Worm gear mother machine key error term identification method

Abstract

The invention discloses a worm gear mother machine key error term identification method, which comprises the following steps of 1, analyzing geometric errors of motion shafts of a worm gear mother machine, and establishing a position error model of a worm gear hob-worm gear workpiece based on a worm gear mother machine kinematic chain, an actual pose transformation matrix Twt and an ideal pose transformation matrix Twti of the worm gear hob relative to the worm gear workpiece being obtained, so that a machining error model of the worm gear machine is obtained; 2, regarding the machining error model of the worm gear machine as a multi-input multi-output nonlinear system, and analyzing the pose error model by using the global sensitivity of a polynomial chaos expansion method, 3, the single-effect sensitive index estimator and the full-effect sensitive index estimator being used for solving to obtain a sensitive index corresponding to each geometric error, wherein the larger the sensitive index is, the more critical the geometric error is, and the larger the sensitive index is, the more critical the geometric error is. And the influence on the machining precision of the worm gear machine is greater.

Description

technical field [0001] The invention belongs to the technical field of mechanical error analysis, in particular to a method for identifying key error items of a worm gear machine. Background technique [0002] Worm gear is one of the most common basic parts in mechanical transmission, and its forming accuracy directly affects transmission accuracy, stability and uniformity of load. The machining accuracy of worm gear depends on the accuracy of the worm gear parent machine, and is affected by multi-source errors, including machine tool geometric error, thermal error, force error, servo control error, etc. Among them, the geometric error caused by manufacturing and installation of machine tool parts is the most important error source of worm gear machining error, which belongs to quasi-static error and does not change in a short period of time, so it is easy to be eliminated by control. Since the worm gear machine belongs to multi-axis CNC machine tools, not only the number o...

AI Technical Summary

Problems solved by technology

However, this type of method lacks the consideration of the probability distribution and random characteristics of parameters, the analysis results only contain local gradient information, and the sensitivity analysis results to processing errors are not completely accurate

In addition, as a special processing machine tool for worm gears, the worm gear machine belongs to the continuous generating and hobbing process, and currently lacks a machining error model for it under the coupling effect of multiple geometric error elements

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