Optimization Framework of Reduction Gear for Construction Vehicle based on Tooth Profile Crowning

The need for optimized reduction gear is crucial for the development of high-performance construction vehicles. Previous research endeavored to optimize gearbox efficiency through the optimization of key parameters, including the number of teeth, profile shift coefficient, and center distance. Nonetheless, a significant portion of efficiency decrement stems from the phenomenon of slip occurring between the engaging teeth during meshing. In the present study, the tooth profile of an involute gear was subject to modification using a newly proposed profile crowning technique. The proposed involute-like profile crowning enhances the performance of the gear in terms of average efficiency, even under heavy loads causing deformation. Through transient finite element analysis, the optimal magnitude of this modification was determined. Initially, the theoretical determination of the reference gear train efficiency yielded a value of 98.37%, a result that was subsequently validated in the analysis assuming a rigid body. However, in practical scenarios, the presence of minor deformations at the tooth interface adversely affects the efficiency, resulting in a reduced value of 98.18% and 97.99% as indicated by the analysis. Assuming a constant coefficient of friction, the tooth modification improved the efficiency to 98.48%, 98.27% and 98.09% for rigid and flexible bodies respectively. Further investigation could be made from the analysis of the loss at the contacting surfaces of the gear teeth.