by using the method of heating machine each point temperature uniformity, so that we can reduce the buckling deformation caused by temperature difference. 3. Improving mechanism under the condition of same fever, machine body has a great influence on the thermal deformation is also. Such as nc machine tools in the past using single mast mechanism may be replaced by double column body. Due to the left and right sides is symmetrical, dual axis line of the mast mechanism after heated in addition to produce the vertical translation, other direction deformation is small, and vertical axis movement can easily use a coordinate correction to compensate. For CNC lathe spindle box, should try to make the spindle thermal deformation occurred on the cutter cuts the vertical direction. This can make the spindle thermal deformation reduced to minimal impact on machining diameter. In structure should also minimize the spindle center and the main shaft to the distance of the ground, in order to reduce the amount of the thermal deformation, at the same time should be made before and after the temperature rise of headstock is consistent, to avoid the main shaft deformation after the tilt. Ball screw in numerical control machine tool in large load, high speed and poor heat dissipation is expected under the conditions of work, so the screw easy to fever. Ball screw heat production and the consequences are serious, especially in the open loop system, it can make the loss of positioning accuracy of feed system. Some current machine with pretension method to reduce the thermal deformation of a ball screw. For the above measures still cannot eliminate thermal deformation, can be made by CNC system according to the results of the measurement compensation pulse were revised.