考虑热流固耦合的角接触滚动轴承动力学特性及打滑状态分析

Analysis of Dynamic Characteristics and Skidding State of Angular Contact Bearing by Thermo-hydro-elasto-dynamic Coupling Model

轴承滚珠-滚道之间的打滑易使滚动体滚道划伤并导致明显的温升。为讨论打滑现象及其导致的问题,提出一种热流固耦合动力学模型。模型引入了轴承部件的热变形,打滑导致的温升,供油区的润滑油混合模型,保持架-引导圈之间的流体动压模型,以及作用在滚珠和保持架上的碰撞力和切向摩擦力,并考虑了保持架及滚珠的打滑程度、轴-轴承-轴承座组件的温升分布、热弹性变形等动静态参数的影响。通过对比7307AC轴承在一系列运行工况(运行速度,轴向载荷和润滑油量)下的打滑试验结果,验证了热流固耦合模型的准确性和有效性。结果表明,相同轴向预载时转速升高打滑程度显著加剧;最高温升及热变形也随之增加。乏油润滑下(0.4 L/min),保持架总体打滑率低于满油润滑(1.2 L/min),但轴承滚道的局部最大热变形达到滚珠-滚道径向游隙的4倍。基于润滑油混合模型发现,喷嘴水平对称布置相较于垂直布置冷却效果更好。

The ball-raceway skidding of the angular contact ball bearing are prone to scratch the rolling element and raceway,leading to a significant temperature rise.To discuss the skidding behavior,a thermo-hydro-dynamic coupling dynamics model is proposed in this article.Thermal deformation and temperature rise model,lubricant mixing model,hydro-dynamic pressure model for describing the interaction of cage and guide ring,and ball-cage interactions are introduced to the model.The dynamic and static characteristics such as the degree of skidding,the temperature distribution,and the thermoelastic deformation are discussed here.The skidding test of 7307AC bearing under different operating conditions is referred to validate the proposed model.The results show that the degree of skidding increases significantly as the speed increases;the maximum temperature and thermal deformation increase correspondingly.The skidding degree under starvation lubrication(0.4 L/min)is lower than full flood lubrication(1.2 L/min).The maximum thermal deformation on the bearing raceway reaches 4 times of the ball-raceway radial clearance.It is found that the oil spray nozzles arranged horizontally and symmetrically have a better cooling effect than those arranged vertically.