Tolerance analysis of involute spur gear from the perspective of design

Abstract

The existing gears’ tolerance standards are formulated from the point of view of manufacturing and measurement. Tolerance categories are numerous. What is more, they have no correlation with each other. Tolerance analysis and optimization of gear and gear set are difficult. Module, pressure angle and center distance are the most important parameters for gears. Their variations directly affect the transmission precision of gears. Through careful research of the influence of deviations of module and pressure angle, a novel method of gear tolerance analysis is proposed in this paper from the perspective of design. For a single gear, tolerance specification and analysis only pay attention to these two tolerances. The influence of fluctuation of center distance for a gear set is also studied. Meanwhile, the calculation method of sensitivities and percent contributions about related parameters is introduced, which provides the basis for tolerance optimization. At last, a simple case is studied, which demonstrates the validity and novelty of the present work.