A method for measuring concentricity errors of a gear wheel

摘要

A method of measuring errors in the rotational truth of gear teeth of a gear by means of a measuring device having a feeler guide which is pivotable about a pivot axis parallel to the gear axis, the feeler guide guiding a feeler which is prebiased in the direction of the gear and cyclically engages into the gear teeth as the gear rotates. The feeler together with the feeler guide is pivotable about its pivot axis and can be displaced back in relation to the feeler guide. An electronic circuit determines the largest degree of rearward displacement of the feeler during each measuring cycle in that it stores signals delivered by the feeler and compares such stored signals with one another. During each measuring cycle there is formed from a number of signals delivered by the feeler as well as from a number of subsequently delivered signals a respective mean value. Both mean values are compared with one another, the larger of such mean values, to the extent that it constitutes the mean value of the later signals is stored, and this procedure is repeated for such length of time until there is present a mean value which is smaller than the directly previously formed mean value, whereupon such previously formed mean value is delivered as the maximum value of the related measuring cycle.