基于应力释放提高齿轮弯曲强度方法的研究

Research of Improving Gear Bending Strength based on Stress Relieving

齿轮齿根圆角部位的应力集中是影响齿轮弯曲疲劳的重要因素,为了提高齿轮的弯曲疲劳强度,在齿面开应力释放圆孔使齿根应力重新分布来减小齿根最大弯曲拉应力。采用二维有限元计算圆孔的半径及最佳位置,通过三维有限元模型进行验证及接触应力计算,并进行弯曲疲劳极限分析。结果表明:对于选定参数的齿轮,齿面开圆孔可以使齿根应力重新分布来减小齿根最大弯曲拉应力,大大提高齿轮的弯曲疲劳寿命并减小齿轮质量;但应力的减小与开孔的位置及圆孔的大小有很大关系,存在最佳的圆孔大小和圆孔位置;齿轮参数不同也会引起最佳圆孔位置和大小的改变,并且齿根应力的微量减少都会使弯曲疲劳寿命大幅度提高。

Abstract Stress concentration of the gear tooth root fillet is an important factor to affect the ben- ding fatigue strength of the gear. In order to improve the bending fatigue strength, the stress relief hole in the tooth surface is established to make root stress redistributing to reduce root bending tensile stress. The two--dimensional finite element is used to calculate the best radius and location of the cir- cular hole. The three--dimensional finite element model is established to validate the result and to cal- culate contact stress, and the bending fatigue limit is also analyzed. The results show that, for select- ed parameters gear, tooth surface with hole can make the tooth root stress redistributing to reduce tooth root bending tensile stress, the bending fatigue life of the gear is greatly improved and the weight of the gear is reduced. The reduction of the stress has a great relationship with the location and size of the hole and there is a best size and position. Different gear parameters can also cause the hole best location and size changed, and the tooth root stress decreases a little can greatly improve the ben- ding fatigue life a lot.