倾斜式双滚柱包络环面蜗杆传动弹流润滑分析

Analysis of Elastohydrodynamic Lubrication of Inclined Double-Roller Enveloping Hourglass Worm Drive

为了研究倾斜式双滚柱包络环面蜗杆传动在啮合过程中考虑粗糙度时的润滑特性,根据弹性流体动力润滑理论和牛顿流体弹流润滑模型,建立了倾斜式双滚柱包络环面蜗杆传动的弹流润滑简化模型和线接触弹流润滑数学模型。考虑共轭齿面粗糙峰和粗糙谷对弹流润滑的影响,采用牛顿迭代法和牛顿-拉夫逊法对该传动副进行了数值求解,分别得出粗糙峰和粗糙谷在不同粗糙度幅值时的油膜厚度和油膜压力曲线,并分析了一个共轭齿对从啮入到啮出不同啮合时刻的油膜厚度和油膜压力。最后,分析了滚柱半径、喉径系数、滚柱偏距对弹流润滑特性的影响。结果表明:粗糙度的存在对传动副的润滑是不利的,粗糙度幅值越大,越不利于传动副的润滑;在第3个齿开始啮入的时刻,是传动副润滑的最危险区;要保持该传动副具有良好的润滑性能,滚柱半径、滚柱偏距不宜过大,喉径系数不宜过小。

To study the lubrication property with consideration of the conjugating surface roughness in transmission process of inclined double-roller enveloping hourglass worm drive,a simplified model of elastohydrodynamic lubrication(EHL)and a line contact mathematical model are established with Newtonian fluid EHL model based on the meshing theory and EHL theory.Considering the influences of rough peaks and rough grooves on conjugating surface on the EHL of this worm drive,the oil film pressure and thickness curves are obtained by using Newton iteration and Newton-Raphson method at different roughness amplitudes,and the oil film pressure and thickness of one conjugating tooth-pair are analyzed at different meshing points from meshing in to meshing out.At last,the influences of roller radius,orifice coefficient and offset distance on the EHL characteristics of this worm drive are analyzed.The results show that the conjugating surface roughness has adverse effect on the lubrication property of this worm drive.At the moment when the third tooth begins to mesh in,it is the most dangerous area for the EHL of this worm drive.The roller radius and offset distance should not be too big,and the orifice coefficient should not be too small,for effectively improving the lubrication property of this worm drive.