高速滚动轴承的混合润滑性能及疲劳寿命研究

发布时间：2018-12-27 12:11

【摘要】：航空科学技术的进步和发展要求未来航空发动机主轴轴承能够在高温、高速和重载工况下可靠运转，因而滚动轴承的设计及制造技术面临着严峻的挑战。在上述工况下，滚动体与滚道处于更加苛刻的混合润滑状态，润滑油的非牛顿效应和表面形貌效应将对混合润滑性能和滚动接触疲劳寿命产生重要影响；而轴承在高速运转时滚动体的滑动速度、自旋速度以及离心力也将对热弹流润滑性能产生影响，进而改变轴承的温升、功率损失和疲劳寿命。然而目前这些方面都缺乏系统的理论研究。本文针对航空发动机主轴轴承的工况条件，在考虑非牛顿和表面形貌效应的混合润滑研究基础上，提出了高速滚动轴承的疲劳寿命预测方法，对混合陶瓷轴承和全钢轴承的温升特性、功率损失和疲劳寿命进行了系统研究。主要内容如下：研究了润滑油非牛顿特性、接触副材料、表面形貌和椭圆率等对混合润滑性能的影响。结果表明：润滑油的特征剪应力增大会引起膜厚增大但同时会导致压力波动加剧；具有横向纹理特征的粗糙表面对混合润滑性能更为有利；粗糙度参数偏态和峰度对膜厚的影响作用较小，但是对最大压力的影响较为明显；椭圆率增大会导致膜厚和最大压力的减小。在考虑非牛顿和表面形貌效应的混合润滑研究基础上，提出了三维次表面应力和疲劳寿命预测方法，研究了润滑油的非牛顿特性、接触副材料和几何参数、表面形貌等因素对次表面应力和疲劳寿命的影响。结果表明：润滑油的特征剪应力增大会引起摩擦系数和次表面应力的增大，最终导致疲劳寿命的减小，而润滑油黏度对疲劳寿命的影响作用与润滑状态有密切关系；在混合润滑状态下，随着粗糙表面由纵向纹理特征转变为横向纹理特征，次表面应力减小而疲劳寿命增加；粗糙度参数偏态值的增大会导致疲劳寿命单调减小，而疲劳寿命随着峰度的增大呈现明显的波动变化；峰度值增大，偏态变化对疲劳寿命的影响作用更明显，反之亦然。椭圆率的增大有利于次表面应力的减小和疲劳寿命的增加。建立了考虑自旋和润滑油非牛顿效应的点接触热弹流润滑模型，发展了高效的数值求解方法，研究了卷吸速度、滑滚比和自旋速度对温升特性、功率损失及疲劳寿命的影响。结果表明：卷吸速度对疲劳寿命的影响与椭圆率有密切关系；滑滚比增大会导致温度显著升高和疲劳寿命的减小，并且滑滚比的影响与卷吸速度有密切关系；滚动体的自旋速度增大会导致油膜温度升高和功率损失增大，虽然自旋会引起摩擦系数的减小，但是自旋的存在会降低疲劳寿命。将点接触热弹流润滑模型与滚动轴承拟静力学模型相结合，，研究了混合陶瓷球轴承和全钢轴承的温升特性、功率损失和疲劳寿命。结果表明：轴承滚道曲率比增大会引起总功率损失的显著减小；与全钢轴承相比，在低速时，混合陶瓷球轴承的最大接触压力和油膜温度更高而疲劳寿命更短；在高速时，混合陶瓷轴承具有更低的油膜温度和更长的疲劳寿命。通过实验研究了陶瓷球和钢球在不同润滑状态下的摩擦学性能。结果表明：在混合润滑状态下，陶瓷球的摩擦系数要大于钢球的摩擦系数；在全膜润滑或近似全膜润滑状态下，陶瓷球和钢球的摩擦系数几乎没有差别；在考虑离心力引起的差异后，陶瓷球的摩擦系数要小于钢球的摩擦系数。
[Abstract]:The progress and development of aviation science and technology require that the main shaft bearing of aeroengine can operate reliably under high temperature, high speed and heavy load, so the design and manufacturing technology of rolling bearing face serious challenge. under the working condition, the rolling body and the rolling track are in a more severe mixed lubrication state, the non-Newtonian effect and the surface appearance effect of the lubricating oil can have an important influence on the mixed lubricating property and the rolling contact fatigue life, and the sliding speed of the rolling body when the bearing is at high speed, The spin speed and the centrifugal force will also have an effect on the lubrication performance of the thermal elastic flow, thus changing the temperature rise, the power loss and the fatigue life of the bearing. However, there is a lack of systematic theoretical research in these aspects. In this paper, the fatigue life prediction method of high-speed rolling bearing is put forward based on the mixed lubrication study of the non-Newtonian and surface morphology effects, and the temperature rise of the mixed ceramic bearing and the full steel bearing is put forward. System research on the performance, power loss and fatigue life of the system The main content is, for example, The non-Newtonian behavior of the lubricating oil, the contact sub-material, the surface morphology and the ellipticity of the lubricating oil were studied. The results show that the increase of the characteristic shear stress of the lubricating oil can cause the increase of the thickness of the film, but at the same time, the pressure fluctuation is increased; the rough surface with the transverse texture feature can be more favorable to the mixed lubricating property, and the influence of the roughness parameter deviation state and the kurtosis on the film thickness It is small, but the effect on the maximum pressure is more pronounced; the increase in the ellipticity results in film thickness and maximum pressure Based on the study of mixed lubrication with non-Newtonian and surface morphology effects, the three-dimensional surface stress and fatigue life prediction method are put forward, the non-Newtonian characteristics of the lubricating oil and the contact sub-materials are studied. and other factors such as geometric parameters, surface morphology and the like, The results show that the increase of the characteristic shear stress of the lubricating oil can cause the increase of the friction coefficient and the secondary surface stress, which can lead to the decrease of the fatigue life, and the effect of the viscosity of the lubricating oil on the fatigue life is closely related to the lubrication state. Under the condition of lubrication, as the rough surface is changed from the longitudinal texture feature to the lateral texture feature, the secondary surface stress is reduced and the fatigue life is increased; the increase of the partial state value of the roughness parameter can lead to the monotonicity of the fatigue life, and the fatigue life is obviously changed with the increase of the kurtosis; The peak-to-peak value is increased, and the effect of the change of the partial state on the fatigue life is more obvious and vice versa. The increase of the ellipticity is beneficial to the reduction and fatigue of the secondary surface stress In this paper, a point-contact thermal elastic flow lubrication model considering the non-Newtonian effect of the spin and the lubricating oil is established, and a high-efficiency numerical solution method is developed to study the temperature rise characteristics, power loss and the spin speed of the rolling speed, the slip ratio and the spin speed. The results show that the effect of the rolling speed on the fatigue life is closely related to the ellipticity. The increase of the sliding ratio can lead to a significant increase of the temperature and the decrease of the fatigue life, and the effect of the slip ratio and the roll-out ratio The speed is closely related; the increase in the spin speed of the rolling element results in an increase in the temperature of the oil film and an increase in the power loss, although the spin may cause a decrease in the coefficient of friction, but the presence of the spin The temperature rise characteristics of the mixed ceramic ball bearing and the full steel bearing are studied by the combination of the point contact thermal elastic flow lubrication model and the rolling bearing quasi-static model. Power loss and fatigue life. The results show that the increase of the curvature ratio of the bearing raceway can cause a significant reduction in total power loss. Compared with the full steel bearing, the maximum contact pressure and the oil film temperature of the mixed ceramic ball bearing are higher than that of the full steel bearing. shorter life; at high speeds, the hybrid ceramic bearings have a lower oil film temperature The fatigue life of the ceramic ball and the steel ball is studied by the experiment. The results show that the friction coefficient of the ceramic ball is greater than that of the steel ball under the condition of mixed lubrication, and the friction coefficient of the ceramic ball and the steel ball is almost no difference under the condition of full-film lubrication or approximate full-film lubrication. the friction system of the ceramic ball after considering the difference caused by the centrifugal force
【学位授予单位】：北京理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TH133.33

【参考文献】