试样球径变化对载荷偏角的影响分析

Analysis of Load Angle Caused by Test Ball Diameter Change

在三点接触纯滚动轴承球疲劳试验机的基础上,分析了试样球径变化引起的加载机构对试样球载荷偏角的变化,进而影响试样球三点接触应力的相对误差。通过几何解析法,推导出载荷偏角与试验机本身几何参数之间的函数关系,举例说明了在不同设计球径和加载机构支点偏距时载荷偏角随测试球径的变化关系。研究表明,实际测试球直径在9～15mm之间,试验机设计半径(试样球)取6mm,加载机构支点偏距取0,载荷偏角变化范围小于0.106°时,如果载荷偏角变化许可范围增大,则相应的测试球径范围也将增大。

This paper proposed the relationship between the magnitude of load angle and the test ball diameter by geometric analytical method,based on the accelerated pure rolling contact fatigue test rig with three contact points for the life test of bearing ball.The results of application examples under the condition of different design diameters and offset distances of the loading mechanism pivot point show the load angle can be lowed down less than 0.106° when the design radius（test ball） is 6mm and the offset distance is 0,and the test ball diameters range from 9mm to 15mm.The larger the load angle magnitude is allowed to be,the wider the span of the test ball diameter can be.