层流紊流共存时径向滑动轴承热流体润滑性能分析

Analysis of Lubrication Performance of Hot Fluid of Journal Bearing under the Coexistence State of Fluid with Laminar Flow and Turbulence

研究了无限宽动压径向滑动轴承油膜中层流、紊流2种流态共存和热效应对轴承特性的影响.在考虑油膜中同时存在层、紊流2种流态的条件下,对雷诺方程、能量方程和黏温方程联立求解,得到油膜压力分布、温度分布、黏度分布、承载力、摩擦力等特性参数,并将某工况下混合流态时油膜特性结果与单一层流流态时的结果进行比较.结果表明,在绝热条件下,与单一层流流态相比,混合流态下油膜承载力、摩擦力较大,温升较高,黏度变化较大;热效应使轴承承载力明显下降.

In this paper, the characteristics of an infinitely wide journal bearing are investigated theoretically. In the bearing the laminar flow and turbulence, so-called coexistence state, are assumed to be existed simulta- neously in the oil film. And the thermal effect of lubrication oil is also considered. Under previous assump- tions, the coupling governing equations of bearing such as Reynolds equation, energy equation and tempera- ture-viscosity equation are solved together. Then we obtain the solutions of pressure, temperature, viscosity, friction and carrying-capacity fields. After we compared these solutions with those under the pure laminar flow state, some meaningful conclusions are given as follows. If adiabatic condition is satisfied in the bearing, com- pared to pure laminar flow state, bigger load-carrying capacity and friction, larger changing of oil viscosity and higher temperature will be found under coexistence state. Meanwhile, the load-carrying capacity of bearing significantly decreases when thermal effect is taken into account.