Position Adjustment And Measurement Coordinate System Establishment For Sidemounted Gear Measuring Machine

Large gears are key transmission components of large equipment,widely used in ships,power generating units,mining machinery,aerospace and other fields,so as a means to ensure the quality of large gear manufacturing,its inspection technology is of great research value,and this paper focuses on the uncertainty problem of the establishment of the measurement coordinate system.The side-mounted gear measuring machine is expected to become an effective tool for precision measurement of large gears,and the most basic problem of using a side-mounted gear measuring machine to measure gears on the machine is how to correctly establish the measurement coordinate system to the workpiece coordinate system with the gear rotation center as the coordinate origin,and this paper investigates the uncertainty of establishing the coordinate system for side-mounted large gear measurement.Firstly,the uncertainty of the coordinate system of gear measurement established by laser tracker is investigated and its error sources are analyzed through actual measurement experiments.It is found that the uncertainty of large gear measurement coordinate system established directly by laser tracking instrument is large,and it is difficult to meet the requirements of large gear measurement accuracy.Then,a new measurement coordinate system establishment method for the on-machine measurement of large gears with a side-mounted gear measuring machine is proposed,in which the machine coordinate system and the workpiece coordinate system are leveled with PSD,and then the rotation center of the measured gear is searched for,and the measurement coordinate system is established with the rotation center as the coordinate origin.The key technology to establish the measurement coordinate system is how to find the position of large gear rotation center accurately.This paper proposes to use laser distance measurement technology to find the X-direction position of gear rotation center,which solves the problem that the side-mounted gear measuring machine cannot pass the large gear rotation center due to the short X-axis travel,and thus cannot establish the large gear measurement coordinate system accurately.According to the proposed new large gear rotation center detection principle,a large gear rotation center high-precision detection scheme and device are designed.The X-directional midpoint of the large gear is measured with a Leica laser rangefinder ?-base,and the Y-directional midpoint of the large gear is measured with a 2D PSD and a T-axis grating of the measuring machine to determine the position of the rotation center of the large gear.And by establishing the error model,the systematic error analysis of the rotation center detection scheme was carried out.The results show that for the measured gear of 500 mm diameter,when the installation angle deviation of ?-base in the XOZ plane is 1.5?,the deviation of the X-direction position of the rotation center is 1?m;when the installation angle deviation of the laser in the XOY plane is ? is1?,the deviation of the Y-direction position of the rotation center is 1.2?m,which satisfies the requirement of establishing the coordinate system for large gear measurement.