MoS_2固体润滑轴承跑合技术实践

介绍了航天用MoS_2固体润滑轴承润滑膜的结构和磨损机理,分析了跑合对该类轴承应用的重要性以及对润滑膜形貌和性能的影响。结合固体润滑轴承的跑合实践,总结并剖析了MoS_2固体润滑轴承跑合过程中常见的问题及解决措施。采用变载荷跑合,用绸布擦拭清洗沟道,合理设定跑合参数,通过跑合带宽度均匀性评估跑合效果等能够有效改善固体润滑膜的润滑效果。     

太空用固体润滑轴承试验分析

以轴承的固体润滑为研究对象，进行了轴承跑合试验、轴承寿命及性能试验研究分析，为采用固体润滑技术解决轴承空间润滑问题提供了依据。     

固体润滑轴承的变预载跑合系统设计与试验

分析了MoS2薄膜用于固体润滑轴承的润滑机理,阐述了对MoS2固体润滑轴承进行跑合的必要性,详细介绍了所设计的变预载轴承跑合系统,进行了轴承的变载荷跑合试验,并对试验结果进行了简要分析。     

一种基于球面并联机构的关节轴承跑合运动方案设计

以向心关节轴承跑合为例,分析了当前常规轴承跑合技术的缺点和优点,结合二自由度球面并联机构运动特点,提出了一种新型的轴承跑合方案。该方案针对向心关节轴承在工作中运动的特殊性,即因为该轴承内外圈存在三自由度相对转动的运动,尝试性地引入了球面并联机构。通过计算和分析二自由度球面并联机构的运动空间,并与向心关节轴承倾斜角相比较,验证了该方案的可行性。该方案为关节轴承跑合设备的研制以及更深层次的理论研究做出合理的尝试。     

关节轴承多维试验机的研制

由于装配之前需要对关节轴承进行跑合试验,研制了一种关节轴承多维跑合试验机。通过机构分析,该试验机可以实现三个移动方向的力加载以及三个旋转方向的摆动控制。基于刚体运动学理论,借助数学几何解析法分析了球面并联机构的运动学特性。最后通过跑合试验,验证了该多维试验机可以满足相应的性能指标,能够为关节轴承的性能预测提供可靠试验依据。     

UP344剖分自润滑关节轴承的研制

介绍剖分自润滑关节轴承的性能特点、主要技术参数、材料及润滑机理 ,并详细叙述了固体润滑材料的加工工艺过程。附图 1幅     

关节轴承固体润滑处理工艺

介绍一种关节轴承固体润滑处理技术,制备的固体润滑膜以无机盐和活性金属离子为黏结剂,提高了膜层的耐压强度和耐温性能;以石墨和二硫化钼复合材料为润滑剂,提高了关节轴承在不同工况条件下的承载能力和润滑性。经固体润滑处理的轴承内圈外表面润滑膜层均匀、外观细致,实际使用效果良好。经检测,形成的固体润滑膜与金属基体有较强的结合力,在特殊工况条件下能够满足承载和润滑性能的要求。     

考虑关节固体润滑的在轨装配机械臂振动特性及优化控制

面向大型空间结构在轨装配任务的空间机械臂对末端动态性能有很高要求。基于半物理仿真试验修正关节接触力，建立了考虑固体润滑特性的含关节轴向尺寸和间隙的机械臂动力学模型。通过仿真研究机械臂在不同结构参数与工况参数时重力及重力释放下径向振动特性的差异，并针对在轨装配过程中频繁启停的操作需求，分析变负载启停时的振动特性，以改善动态性能为目标，给出了优化控制方法。     

水利工程用镶嵌型自润滑关节轴承的设计原则

介绍了水利工程闸门用镶嵌型自润滑关节轴承的结构、材料和固体润滑剂的选用、安全系数的计算，密封结构及润滑方式。     

高速电主轴油雾润滑改为油脂润滑的可行性分析

介绍了电主轴的特点及主要润滑方式,通过油脂润滑电主轴的跑合试验,对比分析跑合过程中轴承的温度变化,从而验证高速电主轴油雾润滑改为油脂润滑的可行性.     

空间遥感仪器摆动轴承的润滑剂研究进展

空间运动部件的长寿命可靠性是空间遥感仪器发展的关键。介绍空间遥感仪器摆动轴承润滑特点和机制,概述固体润滑剂和液体润滑剂各自的优缺点及国内外研究现状,介绍MACs油脂的特点及其应用情况,指出摆动轴承所需润滑剂的发展方向。     

Influence of lubricants on the performance of journal bearings – a review

ABSTRACT

The lubricant properties have a significant influence on the static and dynamic performance characteristics of journal bearing such as load-carrying capability, minimum fluid film thickness, maximum pressure, lubricant flow rate, damping coefficients, stiffness coefficients, etc. The present document reviews the behaviour of various lubricants such as power-law lubricants, couple stress lubricants, micropolar lubricants, ionic liquid lubricants and space lubricants. The influence of these lubricants on the performance of hydrostatic, hydrodynamic and hybrid journal bearings is discussed. An effort is made to develop the understanding to choose the suitable lubricant for journal bearings for different journal bearing configurations. Journal bearings operated with non-Newtonian lubricants have shown better performance compared to Newtonian lubricants. Ionic liquid lubricants have shown high potential in vacuum applications and extreme temperature environment such as in bearings of spacecraft moving mechanical assemblies.     

An analysis of changes in surface topography during running-in of plain bearings

The well-established process of running-in is examined in detail using a variety of machines with different lubrication conditions. A general pattern is seen in which the bearing surface steadily becomes smoother. Galling is then likely to ensue with lubricants of insufficient reactivity but prolonged running is possible with suitable solid lubricants. Using digital computation and a precise relocation technique the sequence of topographic changes can be closely followed in terms of roughness average, bearing area and various other parameters. Both plastic deformation and abrasive wear can be detected from the results, supported by examination with a scanning electron microscope. A practical consequence of these studies is the prediction of optimum concentrations of solid lubricant additives and the selection of suitable load and speed conditions. The effects of journal roughness are also clearly demonstrated.     

铁道车辆滚动轴承外圈故障数值模拟与实验

提出了一种故障轴承的三维建模方法,并采用数值模拟和实验研究相结合的方法分析了352226X2-2RZ型双列圆锥滚子轴承在正常状态和外圈剥离故障状态时的故障特征频率。首先,利用三维实体建模软件Solidworks建立了正常状态和外圈剥离故障状态的轴承模型;然后,将模型导入ADAMS中添加约束和驱动,并对两种模型进行动力学仿真分析;最后,利用轮对跑合实验台对故障轴承进行试验测试分析,试验结果与仿真结果十分吻合。研究结果证明了所提出的建模和仿真方法的正确性。     

欠驱动冗余度机械臂的动态自重构

分析了欠驱动冗余度机械臂不同机构模式下运动学模型及动力学模型之间的关系,给出了欠驱动机械臂工作于全驱动模式下的动力学操作性度量指标。提出了一种欠驱动机械臂工作在欠驱动模式时的基于非线性控制技术的自运动控制方法,利用少维数的控制输入实现了机械臂的多维关节空间的运动控制,使欠驱动冗余度机械臂能完成自运动流形控制。提出一种动态提高欠驱动冗余度机械臂工作于全驱动模式时的操作性能的方法,通过有两个被动关节的平面四关节欠驱动机械臂进行了仿真验证。     

Self-lubricating materials for plain bearings

Performance in plain bearing applications of commercially available self-lubricating materials, including ptfe and other plastics and metals containing solid lubricants, is described. They are most useful as either dry bearings or bearings in marginally lubricated situations. Some specific applications are included     

Solid-lubricated ball bearings for use in a vacuum — state-of-the-art

The tribological responses of solid-lubricated ball bearings for vacuum use are described with reference to their friction torque, wear life, performance at high temperatures and high loads, effects of bearing materials other than steel, outgassing, dust generation and cost reduction, based (in part) on the materials offered by Japanese bearing manufacturers. In view of their outgassing and dust-generation characteristics, solid lubricants applied so far are not satisfactory. A new generation of fluorinated-polymer-lubricated bearings provides low contamination properties and can be used in air as well as in vacuum.     

Analysis of hydrodynamic journal bearings having non-Newtonian lubricants

Commercial lubricants, due to the presence of different types of additives, behave like non-Newtonian fluids. The effect of this nonlinear behaviour on the performance characteristics of finite-width journal bearings is investigated using the Eyring model for the shear stress and shear strain rate. the finite element method using Galerkin's technique has been used to solve the momentum equations and the continuity equation in cylindrical coordinates, representing the flow field in the clearance space of a journal bearing system using Newtonian fluids; the non-Newtonian effect is introduced by modifying the viscosity term for the model in each iteration. The results of static performance characteristics for finite-width journal bearings having non-Newtonian lubricants have been obtained.     

Friction of Undulated Surfaces Coated with MoS2 by Pulsed Laser Deposition

Solid lubricants such as molybdenum disulfide can provide very low friction, but their effectiveness especially in the geometrically constrained sliding pairs is limited by plowing of coated surfaces by wear particles. Even in the presence of solid lubricants wear particles cause higher friction by plowing the interface. To minimize plowing, undulated surfaces with microgrooves perpendicular to the sliding direction can be used to trap wear particles. Smooth and undulated stainless steel surfaces were coated with molybdenum disulfide by pulsed laser deposition (PLD) and friction tested. Under identical test conditions, the friction coefficient of coated undulated surfaces is between 20–40 percent lower than that of coated smooth surfaces. The friction coefficient of undulated uncoated surfaces is about 100–350 percent less than that of smooth uncoated surfaces. Moreover, the entrapment of wear particles at the interfaces of geometrically constrained bearings may lead to seizure even when bearing surfaces are coated with solid lubricants. The use of undulated surf aces on these sliding systems has shown improved operating time and a reduced maintenance cycle.