履带车辆高速行星轮滑动轴承混合润滑特性的研究

A Study on the Mixed Lubrication Characteristics of Journal Bearing for High-speed Planet Gears in Tracked Vehicles

针对某履带车辆行星变速机构中的行星轮轴承,探索其在高速工况下采用滑动支承的可行性。选择了聚四氟乙烯(PTFE)复合材料固体润滑轴承。基于平均流量模型和粗糙峰接触理论,研究了轴承的粗糙度、进油温度和相对间隙对其润滑性能的影响。结果表明:所选轴承的材料满足高速行星机构使用要求;选择合适的间隙和表面粗糙度,可同时实现低速时的混合润滑和高转速下的流体动压润滑;分析建议,设计相对间隙不应小于0.0015,表面粗糙度不大于0.8μm;并应加强控制,降低进油温度。

In this paper,the feasibility is explored of using journal bearing as the sliding support of the planet gears of planetary transmission in tracked vehicles under high speed condition.A solid lubrication bearing with polytetrafluoroethylene composite is selected.Based on the average flow model and the asperity contact theory,the effects of surface roughness,inflow oil temperature and relative clearance of bearing on its lubrication performance are analyzed.The results show that the bearing material selected meets the operation requirements of high-speed planetary mechanism.With proper clearance and surface roughness selected,both the mixed lubrication at low speed and the hydrodynamic lubrication at high speed can be realized.It is recommended by analyses that the surface roughness should not exceed 0.8μm and the relative clearance should not be smaller than 0.0015 in design,and the temperature of inflow oil should be controlled to a level as low as possible for good performance.