Method and apparatus for inspection of gears

Abstract

Apparatus for manual inspection of gears. The apparatus is particularly useful for determination of helical angle deviation and taper in helical gears. The ear to be inspected is placed in a suitable holder, or on a smooth support surface. A selected master gear segment, manufactured to precise tolerances such that it would perfectly fit an inspected gear that has no error, is brought into meshing engagement with the inspected gear. The selected master gear segment is supported in a working position by a support structure in a manner that the selected master gear segment may be displaced about an axis with respect to a reference datum plane. Support is provided by a pivot pin protruding from the support structure, or alternately by a pivot pin protruding from the gear segment into the support structure. Displacement of the selected master gear is by way of rotation of the gear about the pivot pin, or about both the pin and a ball in the case of a two axis movement type unit which is used for measuring both helical angle deviation and taper. By utilizing a selected master gear segment of known length, the displacement of the measuring surface from the datum plane may be determined by way of a height gage. A suitably positioned dial test indicator is normally utilized to measure the height. The measuring surface further includes a surface of known width for those cases where taper is also measured.