冲击载荷对铁路轴箱轴承塑料保持架动态性能影响研究

摘要

铁路客车轴箱轴承除了承受来自于一系悬挂之上车体及构架的直接压力,还承受因为轨道不平顺轮对冲击传递而来的冲击作用,由于冲击而造成的保持架过梁断裂是轴承提前失效的主要因素之一.分析车轮扁疤对车系统产生的冲击并将其作为轴承动力学的边界条件输入,采用离散单元法建立柔性保持架,研究了冲击载荷对铁路轴箱轴承保持架动态性能、滚子与保持架之间作用力以及保持架应力分布的影响.研究结果表明:随着冲击加速度的增加,滚子与保持架之间碰撞作用力和频次显著增加,加速保持架的疲劳失效.通过对保持架过梁的强度分析可以判断,较大的轮轨冲击加速度会造成保持架过梁的直接断裂.%Besides supporting the direct heavy load above the primary suspension,railway axle box bearings also bear the impact loads passed from the wheel and rail interaction due to track irregularity.The cage bridge fracture because of impact loads is one of the main factors leading to the early invalidity of bearings.The influence of the impact from wheel flat on the vehicle system was analyzed and taken as the boundary condition in bearing dynamics analysis.The discrete element approach was used to model the elastic cage.The influences of impact loads on the axle bearing cage dynamic characteristics,the contact force between the roller and cage and the stress distribution in the cage were researched.The results show that the contact force and contact frequency between the roller and cage increase significantly with the increase of the impact acceleration,which will speed up the fatigue failure of the cage.It can be judged from the cage strength analysis that the external heavy impact acceleration from the wheel and rail interaction will lead to the instant fracture of cage bridges.