不同预负荷对椭圆滑动轴承的静动特性的影响

流体动压径向滑动轴承以润滑油为工作介质实现重载转子的润滑,在重型和大型以及超大型机械中应用广泛。建立椭圆滑动轴承的径向流体动压滑动数值模型,通过Dyrobes软件分析不同预负荷条件下椭圆滑动轴承对油膜刚度与阻尼、油膜压力、Sommerfeld数和雷诺数、摩擦功耗的影响。分析表明适当的增加预负荷能改善润滑条件,第二油楔面的形成有利于增加转子的稳定性。上述分析结果对椭圆滑动轴承的设计提供了设计参考依据。     

想想看

1.当人们拆开减速机箱盖或打开机床变速箱时,就可以清楚的看到从高速轴到低速轴,轴颈逐渐变粗,齿轮的轮齿也逐渐变大,这是为什么?2.减速机有用滑动轴承也有用滚动轴承,这是为什么?     

中板2300劳特式轧机的设备检修与安装

对中板2300劳特式轧机三重齿轮座及减速机剖分式滑动轴承的顶间隙及侧间隙进行调整,使得润滑油膜的形成更加流畅,保证了润滑效果,轴瓦的使用寿命延长了1倍.     

减速机高速齿轮轴断裂失效分析

减速机在工业产生当中具有较为广泛的应用,但是减速机在使用过程当中高速齿轮轴经常发生断轴现象,甚至还会带来一定的安全隐患。为了解决减速机高速齿轮轴断轴问题,首先从材料问题、轴内存在夹杂物、装配工艺以及管理不到位四个方面对导致减速机高速齿轮轴断裂的因素进行了分析,最后从选择合适的产品、进一步完善减速机的安装工艺以及加强日常管理与维护三个方面论述了具体的解决对策。     

穿孔机减速机国产化扩能改造改进

穿孔机轧制高合金厚壁管时,出现输出万向联轴器发生裂纹,减速机噪声和振动异常,电机电流超出等异常情况。从对现场轧制工况、进口减速机齿轮强度校核、及对同型号机组进行类比分析等方面,进行了改造的可行性分析。得出该减速机原设计对工况考虑不足,使用能力偏低,不能满足在实际最大载荷下的转矩要求,需要对现有减速器进行扩能改造。按承载尖峰载荷的能力为现在的1.5倍为改造目标,进行国产化扩能改造。用增加中心距、增大齿轮模数等方法,对该减速机进行扩能改造。该改造方案已设计完成,且经通过了主机设计院和用户单位专家的评审确认。     

影响长轴液下泵滑动轴承的因素分析

对长轴液下泵滑动轴承材料的选用以及对滑动轴承的结构和相应的润滑方式进行分析,总结出影响滑动轴承正常运行的原因。     

双油膜浮动轴承均载行星齿轮传动技术研究

本文从动压轴承弹性油膜内压力方程一雷诺方程的基本原理分析了滑动轴承、共转轴承、双油膜浮动轴承的弹性油膜的弹性浮动量对行星轮载荷均衡性能的影响，并设计了用于试验的行星减速机，试验台及齿根应力测试装置，进行了滑动轴承和双油膜浮动轴承的均载性能试验，经数据分析、处理，得出用双油膜浮动轴承时的载荷不均衡系数小于１．１５。据了解，这是国内首次在产品样机上得到的研究结果。     

中板2300劳特式轧机的设备检修与安装

对中板2300劳特式轧机三重齿轮座及减速机部分式滑动轴承的顶间隙及侧间隙进行调整，使得润滑油膜的形成更加流畅，保证了润滑效果，轴瓦的使用寿命延长了1倍。     

滑动轴承结构参数对转子系统阻尼临界转速的影响

以三油楔固定瓦滑动轴承(不同心)-弹性Jeffcott转子系统为研究对象.在计及滑动轴承刚度和阻尼特性的基础上,通过编程计算,求解了滑动轴承的动特性系数和轴承-转子系统的阻尼临界转速.获得了轴承结构参数--宽径比、最小间隙比和预负荷系数对系统阻尼临界转速的影响规律.结果表明,轴承结构参数对系统阻尼临界转速产生影响;阻尼临界转速高于不考虑轴承阻尼时的系统临界转速;增大宽径比,减小最小间隙比和预负荷系数使系统阻尼临界转速增大.     

F3精轧减速机高速轴轴窜分析

介绍承钢1780 mm精轧机F3减速机高速轴的轴窜问题,通过对轧制过程中高速轴的受力分析,结合现场检测,找出导致减速机高速轴发生窜动现象的原因,提出了具体改进措施,有效解决了轴向窜动现象,防止出现重大设备事故。     

游隙对滚滑轴承内部载荷及应力影响的研究

滚滑轴承是一种新型轴承,可应用于风力发电机齿轮箱。根据滚动轴承基本原理和接触力学原理,建立滚滑轴承有限元模型,研究滑块与内外套圈滚道之间的游隙对滚滑轴承内部载荷及应力的影响,得到不同游隙时不同大小载荷工况下典型工作位置处滚滑轴承的内部载荷与应力分布规律。在研究中,提出滚滑轴承临界载荷的概念。研究结论可以为滚滑轴承的基础理论研究和参数优化提供参考。     

WEC Formation in Rolling Bearings under Mixed Friction: Influences and “Friction Energy Accumulation” as Indicator

White etching cracks (WEC) can lead to premature rolling contact fatigue. Possible drivers of WEC can be mixed friction, sliding between rolling elements and raceways, electrical current, critical additives, and water-contaminated lubricant. With respect to WEC failures induced by sliding between rolling elements and raceways under mixed friction, an approach is presented that can explain the experimentally observed failure characteristics of cylindrical roller thrust bearings. Variants of the bearing were tested using a WEC-critical lubricant. The tests showed that not only the contact pressure and sliding between rolling elements and raceways but also the lubrication conditions (specific film thickness) and the frequency of the contact load cycles have an influence on WEC life. These influences are reflected best by a newly introduced characteristic parameter termed friction energy accumulation. As far as WEC failures induced by sliding under mixed friction are concerned the friction energy accumulation could be used for a comparative assessment of the WEC risk of arbitrary rolling bearing applications. A link between the friction energy accumulation and the absorption of hydrogen is discussed and can provide further explanations for the susceptibility of bearing components to WEC formation.     

气体涡轮流量计中动压气体轴承的研究

气体涡轮流量计主轴承大多采用油润滑的滑动轴承或滚动轴承,存在较大的局限性。采用螺旋槽气体轴承,设计了一种气体涡轮流量计。按最大稳定性的原则,利用MATLAB软件,系统地分析了在气体涡轮流量计中动压气体轴承的结构形式对其载荷及稳定性的影响,得到了气体涡轮流量计中动压气体轴承的可行工作范围。     

轴表面DLC涂层对滑动轴承润滑承载性能的影响*

为研究轴表面类金刚石(DLC)涂层对滑动轴承承载性能的影响,利用滑动轴承实验台测试轴线对中及倾斜工况下灰铸铁、铝合金和聚酰亚胺(PI)涂层轴承分别与40Cr钢轴和DLC涂层轴配合时的轴心轨迹和极限载荷,并测试3种材料与40Cr钢和DLC涂层的摩擦因数。结果表明:相较与40Cr钢配合,灰铸铁和铝合金与DLC涂层配合时摩擦因数减小,重载下轴承偏心率减小,轴线对中工况下灰铸铁轴承的极限载荷超过10 MPa,铝合金轴承的极限载荷增大到7.8 MPa(增大1.1倍),轴线倾斜工况下轴承抱死失效时边缘变形增大;但重载下PI涂层与DLC涂层配合时摩擦因数增大,轴线对中工况下轴承极限载荷减小至3.6 MPa(减小44%),轴线倾斜工况下轴承抱死失效时边缘变形减小。     

Study on Rolling Contact Fatigue in Hydrogen Environment at a Contact Pressure below Basic Static Load Capacity

A method to determine the shoulder height in an angular contact ball bearing using a 3D contact analysis is proposed. The load analysis was performed by calculating the distributions of internal loads and contact angles for each rolling element. From the results of the bearing load analysis and the contact geometry between the ball and raceways, 3D contact analyses using an influence function were conducted. The algorithm developed was applied to an angular contact ball bearing for an automotive wheel. The effects of axial load on contact pressure at the inner and outer raceways were evaluated and the critical axial loads in the present shoulder height were calculated. The critical shoulder heights were also determined when the bearing was subjected to a practical load for a steel ball bearing. The proposed methodology is generally applicable for the purpose of reducing the material cost and improving the efficiency of the bearing design process.     

Wear transitions and mechanisms in lubricated sliding of a molybdenum coating

Wear tests were performed for a Mo coating sliding against bearing steel specimen under boundary lubrication conditions. Results were compared with (i) hardened carbon steel sliding against bearing steel and (ii) Mo coating sliding against boron cast iron. Tests indicated that the wear resistance of the Mo coating was superior to that of the uncoated hardened steel. The initial surface topographies of the coatings were suitable to facilitate the transfer of the applied load directly onto the phases and prevented the softer phase directly involved in the wear process. The morphology of the transfer layer formed on the Mo coating was identified by X-ray diffractometry. And the layers were expected to supply an in situ lubrication effect. The wear rates of the coating against a steel slider were lower compared with those worn against a cast iron slider. With increasing applied load, the probability of the harder phases crack and fracture increased until the fraction of the unfragmented phases on the contact surfaces was no longer adequate to support the load. The dominant wear mechanisms in each wear regime were discussed.     

三环式少齿差传动的动力学分析

建立了三环式少齿差传动的动力学方程，利用数值方法进行了实例计算和分析。解释了三环式传动克服死点的机理；给出了环板轴承载荷随转角变化的规律；分析了转速对环板轴承载荷的影响。     

圆锥滚子轴承的性能测试分析研究

以GZ-50A双控滚动轴承性能测试分析试验台为平台,以通用圆锥滚子轴承为研究对象,对圆锥滚子轴承进行了性能测试分析实验研究开发。研究了圆锥滚子轴承径向载荷分布变化特点及轴向载荷对滚动轴承径向载荷分布的影响,通过圆锥轴承元件上载荷波动特性曲线分析了特定工况下圆锥轴承缺陷的潜在原因,提出相应的改进措施并分析圆锥滚动轴承组的综合性能和最佳受力状况。     

汽车主减速器轴承受力分析及选型系统开发

以某货车主减速器轴承为研究对象,对其进行了力学分析,并在此基础上推导了动载荷和额定寿命的计算公式。基于VC#.NET技术开发了主减速器轴承设计计算和选型软件,该系统功能全面、人机界面友好,与传统的设计方法相比,提高了精度和效率。     

The effect of changing the rolling direction on the rolling contact fatigue lives of annealed and case-hardened steel rollers

The effects of changing the rolling direction and of repeated loading on the rolling contact fatigue lives of annealed 0.45% carbon steel rollers and case-hardened nickel-chromium steel rollers under conditions of sliding rolling contact were studied. The influence of plastic flow in the subsurface layer on the rolling fatigue life was examined. The increase in the rolling fatigue life of an annealed steel roller due to a change in the rolling direction was significant, especially when the rolling direction was changed just before the formation of macroscopic surface cracks and pits. The effect with case-hardened steel rollers was negligible. The varying effects of changing the rolling direction on the rolling fatigue life were due to differences in work-hardening and the extent of plastic flow in the rollers.