Design of a helical gear set with adequate linear tip-relief leading to improved static and dynamic characteristics

This study aims to improve the static and dynamic characteristics of a helical gear pair by optimizing the parameters of linear tip-relief. The static analysis intends to reduce the maximum contact stress to extend the service life of the gear pair, while the dynamic analysis attempts to reduce the dynamic transmission error (DTE). First, mathematical models of a helical gear pair generated by rack-cutters with linear tip-relief were developed based on the theory of gearing. Tooth contact analysis enabled us to estimate static transmission error and contact pattern of the gear pair under various assembly errors. Additionally, the contact stress contour and mesh stiffness were calculated through loaded tooth contact analysis by using finite element analysis. A dynamic model of the helical gear pair was also developed to simulate the dynamic characteristics under various rotational speeds, including DTE and vibration energy. Finally, the simulation results revealed that the high contact stress, DTE, and vibration energy of the original helical gear set were successfully reduced by the improved linear tip-relief parameters.