Geometrical Specification Model for Gear - Expression, Metrology and Analysis

To ensure the gear precision, industries need a coherent model to express, to analyse and to check geometrical specifications. Most gear tolerance representations are directly driven by the convenience of dimensional metrology and not by the convenience of the set of activities of the tolerancing process. Therefore, to ensure the coherence of all tolerancing process activities, there is a necessity to develop a complete gear tolerance model which should: represent standard tolerance practices; be integrated in the Computer-Aided systems of design, manufacturing and metrology; be controlled by CMM; and support automated tolerance analysis. The proposed model extends capabilities of a vectorial dimensioning & tolerancing model in order to satisfy the four requirements. This model is based on GeoSpelling [1]. Its coherence is illustrated by two applications: gear tolerance analysis and gear tolerance verification by CMM.