脂润滑轴承润滑剂迁移机理

本文详细讨论了脂润滑油轴承接触区附近润滑剂的几种迁移现象。这些迁移现象包括基础油的分油,渗透及蒸发,在剪切,挤压,振动作用下的粘附迁移,在温度梯度下的表面迁移,在表面张力作用下的回流迁移,在出口空穴所产生的液滴迁移以由于氧化造成的润滑剂永久损失。     

脂润滑轴承润滑剂迁移机理浅析

讨论了脂润滑轴承接触区附近润滑剂的几种迁移现象,有的迁移现象使入口区附近的润滑剂损失,有的使入口区附近的润滑剂得到补给,因此,在接触区附近存在一个迁移的动态平衡,这样就保证了脂润滑轴承长期可靠的运转.     

脂润滑轴承搅动阻力的测试方法

搅动阻力在脂润滑轴承摩擦力矩中占主要地位，因而对轴承寿命有一定的影响，文中就搅动阻力的测试提出了动量矩定理测试新方法，论述了其原理，设备和数据处理方法，并通过实例证明之。附图３幅，参考文献４篇。     

低噪声密封轴承润滑脂选用及机理分析

对轴承行业主要使用的低噪声密封轴承润滑脂现状进行评述，并在此基础上利用动态离心分油试验机、表观粘度试验机、流动压力测试仪、速度型和加速度型轴承振动测量仪等仪器，进一步分析了润滑脂对密封轴承振动噪声性能的影响因素及其机理。     

气体润滑轴承技术的应用及发展趋势

气体润滑轴承是一种以气体作为润滑剂的滑动轴承.自二十世纪六十年代以来,随着原子能、航天技术、微电子学、信息技术及生物工程等新兴科学技术的发展,加工精度越来越高,从mm到μm、亚微米,现在已经发展到mm水平,并向着原于晶格尺寸(亚纳米)水平迈进,称之为超精密加工.加工精度的高指标,形成对加工设备的高要求,推动了它的进步.无论是精密加工机械,还是测量仪器,都对其机械部分提出了高精度、高速度、高分辨率、热稳定性好,低振动、爬行小、少污染及降低设备成本等方面的严格要求.人们在实践中发现,气体静压轴承正是解决上述困难的重要途径.这是因为气体静压轴承有以下几方面的特     

某高速脂润滑轴承强制冷却分析

轴承发热对其性能有着显著影响。为了分析冷却条件对冷却效果的影响,对滚动轴承的强制散热系统进行了建模,并利用该模型对某型号轴承在不同散热条件下的温度场进行定性分析。     

水润滑塑料合金轴承润滑机理研究

水由于粘度极小而很难形成流体动压润滑，而非刚性轴承--塑料合金轴承却以水作为润滑介质。本文应用流体力学理论推导了水润滑塑料合金轴承的雷诺方程，研究了该轴承润滑机理的基础理论。     

减速箱轴承润滑改良及漏油防治

一、问题的提出 我们在对进口成套设备中的减速箱进行国产化代用时,往往感到即使是国内最优秀的减速箱生产厂家,他们所生产出的减速箱在对轴承的润滑上考虑得不够全面,以致轴承部温升过高或漏油,从而大大降低了轴承的使用寿命。更有甚者,减速箱从安装到投入运行在不到一个工作班的时间内就发生了烧轴承现象,直接影响了生产的正常进行。我公司自1989年开始首先在皮带运输系统上使用了国内某厂生产的减速箱。该减速箱先是发生了输入轴直交齿部轴承因供油不足而烧坏的现象,经改进后又因进油过多未能及时回油而发生了严重漏油(喷射)现象。因此改良减速箱轴承部的润滑状况、对漏油的防治,是对减速箱改进的重要措施。本文着重讨论减速箱轴承部的润滑问题。     

脂润滑轮毂轴承弹流润滑数值分析

基于Ostwald模型建立脂润滑控制方程,运用多重网格法求得等温线接触脂润滑弹性流体动力润滑数值解,得到钢球-沟道的压力分布、油膜形状及最小油膜厚度。针对轿车轮毂轴承的典型应用工况条件,分析工况参数对油膜压力分布和油膜形状的影响。结果表明:脂润滑弹流膜具有与油润滑膜相同的二次压力峰和出口颈缩现象。在轿车轮毂轴承可能的承载条件下,随着载荷的减小,二次压力峰的高度降低,其位置向入口区移动;一定承载条件下,速度增加时,膜厚相应增加,油膜的平行部分缩短,二次压力峰的高度增加,其位置也向入口区移动;一定承载和卷吸速度下,润滑脂流变参数增大时,二次压力峰的高度升高,其位置向入口区移动,膜厚相应增加。     

Running Torque of Ball Bearings with Polymer Lubricant (Effect of the Enclosure Form of Polymer Lubricant)

This article deals with the running torque of ball bearings with polymer lubricant (solid composite material composed of plastic impregnated with a large amount of oil or grease). The results of the experiment showed that the measured running torque of ball bearings with polymer lubricant was affected by the enclosure form of the polymer lubricant. With regard to ball bearings with different enclosure forms of the polymer lubricant, the measured running torque difference was not affected significantly by the rotational speeds or the axial loads. The analytical results showed that the running torque difference was caused mainly by the friction (depending on the enclosure form of the polymer lubricant) between the balls and the polymer lubricant (or cage).     

Dry Lubricated Bearings for Operation in a Vacuum

Ball bearings incorporating two different types of dry self-lubricating retainer materials were successfully operated in a vacuum over the pressure range of 1 × 10^?7 to 2 × 10^?8 (mm of H) torr for prolonged periods of time. A 20 mm bore ball bearing of AISI M-10 tool steel with a filled plastic retainer was operated over a range of temperatures from 100 F to 160 F and similar bearings with filled metal retainers were operated over a temperature range of ?300 F to 450 F, at radial loads up to 75 pounds. Other ball bearings using both types of self-lubricating retainer materials were operated in electric motors in the vacuum environment.

In selecting the dry self-lubricating materials for the ball bearing tests, plastics powders and composite materials were screened in an inert atmosphere to determine wear and friction characteristics. Each of the materials that exhibited desirable lubricating properties was then subjected to a vacuum at elevated temperatures to determine the rate of outgassing. These materials were then satisfactorily used as the dry self-lubricating retainers in the 20 mm bearings which operated in the vacuum environment.     

双分散型两相润滑剂的润滑性能及机理的研究

本文研究了二氧化硅和石墨或MCA粒子双分散型两相(液—固)润滑剂的摩擦磨损特性,这种双分散型的两相润滑剂的抗磨性能均较基础油为优。其中二氧化硅和石墨双分散型的几种油样的抗磨性能极其近似,说明抗磨性能与粒子含量无关。其摩擦系数随载荷的提高而显著下降,但达到一定的临界载荷值后,又趋于平稳,根据这些实验现象,笔者着重研究了双分散型润滑剂不同种粒子的协同作用方式,建立了相应的物理模型,并以此模型来分析实验现象产生的机理。     

Mechanism of Crack Growth in Lubricated Rolling/Sliding Contact

In order to explain the mechanism of rolling-contact fatigue crack growth analytically, fracture mechanics are applied to a semicircular surface crack inclined at an angle to the elastic half-space loaded by Hertzian stresses.

It is shown that the surface traction is the controlling factor for lubricant seepage into the crack and for shear mode crack growth rate. It is also clarified that the generation of pits results from tensile mode crack growth mainly due to the oil hydraulic pressure action.     

Power Loss Predictions in High-Speed Rolling Element Bearings Using Thermal Networks

In high-speed rolling element bearings (REB), the lubricant is used to separate the mating surfaces but also to cool down the parts while the system is in operation. In the context of optimizing oil circuits, a clear understanding of the lubricant cooling mechanisms is therefore required in order to reach a compromise between a good cooling capacity and the constraints on mass, size, and power. In this article, a model is presented that makes it possible to predict temperature distributions in high-speed thrust ball bearings. It is found that the prediction or measurement of global power loss cannot discriminate between several combinations of traction and drag forces. On the other hand, the predicted temperature distributions appear as very sensitive to the relative importance given to hydrodynamic rolling tractions or drag losses. Based on these findings, a methodology is suggested in order to define the most realistic power loss models to be used in high-speed REB simulations.     

润滑油温度对发动机的影响

润滑油温度过低、过高直接影响发动机的机械效率、功率和使用寿命。本文主要分析了润滑油工作温度异常对发动机各种工况下的影响因素、损伤机理、使用技术及对策。     

含氟润滑油脂减摩性能及摩擦机制分析

研究分析了聚四氟乙烯润滑油脂的减摩性能,得出了聚四氟乙烯润滑油脂摩擦因数与转速、温度和载荷变化关系。利用SEM和EDS对3种润滑剂摩擦膜进行形貌和能谱分析,认为聚四氟乙烯润滑油脂减摩是表面物理吸附膜和化学迁移膜共同作用的结果。     

Lubricant for Heavily Loaded Slow-Speed Journal Bearing

Slow-speed journal bearings subjected to heavy loads operate in a mixed/boundary lubrication regime. Clearance and lubricant play very important roles in reducing the wear and friction in these bearings. In the present article, an experimental study on heavily loaded slow-speed journal bearings with various radial clearances lubricated with three different lubricants is presented. Lubricants with varying viscosities and containing different percentages of antiwear additives have been used. Bearing surface roughness and out-of-roundness are treated as noise parameters. The results of friction coefficient and total wear have been reported. The experimental results suggest that a lubricant with high viscosity and antiwear additives significantly reduces the coefficient of friction and amount of wear under varying bearing clearances, circularity, and cylindricity. The use of such a robust lubricant may obviate the effect of manufacturing uncertainties. This results in reduction of manufacturing and measurement costs.