Research On Multi-load Simulation Loading System Of Motorized Spindle Based On Cutting Load

Motorized spindle is a highly integrated mechatronics product,as one of the core components of CNC machine tools,its accuracy,life,quality and reliability level directly affect the performance of the whole machine.At present,the research on the reliability of motorized spindle mainly focuses on the field tracking and the no-load or single load research under laboratory conditions,and most of them are separated from the real load conditions of motorized spindle.Therefore,this paper uses the electric cylinder,electromagnetic exciter and electric dynamometer as the loading equipment,combined with the load spectrum of motorized spindle,from the mechanical system,the electric cylinder,electromagnetic exciter and electric dynamometer as the loading equipment,The control system and monitoring system have carried out the research on the multi working condition simulation loading system of motorized spindle.Through the comparative study of experiment and theoretical model,the loading accuracy of radial force,axial force and torque of the system under the working conditions of milling,drilling and boring is obtained,which provides a large number of accurate test data for the reliability research of motorized spindle,So it is very important to study the quality and reliability of motorized spindle and improve the performance of motorized spindle and the whole machine.The main research contents are as follows:1.Load spectrum analysis and load extrapolation of motorized spindle.Based on the eight stage multi working condition dynamic comprehensive load spectrum,the load spectrum of motorized spindle is studied by using the envelope principle of bivariate normal distribution function,and the envelope extrapolation of load spectrum is carried out.The results show that the radial load range of load envelope spectrum is0-3800 N,the axial load range is 0-2100 N,and the torsional load range is 0-35N·m.It provides the design parameters and experimental basis for the design of the full working condition simulation loading system and the loading test scheme of the motorized spindle.2.Design of multi working condition simulation loading system for motorized spindle.The new design of multi working condition simulation loading system of motorized spindle is carried out from mechanical system,control system and monitoring system,and the optimization improvement of the system in mechanical composite decoupling is described in detail.Compared with the previous test system,the whole system adopts all electric equipment loading,multi flexible mechanism for force transmission and intelligent load test and control monitoring platform,which makes the new generation of motorized spindle multi working condition simulation loading system more safe,reliable,intelligent and accurate.3.Experimental research on multi working condition simulation loading system of motorized spindle.Based on the orthogonal test of range analysis method,a detailed test scheme is developed.It is concluded that the radial force,the axial force and the torque have the greatest influence on the change of spindle rotation center displacement under milling,drilling and boring conditions,The results show that the coupling effect of the three forces is very weak,which can be ignored.Then the radial force,axial force and torque are separately loaded.The results show that the average change rate of radial force on the rotation center displacement of motorized spindle is 9.73?m/300 N and2.26?m/100 N respectively under milling and boring conditions;Under the drilling condition,the average change rate of the axial force on the displacement of the rotary center is 0.38?m/300 N.The average change rate of torque on the speed is-66.68rpm/5N·m,which provides the measured data for the comparison between the theoretical model and the later one.4.Research on Modeling of multi working condition simulation loading system of motorized spindle.Through systematic force transfer analysis,based on the radial force node element model,axial force loading model and measured torque loading value,the experimental value and theoretical value are compared.The results show that the maximum loading accuracy of milling is 81%,and the minimum is 77%;The overall loading accuracy is about 79%;The highest boring accuracy is 74%,the lowest is 56%,and the overall loading accuracy is about 65%;The accuracy of axial force loading is low,so the structure should be optimized;The results show that the variation of torque and rotational speed is approximately inversely proportional,and the accuracy of torque loading is high.