润滑剂对轴承工作性能的影响

从实际工作过程中润滑剂对滚动轴承寿命、摩擦力及运转温度的影响等方面阐述了润滑剂在轴承工作过程中所起到的重要作用。     

清洁度对空气压缩机主机寿命的影响

详细介绍了空气压缩机在维修、装配、保养中就清洁度对主机寿命所产生的影响及注意事项，对提高主机寿命和安全商效运行提供了参考。     

The Effects of Lubricant Rheology on the Performance of Journal Bearings

Experiments have been carried out on a relatively simple journal bearing rig to test the theory that extra load-carrying capacity is generated the elasticity of viscoelastic lubricants. Model lubricants were used. The viscoelastic lubricants were solutions of high-molecular-weight polyisobutene in low-molecular-weight polyisobutene while the inelastic lubricant was low-molecular-weight polyisobutene.

The extra load-carrying capacity has been established. An analysis of the detailed results strongly indicates that the extra benefit of elasticity is much greater than that predicted by existing theory.     

具有良好高低温性能的仪表轴承用润滑油的研制

为使精密仪表轴承在-70～+70℃宽环境温度范围下运转时能保持低摩擦扭矩,具有更好的灵敏度,研制一种新的具有良好高、低温性能的优质润滑油。润滑油的理化性能、润滑性能试验和高、低温启动试验表明,所研制的68#聚醚油具有优良的黏温性、低温流动性以及摩擦学特性,完全满足高精密仪表轴承在宽环境温度范围下的运转要求。     

Effect of Lubricant Non-Newtonian Behavior and Elastic Deformation on the Dynamic Performance of Finite Journal Plastic Bearings

This paper presents a numerical study of the performance of a dynamically loaded finite journal plastic bearing lubricated with a non-Newtonian fluid, taking into account the elastic deformation of the bearing. The non-Newtonian characteristics are adopted in this paper through an equivalent power-law. An expression for a modified Reynolds equation is derived in order to obtain the pressure gradient. Elastic deformation of the bearing surface was estimated in a direction normal to the bearing surface using Boussinesq equations. The film shape was modified accordingly and then iterated with the hydrodynamic pressure distribution in the bearing until a convergent solution was obtained. The Reynolds equation was solved numerically, considering three values of the flow-behavior index (n = 0.6, 1, and 1.2) and a wide range of journal speeds, materials, and clearance ratios. Consequently, the finite perturbation technique was used to determine the eight values of oil film stiffness and damping coefficients. By using the dynamic coefficients, the stability characteristics of the rotor-bearing system and the critical speed were calculated. The results show that increasing the flow-behavior index enhances the rotor-bearing system stability. A considerable destabilizing effect is obtained upon decreasing the elastic deformation coefficient.     

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).     

全陶瓷球轴承油润滑特性及其对服役性能影响规律

相比于金属球轴承,全陶瓷球轴承在极端工况下的服役性能更加突出。为了揭示全陶瓷球轴承油润滑特性,提高全陶瓷球轴承的运转性能与使用寿命,以6208CE氮化硅全陶瓷深沟球轴承为例,对其在油润滑工况下所表现出的摩擦、振动、温升等特性进行试验研究,探讨供油量对全陶瓷球轴承润滑状态的影响,并对试验后的全陶瓷球轴承接触微区表层进行解析。研究发现：全陶瓷球轴承油润滑服役过程中,在某个特定工况下存在一个最佳供油量,使得轴承可实现全膜润滑,从而表现出最好的摩擦、振动、温升等特性;小于最佳供油量时,为乏油状态,轴承接触微区存在油-固混合润滑状态;大于最佳供油量时,过多润滑油液会产生的黏滞阻力;相比于载荷,轴承的转速对最佳供油量的取值具有决定性影响。研究成果对于揭示全陶瓷球轴承油润滑特性,丰富其润滑理论与方法具有一定指导意义。     

Lubricant Life Tests on Ball Bearings for Space Applications

An experimental program has been conducted to compare the effective lives of ball bearings operating in vacuum with various types of MoS₂ solid films, and with a special high vacuum oil, as lubricants. The test bearings were size 205 bearings running at 30 rpm under a ten-pound radial load. Two particular combinations were also evaluated in oscillating motion tests. Torque was used as the criterion for failure. Prior to test the bearings were subjected to a 2100-pound static load to simulate launch loading. The results of these tests showed that most of the solid film-lubricated bearings were effective for the first several hundred hours, then gave high and erratic torque values as the result of debris being formed by wear of the lubricant film. A sodium-silicate bonded solid lubricant film, which contained MoS₂ and graphite, was found to be particularly promising in both rotation and oscillation. One particularly significant result of this work was the finding that the oil-lubricated bearings showed a sudden, large increase in torque after running effectively for about 1400 hours in vacuum. This behavior has often been predicted but has apparently never been observed experimentally, at least for rolling-contact hearings.     

Design of High-Stress Slip Bearings with Liquid Lubricant

The design of slip bearings with liquid lubricant used in airplane engines is analyzed. The advantages and disadvantages of the bearings when used in highly stressed transmissions are considered. Means of improving the bearings by means of new materials are proposed.     

涂层材料特性对滚子轴承润滑性能的影响*

涂层材料被广泛应用于滚子轴承中以改善界面性能和提高疲劳寿命,为了探讨涂层材料性能对滚子轴承润滑性能的影响,基于流体力学与接触力学理论,建立带涂层的有限长线接触弹流润滑模型,探讨不同载荷、速度以及涂层材料特性对油膜压力、油膜厚度的影响。研究表明：随着涂层厚度的增加,硬涂层使得最小油膜厚度先增加后减小,而软涂层轻载时使得最小油膜厚度先减小后增加,重载时最小油膜厚度一直减小;随着速度的增加,出口区二次压力峰值增加,硬涂层尤为明显,并且油膜厚度也增加,油膜平坦区域减小,出口区油膜紧缩值增加。为提高润滑性能,当使用较厚软涂层时应考虑增加滚子凸度量,而使用较厚硬涂层时应考虑减小滚子凸度量。     

脂润滑轴承静置状态下漏油机理及对策

脂润滑轴承在静置状态下的漏油问题一直是一个难题。枯文旨在地润滑脂的分油及基础油在固体壁面的迁移分析,来探求脂润滑轴承润滑剂泄漏机理;同时介绍了在润滑脂中加入氟表面活性剂、改善轴承壁面结构设计两项措施来降低脂润滑轴承在静置状态下的漏油。     

聚四氟乙烯乳液对绿色水基润滑剂摩擦学性能的影响

将聚四氟乙烯乳液作为绿色水基润滑剂的润滑性能改进剂,通过四球试验机和销盘磨损试验机考察了绿色水基润滑剂M与聚四氟乙烯乳液(具有亲水性)复配后的抗磨减摩性能,并分析其作用机制.结果表明:水基润滑剂M与聚四氟乙烯乳液具有良好的协同效应;聚四氟乙烯乳液在摩擦过程中具有良好的抗磨减摩作用,可使绿色水基润滑剂M的承载能力增加41%,磨斑直径减少2.2%;聚四氟乙烯乳液在摩擦过程中可能起到磨屑抛光作用.