Measuring Sensors Calibration in Worm Gear Rolling Testers

Abstract

The ISO standard regulating gear-rolling measurement does not specify in detail the calibration and verification procedures for this type of equipment. This may be one of the reasons for the lack of reproducibility in these rolling tests. The uncertainty budget method, which is the most appropriate way to know the accuracy of this dynamic measurement, shows that the measuring sensors’ accuracy is only a part of the total measurement process uncertainty. In this work, a new calibration and verification procedure for a worm gear rolling tester is presented, based on machine tool, coordinate measuring machine and gear measuring instruments’ calibration techniques. After compensating numerically for the measuring instruments, it has been evaluated how the error components of each movement affect the meshing point, a fundamental factor to ensure a good gear transmission. The study shows that there are unintentional position variations, not detected by the measuring sensors, that have to be identified and quantified in the calibration for their later inclusion in the uncertainty budget. In this way, the measurement uncertainty could be reduced, and thus improve the reproducibility of these testers, as a preliminary stage to the development of optimized rolling measurement equipment to solve current limitations.

Characterization and parameters sensitivity analysis of worm gear rolling measurement

“…Therefore, a complete study of the characterisation of the rolling tests, as well as of the verification equipment itself, enables to identify the main terms of the measurement uncertainty and to calculate the sensitivity coefficients that quantify the influence of the main sources of error on the budget. The data obtained together with the data from the calibration and evaluation process of the equipment [18] can contribute to the proper estimation of the measurement uncertainty of these rolling testers. This work presents an experimental characterization procedure of the behaviour of a gear rolling test machine and single and double-flank rolling tests for worm gears.…”