Research On Measurement Of Rotating Error Of Ultra-Precision Spindle

In the measurement of rotating error of spindle, surface errors of the test piece ismixed with the rotating errors inevitably, in the case of the measurement ofultra-precision spindle, the mixed surface errors shouldn't be neglected, therefore,Research on the measurement of rotating errors is focused on Error SeparationTechniques.This paper studies on theUltra-Precisionaerostatic bearing's spindle. On the basisof the research on the three main Error Separation Techniques, this paper combinesthe traditional bidirectional measurement with Error Separation Techniques of thereversal-direction measurement, and applies a simple and accurate measurement ofrotatingerrortorealizeerrorsseparation.Firstly, theories of shaft rotating error are studied. The research is focused on theperiodicalsignaloftheshaftrotatingerror.Fourierpolynomialisusedtodescribetheperiodicalsignalfunction.Secondly, components of the measurement errors of single-point bidirectionalstandard ball are analyzed. Fourier transform is applied to separate the EccentricErrorofthestandardball.Reversalmethodisappliedtoseparatethesurfaceerrorsofstandard ball. Multi-angle measurement is applied to separate the radial errors fromtheaxialerrors.Thirdly, measurement system of rotating errors of ultra-precision shaft system ,including standard ball,ultra-precision,capacitance micrometer and otherinstruments are designed. Electrical Control System composed of touch panel andPLC is designed. Pure-couple flexible Coupling is designed to reduce the EccentricErrorandvibrationerrorcausedbytheshaftconnecting.Error Evaluation of Roundness and rotating errors is studied. The methodof LeastSquaresisusedtoevaluatetherotatingerrorofspindle.A Visual Basic programming is used to complete the complex data operation oferrorseparationandtoevaluatetheerrorfinally.Astatic model is established to analyze the relationship between the roundness ofaerostatic bearing's spindle and rotating error of the shaft system. Errorhomogenization coefficient of the aerostatic bearing's spindle system with different numbers of Orifices is obtained. Error analysis is applied to the measurement.Accuracyofthismeasurementsystemisprovedbytheoreticalanalysis.Orthogonal experiment is applied to analyze the experiment outcome. Severalkinds of factors influencing the rotating error are analyzed. The experiment outcomeproves the fact that roundness of the shaft is the main influencing factor. And theaccuracy of the measurement system and preciseness of the static model are alsoprovedbytheexperiment.