汽车变速器表面涂层齿轮疲劳性能试验与接触强度研究

Study on the Fatigue Performance Test and Contact Strength of Automatic Transmission Gear with Coating

在齿面制备减摩涂层可以有效地改善接触条件,提高齿轮疲劳寿命。文中主要研究减摩涂层对齿轮接触强度的影响规律。首先,在SRV标准试件表面制备涂层,通过摩擦磨损试验获得涂层试件间摩擦因数变化曲线;其次,对无涂层和有涂层的汽车自动变速器齿轮进行疲劳耐久试验,通过测量得到试验后齿轮的表面形貌特征;最后,根据齿轮非线性弹塑性接触理论,建立粗糙表面的齿轮接触强度分析模型,得出减摩涂层在提高齿轮接触疲劳强度中的作用。研究结果表明,磷酸锰转化涂层通过降低齿轮接触应力从而可以提高齿轮的疲劳耐久寿命;齿轮最大接触应力随粗糙度呈现先降低后升高的趋势。为涂层齿轮强度设计提供理论指导。

The contact condition of gear surface can be improved by preparing the antifriction coating,and then strengthen the fatigue life of gear. The influence of antifriction coating on contact strength of gear is studied. Firstly,the antifriction coating is prepared on SRV standard specimen surface,the friction coefficients of coated specimens are obtained through friction-wear test. Then,the fatigue endurance tests are carried out for uncoated and coated automatic transmission gear in automotive transmission,the surface morphology characteristics of the gear are obtained by measuring. Lastly,an analysis model of contact strength on rough surface is established based on nonlinear elastic-plastic contact theory of gear. The effect of antifriction coating on improving the contact fatigue strength of gear is obtained. The results show that the manganese phosphate coating can improve the fatigue endurance life of gears by reducing the contact stress,the maximum contact stress of gear decreases first and then increases with the roughness,which provides theoretical guidance for strength designing of the coated gears.