滚动轴承疲劳破损过程分析

对轴承在弹性流体润滑状态下的疲劳过程进行了分析 ,并指出疲劳破损有两种 :一种是部分轴承零件出现剥落的小坑 (点蚀 ) ,深度与在滚动方向上测得的接触面宽度属同一数量级。第二种是表层剥落 ,深度较浅 ,一般几微米或不足一微米。其根源一是非均质的表面及夹杂物 ,根源之二是轴承零件磨削时形成的硬化层。附图 5幅 ,参考文献 10篇。     

滚动轴承接触疲劳失效的分析方法北大核心

滚动轴承常见的失效形式有疲劳剥落、磨损、塑性变形、腐蚀、烧伤、电腐蚀及保持架损坏等。以某套损伤轴承的失效分析为例,对轴承接触疲劳失效的分析方法进行了探讨和总结。     

汽车轮毂轴承疲劳失效分析

结合轮毂轴承工作特点及对失效轴承的组织、硬度、材料和润滑状况分析,指出造成轴承疲劳失效的原因与轴承材质、工艺无关,而润滑不良或游隙过大才是轮毂轴承失效的主要诱因.     

滚动轴承失效分析概论

滚动轴承零件的失效分析是提高轴承可靠性系统工程中的重要一环，也是一门跨学科的新技术领域，引起人们的关注。介绍了轴承零件失效的基本形式、影响因素、分析方法、表面质量分析、轴承失效预测以及预防技术的发展现状。参考文献１１篇。     

滚动轴承的快速疲劳寿命试验及可靠性分析

介绍６３０８轴承的常规疲劳试验与加速疲劳试验，并根据试验结果和数据的多种方法处理，探索该型轴承疲劳失效的规律。在较大的Ｐ／Ｃ下，用较短的试验时间获得轴承的特征寿命值，来推断常规条件下的轴承特征寿命值，从而能有效地利用试验数据，分析轴承的可靠性。附图１幅，表３个，参考文献８篇。     

滚动轴承的失效研讨

从滚动轴承失效形式出发，列举滚动轴承的换效实例，分析、找出失效原因，找出失效原因，提出今后设计、制造注意的问题。     

提高滚动轴承疲劳寿命的主要技术措施

轴承疲劳寿命是一个多因素综合影响的结果。从设计技术、制造技术、材料技术和润滑技术方面提出了相应的保证和提高措施     

滚动轴承故障诊断机理研究

滚动轴承是常用机械组件,对其故障机理和诊断方法进行研究,能有效提高其安全性和可靠性。通过建立滚动轴承非线性动力学模型,计算出轴承故障振动响应。在模型计算结果中添加谐波分量和白噪声干扰,通过EEMD分解和峭度分析方法,抑制噪声干扰,突显故障特征信号。以深沟球轴承6205为例验证了故障诊断方法的有效性和动力学模型的正确性。首先建立非线性动力学模型,通过计算分析,揭示故障机理。利用基于EEMD的故障诊断方法,有效地突显故障信号,并验证动力学模型正确性。     

Fatigue Behavior of Hybrid Ceramic Ball Bearings in Liquid Nitrogen

Hybrid ceramic ball bearings, which are composed of silicon nitride (Si₃N₄) balls, ANSI 440C stainless steel rings and PTFE based composite retainers, are tested at high speed and heavy loading in cryogenic conditions. The rolling contact fatigue behavior of steel rings and ceramic balls in liquid nitrogen is analyzed. In addition, four-ball fatigue testing was done at room temperature with oil lubrication. The crush load of ball against ball in liquid nitrogen, which directly relates to the inner quality of the balls, is also evaluated. The results show that the spalling of silicon nitride balls, rather than micro pitting on the steel raceways, is the main cause for the failure of the hybrid ball bearings in liquid nitrogen. The fatigue mechanism of the ceramic balls is similar to that of ceramic balls at room temperature, but the characteristics of crack propagation are different because of differences between the cryogenic liquid medium and oil. Although most of the fatigue cracks originated from internal defects within the ceramic balls, the silicon nitride balls exhibit a high load capacity. When silicon nitride balls are loaded against steel balls, the steel balls are crushed while the silicon nitride balls do not exhibit plastic deformation. When ceramic balls with a 11.113 mm diameter are loaded against each other, crushing takes place at a nominal contact stress of 27～29 GPa.     

润滑脂铁谱分析的研究与应用

本文介绍了一种新的分离润滑脂中磨粒的方法，并对利用分析式铁谱仪和旋转式铁谱仪所制得的谱片进行了比较，指出二者相结合起来的方法是最有效的分析方法，介绍了它们的操作步骤，并通过对大型滚动轴承润滑脂的铁谱分析证明了该方法的有效性。     

A New Form of Rolling Contact Damage in Grease-Lubricated,Deep-Groove Ball Bearings

A new form of rolling contact damage was discovered in the fatigue tests of series 6206 deep groove ball bearings under pure radial load with grease lubrication. The appearance of the damage reveals a few cracks at right angles to the rolling direction of the ball, along with the formation of a dent about 20 μ m deep in the raceway surface. This is found to occur only on the stationary outer ring raceway and the ball surface and is distributed widely within the load zone. Furthermore, under the raceway surface several cracks propagating into the substrate at an angle of about 60-80 degrees relative to the raceway surface are observed not only under the damage site but also in other nearby locations. Only the cracks at the damage position open up to the surface. The grease used for the test contained a lithium complex thickener with mineral oil as the base oil with a kinematic viscosity of 141 mm²/s at 40°C. On the test bearings two pure radial load levels of 9.14 and 12.13 kN were applied. In order to prevent the occurrence of seizure at each load, the speed of the inner ring of the test bearing was maintained at 1800-2500 min^{? 1} and 600-800 min^{? 1}, respectively, to keep the outer ring circumference temperature below 65°C. It is suggested that the damage is caused by metal-to-metal contacts due to lubricant starvation under grease lubrication and to a decrease in oil film thickness due to local increases in temperature.     

汽车分动器齿形链疲劳失效分析

通过汽车分动器齿形链传动总成台架试验,研究了汽车链的疲劳机理,分析了链板疲劳断口的微观形貌,及探讨了汽车链主要零件的塑性变形和循环硬化特性,结果表明,汽车链的疲劳主要与链板的尺寸一致性、热处理和冲裁表面质量有关,指出了提高汽车分动器齿形链疲劳可靠性的措施.     

Crack Propagation of Rolling Contact Fatigue in Ball Bearing Steel Due to Tensile Strain

Crack propagations or failure modes in rolling element bearings, which had been difficult to explain via conventional crack propagation mechanisms such as the orthogonal shear stress mechanism, were discussed from the viewpoint of a tensile strain mechanism. Contact stresses are compressive in three axes, whose values differ from each other; then strain can be tensile in one of these directions, acting at a right angle to the direction of maximum compressive stress. A crack is considered to propagate by this tensile strain. When contact stress is small, a crack produced by some cause can propagate by this elastic tensile strain. When contact stress is large, residual tensile strain is produced by plastic deformation, which can also influence the crack propagation. Several failure modes of rolling element bearings, which had been difficult to explain, were explained by tensile strain.     

Grease Lubrication of Ultra-High Speed Rolling Contact Bearings

The failure mechanisms of grease lubricated ball bearings operating in the DN range from 1.0 × 10⁶ to 2.0 × 10⁶ was studied. A new rig capable of controlled operation of 20 and 25 mm ball bearings at speeds up to 100,000 rpm is described. Ball separator design seems to be a very important factor and a lightweight single piece machines outer ring controlled ball separator appeared to give the best results. In general, mechanical factors such as vibration, bearing design, bearing fit and tolerances, dynamic balance, load alignment, etc., have more influence on the performance of the bearings studied than gross grease variables. Under ideal conditions it is indicated that adequate lubrication with grease is possible for periods over 100 hours. However, under the test conditions generally in existence in the ultra high speed rigs grease lubrication was only adequate for very short periods.

Grease compositional factors leading to better performance are smooth texture and hard consistency. At the temperature investigated diester type oil was slightly superior to mineral oil and greatly superior to silicone oil.     

滚动轴承退化指标选取方法研究

针对滚动轴承退化过程指标选取问题,提出了一种基于噪声辅助的多维EMD(Noise-Assisted Multivariate EMD)和主成分分析(PCA)相结合来提取退化指标的方法。该方法首先利用NA-MEMD对同源双通道信号和噪声辅助通道信号进行分解得到一系列多元IMF分量,然后采用相关系数准则选取敏感分量重构信号,其次计算出轴承退化过程中重构信号的退化指标序列,再根据序列的单调性和鲁棒性,选择优良指标进行PCA融合,最后把第一主成分作为反映滚动轴承退化过程的最终指标。对PRONOSITS平台提供的全寿命周期的数据进行分析,结果表明,在滚动轴承的退化过程中,较单一指标,基于NA-MEMD和PCA融合的指标能够比较完整的表征滚动轴承的退化过程。     

关节轴承静态疲劳特性的响应面优化

针对某一炼钢厂250t转炉水平悬挂装置的失效问题,分析得知由向心关节轴承疲劳破损引起.以关节轴承为研究对象,通过静力学仿真以及疲劳寿命计算获得关节轴承在转炉倾转至90°的严峻工况下的静态疲劳特性.以关节轴承弹性模量、内圈边缘倒角r1a和r1b及工作温度为约束,最大等效应力、最小疲劳寿命为目标函数,结合响应面法并选用NS...