一种自冷却结构燃油泵滑动轴承润滑特性分析

为研究低介质黏度和自冷却结构限制下的航空燃油泵滑动轴承润滑特性分布规律，基于油膜动压润滑流动的Reynolds方程和等效黏度润滑流动模型，以绝热流动为假设简化滑动轴承内部流动的能量积分方程，构建一种联合Reynolds方程和绝热流动能量积分方程的燃油泵滑动轴承热流动润滑流动模型。采用CFD数值模拟和有限差分法相结合的混合仿真方法，分别对不同的间隙比、偏心率、宽径比条件下的滑动轴承的油膜压力、油膜厚度、油膜温度、端泄漏量、摩擦阻力等润滑特性进行了仿真分析。仿真结果表明：采用CFD计算滑动轴承径向载荷精度优于4.0%；保持偏心率不变，油膜承载力随着间隙比的增加而单调下降，油膜厚度随着间隙比的增高而增加；保持间隙比不变，油膜的承载力随着偏心率的增大也逐渐增大，油膜厚度随着偏心率的增高而下降，而油膜温度与油膜厚度成反比，且随着偏心率的升高，油膜温度的峰值越来越明显；当偏心率、间隙比一定时，可通过增加宽径比提高滑动轴承的油膜承载力。因此在滑动轴承的设计中，需综合考虑油膜承载力、端泄漏量、油膜厚度和温升间的相互制约因素，合理地优化间隙比、宽径比和偏心率以提高滑动轴承润滑性能。

Lubrication characteristics analysis of a type of self-cooling structure fuel pump sliding bearings

The aim of this paper was to study the lubrication characteristics of sliding bearings for aeroengine fuel gear pumps under low medium viscosity and self-cooling conditions. Based on the Reynolds equation for hydrodynamic lubrication of oil film and equivalent viscosity lubrication flow model, the energy equation of the internal flow was simplified by assuming the adiabatic flow of the gear pump sliding bearing, and the thermal flow lubrication mathematical model of fuel pump sliding bearing was established based on the combination of Reynolds equation and adiabatic flow energy integral equation. Then the lubrication characteristics of sliding bearings, including the oil film pressure, oil film thickness, film temperature, surface leakage, and friction, were simulated and analyzed based on CFD numerical simulation and finite difference method under different clearance ratios, eccentricity ratios and width diameter ratios. The simulation results show that the radial load calculation accuracy of sliding bearing is better than 4.0% by CFD method. The oil film pressure decreases monotonically with the increase of the clearance ratio, and the oil film thickness increases with the increase of the clearance ratio under the condition of constant eccentricity ratio. Under the condition of constant clearance ratio, with the increase of eccentricity ratio, the oil film pressure gradually increases and the oil film thickness decreases, while the oil film temperature is inversely proportional to the film thickness, and the peak value of temperature is more and more obvious. Also, the oil film pressure of the sliding bearing can be increased by increasing the width diameter ratio when the eccentricity ratio and clearance ratio are constant. Therefore, in order to improve the lubrication performance of sliding bearing, it is needed to design a reasonable clearance ratio, width diameter ratio and eccentricity ratio of sliding bearings by considering the factors of oil film pressure, leakage, thickness and temperature rise and the interaction among them.