V形兜孔圆柱滚子轴承的高速动态性能

High-speed dynamic performance of cylindrical roller bearing with V-shape pocket

保持架打滑和动态不稳定是航空发动机主轴圆柱滚子轴承面临的难题,为此提出一种V形兜孔圆柱滚子轴承,并对其保持架打滑及稳定性展开研究。运用Hertz接触、弹流和流体润滑及牛顿-欧拉动力学理论,建立径向刚性加载下轴承的动力学模型,在此基础上,利用变步距龙格库塔数值积分法进行动力学数值仿真,探讨了V形兜孔的几何参数对保持架打滑及稳定性的影响,分析了兜孔优化后在不同转速下保持架的打滑特性、稳定性及兜孔/滚子碰撞特性,结果表明,V形兜孔的几何参数对保持架打滑及稳定性的影响显著,在30000~60000r/min的转速范围内,优化轴承保持架的打滑率明显低于普通轴承,涡动半径明显小于普通轴承,滚子对兜孔局部碰撞的力幅值和频率也明显小于普通轴承。

Cage slip and dynamic instability present challenges to the mainshaft cylindrical roller bearing of aero-engines.This paper proposes a novel cylindrical roller bearing with a V-shape pocket,and studies its cage slip and stability.Using the Hertz contact theory,the elastohydrodynamic and hydrodynamic lubrication formulas,and the Newton-Euler dynamics theory,we build a dynamics model of the bearing under radial rigid loads.Subsequently,based on the variable-step RungeKutta numerical integration method,the dynamics simulation of the bearing is conducted,the effects of the geometric parameters of the V-shape pocket on the cage slip and stability are discussed,and the cage slip characteristics,the cage stability and the roller-pocket collision characteristics of the bearing with the optimized pocket are analyzed at various high rotational speeds.The results show that the influences of the geometric parameters of the V-shape pocket on the cage slip and stability are remarkable;compared with the general bearing,within the rotational speed range of 30000~60000 r/min,the cage slip ratio,the cage whirl radius,and the force amplitude and frequency of the roller-pocket local collisions of the optimized bearing are significantly lower or smaller.