锌基合金主螺母的研究

分析了摩擦压力机主螺母受力情况，确定了使用性能指标，并成功地研制了一种锌合金主螺母材料。其耐磨性优于ＺＱＡ１９－４，ＺＱＳｎ６－６－３。在使用过程中尺寸稳定性和冲击疲劳性能良好。使用寿命和铜合金相比提高１倍以上，可取得明显的经济效益和社会效益。     

影响离心铸造铜合金质量之要因

本文着重介绍了ＺＣｕＳｎ５Ｚｎ５Ｐｂ５、（ＺＣｕＳｎ６Ｚｎ６Ｐｂ３）、ＺＣｕＳｎ１０Ｐ１、ＺＣｕＡｌ１０Ｆｅ３、ＺＣｕＺｎ２５Ａ１６Ｆｅ３Ｍｎ３、ＺＣｕＺｎ３８Ｐｂ２Ｍｎ２、美国材料Ｔ—１０５、Ｔ—１１５等铜合金采用离心铸造时，如何控制铸件质量等方面的实践经验和主要工艺方法。     

锌铝合金和铝青铜摩擦磨损特性的研究

研究了锌铝合金ＺＡ－Ｓｉ和铝青铜ＺＣｕＡｌ１０Ｆｅ３在２０号机油润滑条件下的摩擦磨损特性。结果表明：在一定的条件下，ＺＡ－Ｓｉ合金的耐磨性能和磨合性能均明显优于ＺＣｕＡｌ１０Ｆｅ３合金；二种合金的磨损机制主要是犁削，辗压和粘着，ＺＡ－Ｓｉ合金的粘着磨损具有延缓性和失效性的双重特性。     

锌铝金（ZA27）润滑时摩擦损特性研究

本研究ＺＡ２７合金在润滑下的摩擦磨损特性。提出在油润滑下ＺＡ２７合金同材质摩擦时，磨损特点是边界润滑摩擦；其与４５钠配副摩擦时，摩擦特点主要的犁削。根据损失重分析得出；ＺＡ２７合金的润滑工况下是一种良好的减摩材料。     

硅线石颗粒／LY12复合材料摩擦磨损性能研究

采用搅融混合－半固态挤压方法，复合成形硅线石颗粒／ＬＹ１２复合材料，并对其进行了摩擦学性能测定。通过对摩擦形貌的扫描电镜、Ｘ射线分析，研究了材料的摩擦磨损机理。同ＺＱＳｎ６－６－３材料摩擦学性能相比较，表明硅线石颗粒／ＬＹ１２复合材料具有广泛的应用前景。     

SiC颗粒增强ZA27基复合材料的摩擦磨损性能

用环－块式磨损试验机研究了同一体积分数（１０ｖｏｌ％）、５￣８０μｍ粒径ＳｉＣ颗粒增强ＺＡ２７基复合材料的摩擦磨损特性。发现复合材料的耐磨性为未增强基体的１５倍以上；中等尺寸（１０，２０μｍ）的颗粒对耐磨性具有最佳增强效果。     

ZA27合金熔炼

１ＺＡ２７合金的化学成分及机械性能表１ＺＡ２７合金的化学成分主要成分％杂质含量＜％ＡｌＣｕＭｇＺｎＦｅＰｂＣｄＳｎ２５－２８２．０－２．５０．０１－０．０２余量０．１００．００４０．００３０．００２表２ＺＡ２７合金的物理性能σｂＭＰａσａＭＰａδｓ％ＨＢ密度ｇ／３８０－４４１３６５－３７２２．５－１１９０－１２５５．０２材料准备表３炉料合金元素的标准名称牌号标准铝锭Ａ１９９７或Ａ１９９６ＧＢ１１９６－８３锌锭Ｚｎ－０或Ｚｎ－１ＧＢ４７０－８３镁锭Ｍｇ９９．９５ＧＢ３４９９－８３铜Ｃｕ－１ＧＢ４６６－８２中间合金ＡｌＣｕ－５０ＧＢ８７５３５－８８ＺｎＣｌ２二级以上ＧＢ１６２５－７９变质剂自制３工装准备燃油坩埚炉一台；ＷＲＮ－１２０ＥＵ－２测温仪一台；天平一架；其它炉炼工具自制。４熔炼及熔炼过程控制ＺｎＡｌ２７合金的熔炼与传统的有色合金熔炼过程无大的区别，其基本过程大致分为：准备（炉料、设备和工具）、加料、加热熔化、精炼变质、炉前检验和浇注六大步骤，较传统合金熔炼多了一道变质处理工序。其中熔炼过程温度的控制，精炼剂的脱水，合金的变质处理，回炉料的加入量等对合金的机械性能起着至关重要的作用。而整个熔炼过程则紧紧围绕...     

挤制QAl10—3—1.5铝青铜管调质前后的性能组织分析

通过对挤制ＱＡｌ１０－３－１．５铝青铜管调质前后力学性能和显微组织的分析,论证了军用轴承保持架使用挤制ＱＡｌ１０－３－１．５铝青铜管制造时,必须进行调质处理。     

ZW－1型材料蜗轮研制

采用正交试验方法筛选出一种聚合物基复合蜗轮材料──ＺＷ－Ｉ型蜗轮材料；与ＺＱＳｎ１０－Ｉ型铸锡青铜蜗轮以及ＺｎＡＩＣｕＭｎ型锌铝合金蜗轮相比，ＺＷ－１型材料蜗轮在传动效率、热功率、耐磨寿命、抗胶合性以及成本等方面具有明显的优越性。     

ZQA19－4阀杆螺母以ZCuZn28A14Fe3Mn3替代的试验

介绍了阀杆螺母材料ＺＱＡ１９－４以ＺＣｕＺｎ２８Ａ１４Ｆｅ３Ｍｎ３替代的试验过程。论述了替代材料的工艺性能、生产成本及使用性能。总结了替代材料在熔炼操作、粘渣处理及控制元素含量方面的经验。     

Evaluation of Ball-Bearing Performance in Liquid Hydrogen at DN Values to 1.6 Million

Experimental data were obtained in liquid hydrogen (?423 F) on two series of 40-mm-bore ball bearings utilizing various retainer materials. Effects of diametral clearance and retainer material on limiting DN value (product of bearing bore in mm and shaft speed in rpm) were investigated at thrust loads to 500 lb and at speeds to 41,200 rpm. An analysis was made to determine the effect of ball size and race curvatures on the heat generated in bearings of both series as a result of ball spin. The results, supported experimentally, indicate that higher limiting DN values at a specific thrust load could be obtained with an extremely light series (1908) bearing with open-race curvatures than with a light series (108) bearing. Successful operation to a DN value of 1.6 million was obtained with 1908 bearings (at 110 lb thrust load) using two different retainer materials. The glass-fiber-filled PTFE (polytetrafluoroethylene) retainer exhibited much less wear than the MoS₂-filled phenolic retainer at these test conditions.     

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.     

Torque Variations in Instrument Ball Bearings

Disturbances in the torques and motions in angular contact instrument ball bearing pairs are described and analyzed. Among others, a motion of the ball retainer, analogous to dry friction whirl, is attributed to frictional coupling between balls and retainer, and an interaction between bearings, resulting in several low frequency perturbations, is explained in terms of ball errors. Experimental confirmation is obtained.     

Oil Exchange Between Ball Bearings and Cotton-Phenolic Bail-Bearing Retainers

Experiments have been performed that determine for the first time the transfer of oil between cotton-phenolic ball-bearing retainers and operating ball bearings. A full retainer exchanges oil with the metal park of the bearing, probably by diffusional mixing. There is no net delivery of oil from the retrainer to the metal parts of the bearing. A partially filled retainer (such as one that has been incompletely impregnated) absorbs oil from the bearing even during operation, this drying the bearing. A fully-impregnated retainer does not deliver any significant amount of additional oil to the metal parts of a poorly lubricated bearing. The retainer will not prevent lubricant degradation and premature bearing failure under the conditions of these experiments.     

深沟球轴承自动装配条件下的结构工艺性

通过对深沟球轴承在自动装配条件下的结构工艺性从定性和定量两个角度进行深入分析,不仅判定深沟球轴承可以实现自动装配,而且指出分球和保持架的上料将是装配自动线设计过程中的两个技术难点。     

Oil Exchange between Ball Bearings and Porous Polyimide Ball Bearing Retainers

The kinetics of the absorption of lubricating oils and moisture from air into porous polyimide, as well as the exchange of oil between porous polyimide retainers and oil baths or operating bearings, have been measured. Oil absorption into porous polyimide is much faster than into cotton-phenotic. Water is absorbed by oil-impregnated polyimide, but little or no oil is lost during the process. Oil is absorbed by air-equilibrated polyimide at a slower rate than by dry polyimide. Porous polyimide is much easier to impregnate with oil than cotton-phenolic, and is also much more tolerant, of storage in air once impregnated. Oil within a porous polyimide ball bearing retainer exchanges slowly with oil in a bath in which the retainer is placed. The exchange is due to diffusion of the oils, and the diffusion coefficient is determined to be 3 × 10^?9 cm²/s for the oils used in these experiments. Oil is exchanged quickly between polyimide retainers and well-lubricated operating bearings. The exchange is faster than a diffusion process, and is probably driven by bearing action. In these experiments, the authors could detect no net gain or loss of oil from the retainer or the bearing parts. Only about one-half of the oil originally supplied to the parts is available to the retainer; the rest remains elsewhere in the bearing.     

基于COSMOS/Simulation的深沟球轴承的接触有限元分析

采用SolidWorks2009建立深沟球轴承三维模型,利用SolidWorks自带的有限元软件COSMOS/Simulation对深沟球轴承进行接触有限元分析,得出了轴承内外圈、滚珠、保持架之间的接触力、应力、应变的变化情况及接触过程中的压力变化情况,为轴承的设计分析提供了一种可行的方法。     

球轴承流体分球装置

简要介绍了当前国内球轴承钢球均分以安装轴承保持架的方法,指出存在的不足,提出了一种新颖的非接触式分球装置,并介绍了其工作原理.     

Evaluation of Ion-Sputtered Molybdenum Disulfide Bearings for Spacecraft Gimbals

High-density, sputtered molybdenum disulfide films (MoS₂) were investigated as lubricants for the next generation of spacecraft gimbal bearings where low torque signatures and long life are required. Low friction in a vacuum environment, virtually no out-gassing, insensitivity to low temperature, and radiation resistance of these lubricant films are valued in such applications. One hundred and twenty five thousand hours of accumulated bearing lest time were obtained on 24 pairs of flight-quality bearings ion-sputtered with three types of advanced MoS₂ films. Life tests were conducted in a vacuum over a simulated duty cycle for a space pay bad gimbal. Optimum retainer and ball material composition were investigated. Comparisons were made with test bearings lubricated with liquid space lubricants.

Self-lubricating PTFE retainers were required for long life, i.e., > 40 million gimbal cycles. Bearings with polyimide retainers, silicon nitride ceramic balls, or steel balls sputtered with MoS₂ film suffered early torque failure, irrespective of the type of race-sputtered MoS₂ film. Failure generally resulted from excess film or retainer debris deposited in the ball track which tended to jam the bearing. Both grease lubricated and the better MoS₂ film lubricated bearings produced long lives, although the torque with liquid lubricants was lower and less irregular.     

Fluid Flow Analysis for Friction Torque around Rolling Element in Ball Bearings

Ball bearings (e.g., deep-groove, angular-contact, and roller bearings) support loads in a rotor system and provide lubrication between the shaft and housing. The deep-groove ball bearings used in a turbopump do not differ significantly from angular-contact ball bearings or the bearings found in other applications. Deep-groove ball bearings consist of rolling elements, an inner raceway, an outer raceway, and a retainer to guide the rolling elements. In ball bearings, the resistive (churning or drag) forces and torques acting on the rolling elements and raceways are affected by the fluid flow rate and direction, as well as the rotational speed. These churning and drag forces and torques affect the internal dissipation or power losses into the bearing, which become very significant for high-speed applications. This study numerically investigated the characteristics of the flow conditions for deep-groove ball bearings, with a particular focus on the friction distribution on the rolling elements. A simple analytical model of the fluid flow inside a ball bearing was developed using a computational analysis, and the flow characteristics at high rotational speeds are presented.