宽内圈关节轴承径向极限承载破裂失效原因
2018-01-13林志埙
摘要: 对端部有台阶(宽内圈)和无台阶(窄内圈)关节轴承施加相同的径向极限载荷时,寬内圈端部台阶发生破裂失效现象,而窄内圈却完好无损。为分析台阶破裂原因,采用有限元方法对2种内圈结构进行径向极限承载分析,从位移、等效应力和主应力等3个方面分别描述两者之间的区别。结果表明:宽内圈端部台阶的局部应力集中部位最大等效应力值较小,但是该部位的变形量较大;第一主应力呈拉应力状态且其数值已超过材料的屈服强度,是造成宽内圈开裂的主要原因。
关键词: 宽内圈; 径向静载; 破裂失效; 等效应力; 主应力; 变形; 轴承
中图分类号: V229.2文献标志码: B
Crack failure reasons in extended inner ring of spherical
plain bearings under radial limit loading
LIN Zhixun
(Fujian Longxi Bearing(Group) Co., Ltd., Zhangzhou 363000, Fujian, China;
Fujian Provincial Key Laboratory of Spherical Bearing, Zhangzhou 363000, Fujian, China)
Abstract: When the same radial limit loading is applied to the extended inner ring of spherical plain bearings with step at the end and the narrow one without step, crack failure occurs on the extended inner ring with step at the end, while the narrow one remains intact. In order to analyze the reasons for the crack of step, the finite element method analysis is carried out on the condition that the two kinds of inner ring structure are performed under the radial limit loading, and the differences between them are described in three aspects including displacement, equivalent stress, and principal stress. The results indicate that there is a smaller maximum equivalent stress at the local stress concentration place of the extended inner ring with step at the end, but there is a larger deformation at the same place. The major principal stress acts as tensile stress and its value exceeds the yield strength of the material, which is the main reason for the crack on the extended ring.
Key words: extended inner ring; radial static load; crack failure; equivalent stress; principal stress; deformation; bearing
收稿日期: 2017[KG*9〗03[KG*9〗17修回日期: 2017[KG*9〗05[KG*9〗02
基金项目: 国家科技支撑计划(2014BAF08B03)
作者简介: 林志埙(1982—),男,汉族,福建漳平人,工程师,研究方向为关节轴承的结构设计、强度计算、动力学分析,
(Email)15892012278@163.com0引言
自润滑关节轴承由内圈、外圈和自润滑衬垫组成,可承受较大载荷,有旋转、摆动、调心等功能,被广泛用于建筑、机械、起重、车辆、武器、航空航天等领域。[14]宽内圈自润滑关节轴承结构见图1。与常见的轴承内圈相比,此类轴承内圈带有凸台结构,可以起到调节轴承安装轴向跨距、增大结构摆动角度的作用,然而该凸台的内孔结构形状设计对轴承的径向极限承载能力有一定的影响。
1轴承径向承载试验
根据AS81820D标准[5]对轴承进行径向极限承载试验时,往往会遇到轴承破裂失效的问题[67],即试验施加的载荷尚未达到理论计算的极限载荷值,内圈端部外倒角便出现破裂现象,而且裂纹沿着轴向从外倒角向球面方向延伸。……
