Accuracy improvement method for double flank worm gear pair rolling tester

Abstract

To improve the measurement accuracy of the double flank worm gear pair rolling tester, the grating system is calibrated by laser interferometer and then compensation model using polynomial function is established, uncertainty budget is carried out based on the sensitivity test and error sources analysis, and some factors are adjusted to lower the measurement uncertainty. After compensation, the positioning error of worm gear moving slider, worm slider and worm gear measuring slider is reduced from 1.80 μm to 0.20 μm, 20.00 μm to 0.50 μm, and from 0.70 μm to 0.05 μm respectively. Related sensitivity coefficients for measurement results total radial composite deviation Fid, tooth-to-tooth radial composite deviation fid,andrunoutFr are within 0.01 to 0.04. According to GUM, three parts are considered in uncertainty evaluation including standard uncertainty of base unit, standard uncertainty of data acquisition & software system and standard uncertainty of measurement condition. After the optimization of the main error sources, the expanded uncertainty for measurement results Fid, fid,Fr is reduced from 5.4 μm, 4.6 μm and 2.5 μm to 2.6 μm, 2.1 μm and 1.5 μm respectively. The experimental results show that, the accuracy improvement method for double flank worm gear pair rolling tester can reduce measurement uncertainty, and the whole work can be a certain reference for the accuracy improvement of precision instruments.