Papers by Author: Jun Shen

Abstract: A variable-grain strategy is proposed to solve the complicated problem of optimization design on high-speed transmission helical gears with multiple objectives and restrictions. Based on the theory of gear meshing noise and the superiority criteria, a multi-objective evaluation index system is brought forward which gives consideration to the increase of the contact ratio and the decrease of the noise generated by the slide ratio of the tooth flank meshing and the mutation of friction torque, and then the variable-grain multi-objective optimization models of high-speed helical gears are established. The coarse-grained model is utilized in the early design to efficiently determine the direction to the optimal solution. Then the grain is refined and the fine-grained model can be utilized to acquire the optimal result.

Abstract: For early failure problems, which are broken teeth of the first transmission driving gear in the test, this paper studies the problem in the failure mechanisms such as chemical composition analysis, fracture surface analysis as well as the metallographic structure morphology inspection analysis of failure gear. The results show that the main reasons causing abnormal fracture of the failure gear are the insufficient root shot peening strengthening, the small fillet of the spline groove and the inadequate rim thickness of the rim. This paper uses the finite element method to analyse the contact stress of failure gear and puts forward an improving design method.

Abstract: In order to meet high-volume, low-cost reducer and ensuring quality in the production of reducer, a new design method is necessary. This paper applies the design method of ‘modular’ in high-volume reducer production, preferred numbers and mechanical optimization design thought, then based on access database and VB programming software research modular design process of the volume reducer. Higher degree basic modular parameters of volume reducer are obtained.

Abstract: In view of the characteristics of the low-noise and high-strength of auto gears, this paper proposes a new method of optimization of fine-pitch tooth profile. Based on the constant gear-pair parameter values of transmission ratio, modulus, pressure angle, the method takes the optimal contact ratio as design object, sets up the constraint conditions such as noise limit index, non-interference, non-undercutting, and non-sharpened in the tip, and optimizes the addendum coefficient and coefficient so as to increase the contact ratio. In addition, this paper makes a finite element strength analysis on the design result, and the result shows that the new method can not only reduces noise but also improves gear strength of fine-pitch gear.