重载下准双曲面齿轮传动界面润滑机理分析

Analysis on Lubrication Performance of Hypoid Gears at Heavy Loads

综合考虑了准双曲面齿轮传动接触几何、卷吸速度与椭圆主轴不重合、润滑剂流变特性等因素,建立了准双曲面齿轮传动界面润滑机理分析的统一数学模型,数值分析了重载下准双曲面齿轮传动一对啮合副从啮入到啮出过程中啮合点油膜、压力、闪温和von Mises应力的演变规律,探讨了小齿轮转速对传动界面润滑性能的影响。结果表明:从啮入到啮出过程中,啮合点的中心油膜厚度和最大von Mises应力呈现单调递减趋势,表面最大闪温则是先升高然后逐渐降低;转速对传动界面润滑状态的影响非常显著,随着转速的逐渐减小,啮合点中心油膜厚度也随之减小,由于工程中粗糙表面的存在,界面容易因滑动摩擦发生磨损;转速越高,啮合点的闪温也越高,此时齿面容易发生胶合失效,为了最大限度地避免齿面磨损和胶合,需要合理选择准双曲面齿轮的运行转速。

A unified lubrication model is established for hypoid gears considering the effects of contact geometry, the oblique angle between entrainment speed and principal axis of ellipse, as well as theological properties. The pressure, film thickness, flash temperature and yon Mises stress are obtained at different meshing points from beginning to the end of whole engagement process under heavy load conditions. Besides, the effect of speed on the lubrication performance is also studied. The results reveal that both the central film thickness and the max von Mises stress show a monotone decreasing tendency during the whole engagement process; the max flash temperature increases first and then gradually decreases; and the effect of rotational speed on the lubrication performance in contact surface is significant. The central film thickness decreases gradually with the decrease of rotational speed, leading to abrasion due to the sliding friction on rough surface. In addition, the higher the rotational speed is, the larger the flash temperature will be, which may lead to scuffing failure on the contact surface. Therefore, in order to avoid abrasion and scuffing failure as much as possible, it is necessary to properly select the rotational speed of hypoid gears.