Research On The Measurement And Analysis Method Of The Geometric Error Of Shaft Gear Under The Condition Of Inconsistent Datum

Shaft gear is a typical shaft part and an important basic part in mechanical system.It is widely used in automotive,aviation,shipping,machine tool and other industrial fields.Their geometric accuracy is of great significance to the comprehensive performance of the entire system.Measurement is an important part of controlling the geometric accuracy of shaft gear.In the actual shaft gear processing and manufacturing,it often appears that the positioning datum of the workpiece during measurement is inconsistent with the working datum when the workpiece assembled into the system is motioning,and because the geometric error evaluated by the working datum as the measurement datum is more in line with the actual situation and has higher accuracy.As a result,the inconsistency of the measurement positioning datum and the working datum directly reduces the accuracy of the measurement results,so as to increase the possibility of misjudgment of product quality.Therefore,research on the measurement and analysis method of geometric error of shaft gear under the condition of inconsistent datum is of great significance to ensure the accuracy of gear manufacturing and measurement results.In order to propose a measurement method that can reduce the measurement error caused by the inconsistent datum.This paper analyzes in detail the influence of the inconsistent datum on the geometric error measurement of shaft gear.Through the analysis of the reasons leading to the inconsistent datum,an error compensation method based on coordinate transformation is proposed,and a mathematical model of error compensation is obtained.In view of the fact that the character line measurement method used in the geometric error of the gear will cause the measurement trajectory to deviate due to the inconsistent reference,which will cause the measurement error,a point-by-point local error compensation method is proposed.The main research contents of this paper are as follows:(1)Analyze the influence of the inconsistency between the measurement positioning datum and the working datum on the main four single errors of the gear.Mainly starting from the gear single error concept and evaluation method,the error items affected by the inconsistent datum are analyzed,and the correctness of the analysis results is verified by comparative experiments.(2)By analyzing the reasons for the inconsistency of the measurement positioning datum and the working datum,the measurement process to realize error compensation is proposed,and the specific realization process is proposed,including: the measurement plan,the fitting method of the ideal circle of the cross section,the fitting of the working datum axis,etc.,and finally get mathematical model of error compensation.(3)Aiming at the deviation of gear geometric error measurement trajectory caused by the inconsistent datum,resulting in measurement error,a feasible error compensation method for each error and measurement point was proposed by analyzing the error items that would lead to the deviation of gear geometric error measurement trajectory due to the inconsistent datum.Through the above theoretical research and the corresponding experimental verification,this article draws a systematic measurement and analysis method of the geometric error of the shaft gear under the condition that the measurement positioning datum and the working datum are inconsistent.