Design Of The Aerostatic Spindle And Study On Its Key Techniques

Super-precision machining technology is a kind of significant technology which supports modern high-tech war. It is the basis for the development of high-tech industry and it is the development direction of modern manufacturing technology. The super-precision machining technology is the key point in the super-precision machine tools. Many developed countries are concentrating on developing super-precision machine tools. As one of the most pivotal assemblies in super-precision machine tools, the key parts' machining accuracy and assembly precision of the aerostatic spindles have an important effect on its performance. By far, high-speed and super-precision aerostatic spindle have created great challenge for the key parts processing and assembly. Therefore, it is important to study the key parts' processing and assembly technology of the aerostatic spindle.Taking a kind of aerostatic spindle designed by ourselves as an example, the paper takes research into how the key parameters affect the aerostatic spindle' bearing capacity and stiffness, and explores the super-precision processing technology of the key parts. It takes research into the assembly technology and testing methods and gives the aerostatic spindle's theoretical bearing capacity and stiffness curve, at last, the static performance of the aerostatic thrusting bearing is tested. The main research jobs are as follows:1.The structure of the aerostatic spindle is designed, and the key parameters is calculated, which is mainly based on the fundamental principle of aerostatic lubrication.2.The paper analyses the bearing capacity and stiffness of the aerostatic bearings. It takes research into how the diameter, length, radial clearance, radius of orifice restrictor and throttle ratio of the aerostatic radial bearing and the diameter, slit width and clearance of the aerostatic thrust bearing affect the bearing capacity and stiffness. The result of research indicates that, when such appearance size as the diameter and the length of the aerostatic bearing increases, the bearing capacity and stiffness will go up. When the relative size between the radial clearance and the diameter of the throttle of the aerostatic radial bearing and the relative size between the gap and slit width of the aerostatic thrust bearing is designed reasonably, the stiffness will go up. The effect of the key parameters on the bearing capacity and stiffness of the aerostatic bearing validates the accuracy of calculation of the key parameters for the aerostatic bearing, and provides a kind of theoretical support for the future design of aerostatic bearings.3.The paper takes research into the processing technology for the key parts of the aerostatic spindle. The static push plate and shaft are the key parts of the aerostatic spindle. A kind of compensate process for the key parts is put forward which is based on the analysis of the error sources. When the key parts are machined according to the anti error form, the flatness of the static push plate converges to 0.98?m and the cylindrical degree of the shaft converges to 2.3?m, which has engineering significance to the manufacturing of key parts of the aerostatic spindle.4.The paper takes research into the assembly process of the orifice restrictors, the assembly process of the aerostatic bearings and the testing methods of the aerostatic spindle. At last, the paper gives the aerostatic spindle's theoretical bearing capacity and stiffness curves and the static performance of the aerostatic thrust bearing, which supplies guide for the assembly and performance test of the aerostatic spindle.