Gear Geometry Inspection Based on 3D Optical Scanning: Worm Wheel Case Study

Optical measurement methods provide fast data acquisition and the ability to evaluate the entire geometry of a scanned component. Capability of a three-dimensional optical scanning for a gear geometry inspection is presented and discussed. Due to its complex geometry and susceptibility to operating problems as a result of inaccurate manufacturing parameters, the inspection is conducted on a worm wheel. Geometrical accuracy of a scanned worm wheel model is evaluated with respect to the referent CAD model. The inspection is carried in accordance with DIN 3974 standard. Pitch deviation, profile deviation, runout deviation, and transmission errors are monitored. Transmission error numerical analysis is carried out. Scanned data is used to generate worm wheel surface model which is mated with the referent worm CAD model. Influence of various mesh sizes is investigated. Additional manufacturing errors which can significantly influence worm wheel operation are pointed out. The proposed method poses an alternative to conventional gear inspection methods which rely on inspection via coordinate measuring machines or specialized gear measuring instruments.