Analysis And Experimental Study On The Rotary Accuracy Of High Speed Grinding Electric Spindle Under Dynamic Load

The rotational accuracy of electric spindle is an important factor affecting the machining performance of machine tools.Accurate measurement and analysis of the rotational accuracy of the spindle during machining is one of the key technologies to ensure the machining accuracy of machine tools.Therefore,it is of great significance to carry out the testing and research on the accuracy change rule under the simulated load of the electric spindle working conditions for the optimization of machine tool process parameters,processing accuracy,and improvement of processing efficiency.This paper takes high-speed grinding motorized spindle as the research object.Firstly,the technical route for testing spindle rotation accuracy and thermal offset error was developed,and then the dynamic load simulation loading method for the spindle was determined.Finally,a spindle rotation accuracy testing platform under dynamic load loading was established,and a rotation accuracy evaluation software was developed to conduct experimental research on the variation law of spindle rotation accuracy under load simulation loading.The main research contents of this article are as follows:1.The definition of spindle rotation error and existing measurement methods,error separation methods,and rotation error evaluation methods are analyzed.A spindle spatial error model is constructed,which divides spindle errors into radial,axial,and tilt errors.The spindle rotation error signal is modeled and analyzed,and a peak to peak error separation method and an overall testing and evaluation method for spindle rotation accuracy are proposed.2.A dynamic load loading system for electric spindle is built.Firstly,analyze the grinding force law of the grinding electric spindle in actual working conditions.Secondly,by analyzing and comparing the advantages and disadvantages of various loading schemes,an electromagnetic exciter is used as a dynamic load loading device to simulate the load bearing situation of the spindle grinding condition.Finally,based on Lab VIEW software,a loading force acquisition program is designed as a loading force detection system to ensure the accuracy and reliability of spindle grinding load loading.3.A test bench for measuring the rotational accuracy of electric spindle considering dynamic load has been built.Firstly,determine the overall design scheme of the electric spindle rotation accuracy measurement test bench for dynamic loads.Secondly,building a collection device for spindle rotation error and thermal offset error can achieve measurement of spindle rotation error under dynamic load loading.Finally,the proposed spindle error separation and rotation accuracy evaluation method will be packaged and packaged,and a spindle rotation accuracy analysis and evaluation software will be developed using MATLAB software.4.An experimental study was conducted on the accuracy variation of electric spindle under simulated grinding load.According to the different factors that affect the spindle rotation accuracy,a corresponding test scheme is designed,and the obtained spindle accuracy variation rules are analyzed and summarized to obtain the influence rules of different factors on the spindle rotation accuracy.The rationality of the design of the spindle accuracy test bench and the reliability of the rotational accuracy analysis software are verified.