基于润滑特性仿真的燃油泵滑动轴承优化设计

The aim of this study was to increase the lifetime and solve the problem of sliding bearing failure of aero fuel gear pump under the limitation of low medium viscosity and self-cooling structure. An optimal design strategy of sliding bearing based on the distribution law of lubrication characteristics was proposed. 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. 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 were simulated based on CFD numerical simulation and finite difference method, and the lubrication characteristics were analyzed under different clearance ratio, eccentricity ratio and width diameter ratio. The characteristic curve of sliding bearing under different structural parameters was obtained to optimize the sliding bearing structure by adopting indirect optimization strategy of genetic algorithm. The simulation results show that the eccentricity and the width to diameter ratio of the optimized bearing can be 0.822 4 and 1.2, the oil film thickness was 2.7 μm, the average temperature was 36 degrees, which ensured that the bearing had a good lubricating performance and no friction contact between the bearing and the bushing. The capacity error between the experimental value and the calculated value of the optimized bearing was not more than 5%. The lubrication characteristic analysis method adopted had a high simulation accuracy and bearing had a better lubrication characteristics.