轿车轮毂轴承实际工况下的脂润滑因基础黏度大、非牛顿特性强烈、当量接触曲率半径小,其弹性流体动力润滑计算有很大困难.文中在推导脂润滑弹流润滑计算基本方程的基础上,对方程进行了无量纲化和差分求解,求得轮毂轴承脂润滑弹流润滑的数值解,得到了润滑膜的压力分布和膜厚形状.结果表明:轮毂轴承脂润滑弹流润滑膜具有与油润滑类似的二次压力峰和出口膜厚颈缩现象;较小的载荷、较高的速度或较大的流变指数会形成较厚的润滑膜,相应的二次压力峰也更加明显;滚珠与滚道间的润滑实际处于弹流润滑和边界润滑交替变换的状态.

Due to the high initial viscosity,obvious non-Newtonian property and small equivalent radius in the grease lubrication of automotive wheel hub bearing under actual working conditions,great difficulties arise in the corresponding elastohydrodynamic lubrication (EHL)calculation.In order to solve this problem,basic grease lu-brication equations are derived,non-dimensionalized and difference-solved sequentially.After that,the numerical solutions of EHL of greased and lubricated wheel hub bearing,such as the pressure distribution and the thickness shape of lubrication film,are obtained.The results show that (1 )in greased and lubricated wheel hub bearings, there exist a second pressure peak and thickness necking similar to those under oil lubricated condition;(2)light load,high velocity and large rheological exponent all help to form thicker lubrication film with a more obvious se-cond pressure peak;and (3 )the lubrication between the rolling ball and the rolling cave is actually in an alte

采用多重网格法对几种常见载液的磁流体润滑滑动轴承进行了等温弹流润滑分析。在等温弹流润滑中,在保证其他条件不变的前提下,粘度是影响弹流润滑性能的主要因素。数值分析结果表明,随着粘度的增大接触区润滑膜的厚度逐渐变大,并且只有在一定的范围内,油膜才会呈现出明显的劲缩现象,这也是弹流润滑的最主要特征。超出一定范围之后,随着粘度的继续增大,油膜的劲缩现象减弱,直至消失。磁流体粘度对润滑膜膜厚的影响程度要明显大于对压力的影响程度,在润滑膜的入口区随着粘度的增大压力增大,压力峰则随着粘度的增大而减小,润滑膜的膜厚和最小膜厚则是随着粘度的增加不断增加。

The isothermal elstohydyodynamic lubrication(EHL) of ferrofluid bearing with different carriers was carried out by multi-grid method. If the other conditions remain unchanged, viscosity is the main influence factor in isothermal EHL. The results show that the film thickness on contact surface increase with increasing viscosity, and in a certain range, film shrink appears, which is the most obvious character of EHL. Beyond the certain range, the viscosity increase continuely, the phenomenon of film shrinking becomes less obvious and until it disappears. The influence of viscosity on film thickness is greater than on pressure. The pressure in the film entrance increase and the pressure peak decreases with increasing viscosity. The film thickness and the minimum film thickness increase with increasing viscosity.

在经典的弹性流体动力润滑理论分析中,油膜压力的计算要满足载荷平衡条件,而这一条件并不适用于发生在限制空间中的弹流润滑,当弹流润滑发生在限制间隙中,油膜的承载力会随工作参数的变化而变化。对限制间隙条件下等温线接触弹流润滑问题进行数值分析,研究油膜厚度及压力的变化规律。结果表明:在限制间隙等温线接触弹流润滑条件下,油膜厚度及压力随速度参数以及材料参数的增加而增加,而限制间隙增加时,膜厚增加,压力减小。根据数值分析结果,拟合出限制间隙条件下的膜厚计算公式,该公式有较小的计算误差。

In classical theoretical analyses of EHL(elastohydrodynamic lubrication),the calculated film pressure always fulfills the condition of loading balance,while this procedure cannot be applied to EHL in confined gaps.When EHL occurs in a confined gap,the load capacity will change with working parameters.Full numerical analysis was carried out for line-contact isothermal EHL with confined gaps,and variations of film thickness and pressure were discussed.It is found that with the increase of entrainment speeds and material parameters,the film thickness and pressure are increased.With the increase of gap parameter,the film thickness is increased,but pressure is decreased.From the numerical results,the film thickness equations were derived,and their calculation results have small errors with the simulation results.

考虑到进行艉轴承水膜厚度与压力计算时须考虑内衬材料的弹性变形,以提高艉轴承弹性流体动压计算精度,应用有限元法方法求得艉轴承内衬的弹性变形,结合雷诺方程求得计入弹性变形后的艉轴承水膜厚度与压力分布,并与流体动压润滑进行对比。结果表明,水润滑艉轴承弹流润滑计算得到的水膜压力减小,水膜厚度增大;艉轴是否倾斜对弹流动压润滑计算结果有明显影响。在相同工况下,随着艉轴倾斜率的增大,弹流润滑最大水膜压力上升,最小水膜厚度减小。

In order to improve the calculate accuracy of elastic hydrodynamic , it is necessary to consider the deformation of the lining.Both pressure and thickness distributions of water film which contrasts with the hydrodynamic lubrication were presen -ted by the Reynolds equation , and combining with the elastic deformation of the stern bearing by FEM .The result showed that the stern bearing water film pressure of elastic hydrodynamic lubrication is lower than that of hydrodynamic lubrication , while the wa-ter film thickness is larger .The slope of the stern shaft has significantly effect on the lubrication performances of stern bearing .In the same conditions , with the increasing of the slope , the maximum water film pressure of the elastic hydrodynamic lubrication ri-ses, while the minimum water film thickness decreases .

针对联合收割机齿轮副高速重载状态下润滑条件破坏失效问题，通过使用弹流润滑理论，结合实际齿轮啮合条件建立齿轮副模型，研究齿轮副中润滑油膜特性变化规律。分析结果表明：在相平面图中速度最大值和最小值处，系统的加速度发生了变化；由于润滑弹流之间存在相互作用，在稳态条件下总载荷近似均匀分担于所有的接触表面上，但在接触力峰值的部分（齿轮啮合和退出状态）不同接触面的接触力存在不同。

To the lubrication failure issue for combine harvester machine gear pair under high-speed heavy-duty statue, this paper established the model of gear pair and studied on the change law of its characteristics based on the elastic hydrodynamic lubrication theory, considering the actual conditions of meshing gears. The results showed that acceleration system changed at the maximum and minimum velocity in the phase plane, due to the interaction between the EHL lubrication, the total load approximately evenly shared on all contact surfaces under steady-state conditions, but there was a difference between contact forces of different contact surfaces in some contact force peaks (gear and exit status).