Structural Design And Performance Analysis Of Aerostatic Motorized Spindle With Orifice Throttling

Aerostatic motorized spindle integrates the motor and the spindle core,and with aerostatic bearing as support.It has been widely used in the field of ultra-precision manufacturing technology,due to its advantages of high precision,high speed,cleanliness and low friction loss.To improve its performance is significant to the upgrade of modern manufacturing industry.The structures and functions of aerostatic motorized spindle are various.This paper takes aerostatic spindle with orifice throttling as study object,proposes one kind of aerostatic motorized spindle structure with adjustable axial force,studies the analysis methods of bearing capacity,stiffness and other important parameters,verifies the availability of key parameters analysis methods by experimental,based on the platform set up from spindle performance experimental test had been done.The study of this paper is mainly at the following four aspects:(1)Analyze the structure of the spindle,put forward aerostatic motorized spindle structure with adjustable axial force.And study the analysis methods of spindle parameters in accordance with the fundamental principle of aerostatic lubrication.(2)Analyze the performance of aerostatic thrust bearings by numeral calculations based on FDM and fluid simulation calculation based on FVM,to explore the influences of some key parameters,such as orifice diameter,film thickness,and air pressure,on the bearing capability and stiffness.The results show that,the result data of theoretical calculation is quite different with simulation calculation,when the film thickness is less than 15?m.And it's similar when the film thickness is between 15?m and 30?m.(3)Analyze the performance of aerostatic radial bearings,by numeral calculations based on FDM and fluid simulation calculation based on FVM.And analyze the influences on bearing capability and stiffness caused by orifice diameter,film thickness,air pressure,speed and eccentricity.It indicates that,for the influences on radial bearings,the development trend is similar,but the data values are different in accordance with the changes of air pressure and eccentricity.And the results of orifice diameter variations are quite different under different experimental methods.(4)Set up the platform for the performance experimental test of spindle,design the methods of both contact loading and non-contact loading to test the spindle performance,and compare the experimental results with the above-mentioned results of spindle parameters analysis methods to provide a reference for the design and parameters analysis of aerostatic motorized spindle.