轿车后轮轴承早期剥落失效特性与机理研究  

Investigation on unpredicted failure flaking of automobile rear-wheel bearings

作　　者：张雪萍[1] 姚振强[1] 俞亚波[1] 胡海[1] 王成焘[1] 

机构地区：[1]上海交通大学机械工程学院,上海200030

出　　处：《中国公路学报》2000年第2期112-115,共4页China Journal of Highway and Transport

摘　　要：研究了轿车后轮轴承的早期失效。通过对 2 0 0套失效轴承的统计分析发现 ,在轿车每个后轮的一对轴承中 ,早期失效大多发生在外列小轴承 ,主要失效形式为轴承内外圈滚道的等间距分布的严重条状剥落和随机分布的大端疲劳剥落。提出了基于轴向游隙关系的后轮轴承失效机理模型 :轿车两后轮轴承对的工作游隙的差异是导致两轮外侧小轴承出现早期失效的主要原因。当轿车转弯、侧倾行驶、或者两后轮路谱有较大的差异时 ,与后桥连为一体的两个后轮轴颈将相对车轮发生轴向窜动 ,使游隙相对较小一侧后轮的外列小轴承 ,承受了本应由另一侧内列大轴承承受的轴向载荷 ,加之因弯矩作用而产生的附加径向载荷 ,使外列小轴承发生早期失效 ,因此在轿车后轮轴承的设计、装配及维修中 ,应尽量控制两轮轴承对轴向游隙的差值。The unpredicted failure of automobile's rear wheel bearings is investigated in this paper.The statistical analysis from 200 pairs of failure bearings reveals that proportionally spaced grating flakes and stochastically distributing fatigue flake are two dominating failure forms,which occur primarily on the raceway of the smaller external one of the bearing pair.A failure mechanism model is presented through the analysis of rear axle structure,bearing clearance,and running dynamics of the automobile.It is pointed out that:the clearance difference between the two bearing pairs of the two rear wheels will inevitably result in unpredicted failure;the axial traversing trend,resulting from the disaccord between dynamic radical forces of the left and right wheels,will subject the smaller external bearing to extra axial load which is supposed to be undertaken by the larger internal bearing at the other side,resulting in proportionally spaced grating flakes and impressions on smaller bearing's raceway,and when automobile twists ahead or moves straightly on a road inclined laterally,the smaller external bearing at the side with smaller axial clearance will suffer from both extra axial load and extra radical load due to the action of axial load from the time through a offset of wheel radium,bringing about severe fatigue flaking on its raceway.It is suggested that the axial clearance difference between the two bearing pairs should be minimized during the design,assembly,and maintenance of the automobile rear wheel.

关 键 词：轿车 后轮轴承 早期失效 条状剥落 轮毂 

分 类 号：U463.343[机械工程—车辆工程]