Measurement of Three-Dimensional Curved Surface of Machine Part Using Holographic Interferometry. 2nd Report. Tooth Flank Form Deviation of Spur Gear.

Abstract

Tooth flank form deviation of spur gears is measured by laser holographic interferometry. In order to get the diffracted ray from the objective tooth flank to be measured in definite directivity, a laser beam is irradiated with large incident angle to the surface which has a considerably rough surface finish. The conversion of the coordinates of the image figure of the objective surface, i. e. the gear tooth flank, on the CRT to the coordinate system of the gear is worked out by the fitting of contour form of simulated and observed images on the CRT. By using this method, image patterns of the interference fringe of some tooth flanks with various kinds of form deviation were measured. The algorithm of transformation from these fringe patterns to tooth flank form deviation by converting brightness of interference fringe images on the CRT to the amplitude of form deviation defined on the plane of action of the gear via phase difference of the light beam by a fringe scanning device is shown. The measured tooth flank form deviation is compared with the results of a conventional measuring method of tooth form using a contacting stylus.