Research On The Establishment Of Coordinate System For Large Gear Measurement System

As an indispensable part of the large-scale equipment,the large gear is widely used in the fields of ships,generator sets,mining machinery,aerospace and other fields,and plays a very important part in national economy and national defense construction.Therefore,the detection technology for guaranteeing the quality of large gear manufacturing is of great value.In this paper,the problem of establishing the coordinate system is studied and analyzed.Through comparison and analysis of several schemes,the standard gauge block method is proposed to design the measuring coordinate system scheme.This paper also analyzes the influence of each error sensitive item on the establishment of the measuring coordinate system.The result is proved by the experiment.The main research contents are as follows:(1)The overall scheme of measuring coordinate system is designed.In this paper,three methods of the measuring coordinate system are proposed.They are the standard gauge block method,the small circle method and the multi station measurement.Through the comparative analysis of a variety of programs,the standard gauge block method is proposed.This method improved the measuring accuracy of the coordinate system.(2)The accuracy of the standard gauge block method is analyzed.The influence of error-sensitive items on the coordinate system establishment are studied,such as Indication error,geometric error of measuring block,geometric error of measuring movement,tilt error of worktable and installation error of measuring block.Respectively,the sensitive items of the error measurement model is established.The error model is analyzed and evaluated with uncertainty.Calculation and analysis are carried out.The calculated results show that the gauge method is satisfied with the large gear parameters measurement precision with grade 4.(3)The software of the measuring coordinate system is developed.According to the measuring principle,the accuracy analysis,and the planning of measuring path,the software of the standard gauge block method is developed by Visual C ++6.0.(4)The experiment of the standard gauge block method is conducted.Based on the C40 gear measuring center,coordinate system establishment precision influence of different position of the gauge block,different length of the gauge block,and inclination of workbench are obtained respectively.The experimental results show that the gauge block length is within 300 mm,R axis coordinate system measurement accuracy within1μm,T axis accuracy within 2.5μm.Under the same conditions,using the standard gauge block+ autocollimator optimized scheme show the experimental results,the accuracy of the R axis coordinate system is less than 1μm,and the accuracy of the T axis is less than 1μm.