Gear geometric control software : approach by entities

Abstract

To develop Net Shape parts by forging, process planing must take design, production, heat treatment and control difficulties into account the earliest it's possible. In this perspective, we propose to present an aspect of our work, made in collaboration with an industry, which deals with the dimensional control of the functionality of forged straight bevel gear for car differentials. To study the functionality of the gear, we have split it up into entities which could be looked from different views (designer, manufacturer, metallurgist, …). The metrologist is interested in the geometry of the entities. After the measurement on coordinate measuring machine, the development of a software enable us to obtain the standard deviations of gears by analysing the position defaults or the intrinsic defaults of all entities. This new approach enables to qualify the whole process planning. Then, the development reported in this paper deals with the eccentricity between the Net Shape teeth and the assembly surfaces manufactured before heat treatment.