scope:

A comprehensive model for the measurement, inspection, performance prediction and reverse engineering of ZK type of worm gearing is developed. The measurements and the best fit processes both for the worm thread and for the gear tooth flank are discussed in detail. A CMM measurement strategy free of tip compensation which applies to many types of tools and parts in the gear industry is proposed. A real case of ZK type of worm gearing with the parabolic profile modification on the hob is studied to illustrate the reverse engineering process.