修形对直齿锥齿轮弹性流体动力润滑的影响

Effects of Profile Modification on Elastohydrodynamic Lubrication of Straight Bevel Gear

为解决直齿圆锥齿轮的端啮问题,通过对直齿圆锥齿轮进行齿廓修形,提高小端的油膜承载能力,使得载荷沿齿宽方向分布均匀。齿廓修形先采用二次抛物曲线,再改变主动轮和从动轮的齿顶修缘高度,确定修形参数后,建立直齿圆锥齿轮无限长线接触弹性流体动力润滑模型,压力和膜厚采用多重网格法求解,弹性变形采用多重网格积分法求解。齿顶修缘后啮入点的油膜压力比原来小,油膜厚度变大;二次抛物曲线修形后,啮入瞬时点和啮出瞬时点的油膜压力在赫兹接触区明显降低,赫兹接触区的油膜厚度明显增大,沿啮合线分布的最大油膜压力降低,最小油膜厚度增大,中心油膜压力降低,中心油膜厚度增大;修形参数的变化影响修形后的油膜压力和油膜厚度;修形改变了齿宽方向的载荷分布,直齿圆锥齿轮的小端和大端的载荷差距减少,齿面载荷由端部向齿宽中部转移。研究结果说明,齿廓修形可以改善齿轮的润滑状况,提高啮合过程的油膜压力,减少齿面的摩擦和磨损,同时也可以避免齿面胶合的产生。

In order to solve the spur bevel gear end meshing problem,through the straight tooth bevel gear profile modification,improve the small end of the oil film carrying capacity,making the distribution of load along the width of the tooth evenly.The second parabolic curve is adopted in tooth profile modification firstly,and then the height of the tooth edge trimming of the driving wheel and the driven wheel is changed.After determining the modification parameters,an elastohydrodynamic lubrication model is established for the straight line contact of the bevel gear with infinite line,the pressure and the film thickness are solved by the multigrid method,and the elastic deformation is solved by the multigrid integration method.The results show that the oil film pressure at the tooth point after trimming the edge is smaller than that of the original,and the oil film thickness becomes larger.After the second parabolic curve modification,the oil film pressure at the instantaneous point of engagement and instantaneous point of engagement is significantly reduced at the Hertz contact area.The oil film thickness in the Hertzian contact area increases significantly,the maximum oil film pressure on the grinding mesh distribution decreases,the minimum oil film thickness increases,the central oil film pressure decreases,and the central oil film thickness increases.Modification parameters affects the oil film pressure and oil film thickness after the modification,modification changes the load distribution in the direction of the tooth width,the load difference between the small end and the large end of the straight bevel conical gear is reduced,and the tooth surface load is transferred from the end to the middle of the tooth width.Tooth profile modification can improve the lubrication condition of the gears,increase the oil film pressure in the meshing process,reduce the friction and wear of the tooth surface,and at the same time avoid the occurrence of tooth surface glue.