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Theoretical Substantiation of the Initiation and Direction of Crack Development under Impact Loading of the Elastomer Surface by Solid Particles 弹性体表面固体颗粒冲击载荷下裂纹萌生及发展方向的理论依据
IF 0.7 4区 工程技术 Q4 ENGINEERING, MECHANICAL Pub Date : 2023-06-22 DOI: 10.3103/S1068366623010063
V. G. Kopchenkov

A theoretical model of the formation of the stress-strain state in elastomers under the action of a concentrated load is considered. Experimental studies were carried out using the polarization-optical method. As a sample, transparent L-83 polyurethane with physical and mechanical characteristics corresponding to typical rubbers was used. It is shown that the stress-strain state of the surface layer calculated as a result of the theoretical solution of the mathematical model coincides with the experimental data. When loading, zones of compressive and tensile stresses are created. The magnitude of the tensile stress determines the likelihood of surface destruction (tearing). Simulation of an oblique impact confirmed the qualitative picture of the stress-strain state in elastomers under the action of a concentrated load. A theoretical study made it possible to establish that the potential energy of deformation is distributed over the depth of the surface layer in inverse proportion to the square of the distance from the point of application of the force, i.e., the point of contact of the solid particle with the surface of the elastomer. This makes it possible to mathematically calculate the level and distribution of energy dissipation in the wear volume of the surface layer. Theoretical and practical studies have shown that in the practical use of elastomer linings, it is recommended to install them at an angle close to 90° to the direction of solids flow.

建立了弹性体在集中载荷作用下应力-应变状态形成的理论模型。采用偏振光学方法进行了实验研究。以具有典型橡胶物理力学特性的透明L-83聚氨酯为样品。结果表明,由数学模型的理论解计算得到的表层应力-应变状态与实验数据吻合。加载时,会产生压应力和拉应力区域。拉伸应力的大小决定了表面破坏(撕裂)的可能性。斜向冲击的模拟证实了弹性体在集中载荷作用下应力-应变状态的定性图像。一项理论研究使得有可能确定变形势能分布在表层的深度上,与施力点(即固体颗粒与弹性体表面的接触点)距离的平方成反比。这使得用数学方法计算表面层磨损体积中能量耗散的水平和分布成为可能。理论和实践研究表明,在实际使用弹性体衬里时,建议与固体流动方向成接近90°的夹角安装。
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引用次数: 0
Synergism and Antagonism of Anti-Wear Additives as a Method of Confirming the Mechanism of Their Action 抗磨添加剂的增效和拮抗作用及其作用机理的研究
IF 0.7 4区 工程技术 Q4 ENGINEERING, MECHANICAL Pub Date : 2023-06-22 DOI: 10.3103/S1068366623010099
G. F. Pavelko

Abstract

The effect of 2,2,6,6-tetramethylpiperidine (TMP), 2,6-di-tert-butyl-4-methylphenol (DTBMP), para-cumylphenol (PCP), 2,2,6,6-tetramethylpiperidine-1-oxyl (TMPO), and dicumyl peroxide (DCP) on the anti-wear properties of dodecanethiol (DdSH), didodecyl disulfide (Dd2S2), and dibutyl disulfide (Bu2S2) in a solution of purified Vaseline oil (PVO) has been investigated. The anti-wear properties of 23 two-component compositions of additives from 28 possible combinations were studied. A rule was proposed: synergy is when the effectiveness of a mixture of additives is greater than the average result of the sum of anti-wear efficiencies of each component separately, and antagonism is when the effectiveness of a mixture of additives is less than the average result of the sum of anti-wear efficiencies of each component separately. The practical significance of the proposed method for studying two-component additives is that it can be used to confirm or refute the mechanism of action of additives.

摘要研究了2,2,6,6-四甲基哌啶(TMP)、2,6-二叔丁基-4-甲基苯酚(DTBMP)、对五甲基苯酚(PCP)、2,2,6,6-四甲基哌啶-1-氧基(TMPO)和过氧化二氨基(DCP)对十二烷基硫醇(DdSH)、二十二烷基二硫(Dd2S2)和二丁二硫(Bu2S2)在纯化凡士林油(PVO)溶液中的抗磨性能的影响。研究了23种双组分添加剂组合的抗磨性能。提出了一个规律:当混合添加剂的有效性大于各组分单独抗磨效率总和的平均结果时,是协同的;当混合添加剂的有效性小于各组分单独抗磨效率总和的平均结果时,是拮抗的。所提出的双组分添加剂研究方法的实际意义在于,它可以用来证实或反驳添加剂的作用机理。
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引用次数: 0
Evaluation of Dynamic Parameters and Improvement of Wear Resistance of Involute Gears when Using Film-Forming Lubricants 成膜润滑剂对渐开线齿轮动态参数的评价及其耐磨性的提高
IF 0.7 4区 工程技术 Q4 ENGINEERING, MECHANICAL Pub Date : 2023-06-22 DOI: 10.3103/S1068366623010105
S. A. Polyakov, L. I. Kuksenova, E. M. Kuleshova, A. V. Medovshchikov

Abstract

The article describes the problems of existing methods for assessing the durability of involute gears (IGs) associated with determining the maximum permissible wear and predicting the occurrence of sudden failure. The relationship of dynamic indicators with wear processes in IGs is described, which makes it possible to predict resource limitation by the nature of the growth of the dynamic coefficient due to the increase in the probability of jamming. The results of the analysis of the amplitude-frequency response of the transmission by the fast Fourier transform method are presented, which allowed us not only to evaluate the dynamism of the transmission with different lubricants, but also to rank these materials by their extreme pressure action depending on the magnitude of the loading moment, at a given limit value of the dynamic coefficient. It is shown that as the antifriction properties of the lubricant increase, the growth of the dynamism coefficient decreases as the loading moment increases (when using a film-forming additive, the limiting value of the dynamism coefficient is reached at a loading torque of 2.47 N m, and in the case of using pure synthetic oil, the limiting value of the dynamism coefficient is reached at a loading torque of 2.39 N m), this in turn leads to an increase in the maximum permissible wear and to an increase in the resource according to the wear criterion (in the case of using synthetic oil with a film-forming additive, the IG resource is 10–11 times higher than in the case of using pure synthetic oil).The dependence of the amplitude of the torque oscillations on the high-speed shaft of the IG transmission on the type of lubricant is revealed. Analytical dependences of the dynamic coefficient on the load for different lubricants are obtained. The dependence of the wear limit on the type of lubricant is proposed. A new method of predicting the resource of an IG is proposed taking into account the growth of the dynamic coefficient.

摘要:本文描述了现有的渐开线齿轮(IGs)耐久性评估方法在确定最大允许磨损和预测突然失效发生方面存在的问题。描述了IGs中动态指标与磨损过程的关系,通过动态系数由于卡阻概率的增加而增长的性质来预测资源限制。采用快速傅立叶变换方法对变速器的幅频响应进行了分析,这不仅使我们能够评估不同润滑剂下变速器的动态特性,而且还可以在给定的动态系数极限值下,根据加载力矩的大小对这些材料的极端压力作用进行排序。结果表明:随着润滑油抗磨性能的提高,动力系数的增长随着加载力矩的增加而减小(当使用成膜添加剂时,动力系数的极限值在加载扭矩为2.47 N m时达到,而使用纯合成油时,动力系数的极限值在加载扭矩为2.39 N m时达到);这反过来又会导致最大允许磨损的增加,并根据磨损标准增加资源(在使用含成膜添加剂的合成油的情况下,IG资源比使用纯合成油的情况高10-11倍)。揭示了齿轮传动高速轴转矩振荡幅值与润滑油类型的关系。得到了不同润滑剂下动力系数随载荷的解析关系。提出了磨损极限与润滑剂类型的关系。提出了一种考虑动态系数增长的预测IG资源的新方法。
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引用次数: 0
Refinement of Piston Friction Parameters in a Smooth Barrel 光滑枪管中活塞摩擦参数的细化
IF 0.7 4区 工程技术 Q4 ENGINEERING, MECHANICAL Pub Date : 2023-06-22 DOI: 10.3103/S1068366623010130
A. D. Sidorov, V. A. Burakov, V. D. Zorin, A. S. D’yachkovskiy, E. Yu. Stepanov

Abstract

This article describes fine tuning of wear diagnostics of a laboratory smooth barrel with a length of 5 m and diameter of 30 mm during tests. The devices are developed for measurements of internal diameter and force of pulling a piston prototype through the entire barrel length. An analog–digital instrument for measurement of internal diameter allows one to detect and to measure defects of arbitrary deformed barrel. The dimensions of the sensors used in the device allow us to scale it up for measurements of barrel of both lower and higher diameter. The device of force measurements allows us to estimate the friction parameters before experiments to clarify the mathematical model of gas dynamic processes accompanying the shot and to adjust loading conditions, if necessary. It has been demonstrated that their use allows us to estimate wear and to diagnose the state of the barrel system. Significant broadening of bore on the side of the breech end of the barrel has been detected. There is a correlation of measured data from both instruments. A ballistic experiment has been carried out using the updated measuring and recording complex. On the basis of the results the friction parameters of the piston–barrel couple obtained before the experiments have been accounted in the mathematical model of gas dynamic processes. This has allowed us to reduce the number of matching parameters upon simulation and to perform more accurate analysis of gas dynamic processes accompanying a shot with plotting respective time dependences of piston pressure and speed as well as distribution of maximum gas temperatures and pressure along the barrel length. Thus, the coefficient of the law of gunpowder burning has increased by 10%.

摘要:本文介绍了长5 m、直径30 mm的实验室光滑桶在试验过程中磨损诊断的微调。该装置用于测量活塞原型在整个筒体长度内的内径和拉力。一种测量内径的模拟-数字仪器可以检测和测量任意变形桶的缺陷。设备中使用的传感器的尺寸允许我们将其按比例放大,以测量更低和更高直径的桶。力测量装置允许我们在实验前估计摩擦参数,以澄清伴随射击的气体动力学过程的数学模型,并在必要时调整加载条件。已经证明,它们的使用使我们能够估计磨损和诊断桶系统的状态。已发现枪管后端侧膛显着变宽。两种仪器的测量数据有相关性。利用更新后的测量和记录装置进行了弹道试验。在此基础上,将实验前得到的活塞-筒副的摩擦参数纳入气体动力学过程的数学模型。这使我们能够减少模拟时匹配参数的数量,并对伴随射击的气体动态过程进行更准确的分析,绘制活塞压力和速度的各自时间依赖性,以及最大气体温度和压力沿枪管长度的分布。因此,火药燃烧规律的系数提高了10%。
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引用次数: 0
Tribotechnical Characteristics of Lubricant under Conditions of High Temperatures 高温条件下润滑剂的摩擦学特性
IF 0.7 4区 工程技术 Q4 ENGINEERING, MECHANICAL Pub Date : 2023-06-22 DOI: 10.3103/S106836662301004X
O. Yu. Elagina, A. G. Buklakov, S. I. Dumansky

This article discusses the issues of maintaining operability of hinged friction joints operating at 500°C. The object of study is the hinged joint of a pipe dryer operating contact loads in the friction joint up to 100 kN and operation temperatures in the range from 200 to 500°C. The studies have been performed with WOLFRAKOTE TOP FLUID high temperature lubricant comprised of solid lubricants suspended in base mineral oil. The experimental results of the lubricating composition upon heating in mold have demonstrated that burn up of the liquid component is intensified at 450°C being accompanied by transfer of lubricating medium into powdered form. Assessment of changes in tribological properties of high temperature lubricant in various aggregate states has demonstrated that heating and transfer of lubricant from liquid to solid state at low contact loads and velocities does not impair its tribotechnical properties. However, the increase in load and velocity parameters causes sharp increase in friction forces with the use of lubricating medium in powdered form. Based on the performed studies recommendations are presented aimed at improving the operability of hinged joints operating at higher temperatures.

本文讨论了在500°C下保持铰接摩擦接头的可操作性的问题。研究的对象是一种管式干燥机的铰链接头,其摩擦接头接触载荷高达100kn,工作温度为200 ~ 500℃。该研究是用悬浮在基础矿物油中的固体润滑剂组成的WOLFRAKOTE TOP FLUID高温润滑剂进行的。在模具中加热润滑组合物的实验结果表明,液体成分的燃烧在450°C时加剧,同时伴随着润滑介质转化为粉末形式。对不同集合体状态下高温润滑剂摩擦学性能变化的评估表明,在低接触载荷和低接触速度下,润滑剂从液体到固体的加热和转移不会影响其摩擦学性能。然而,当使用粉末状润滑介质时,载荷和速度参数的增加会导致摩擦力的急剧增加。根据所进行的研究,提出了旨在提高铰链接头在高温下工作的可操作性的建议。
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引用次数: 0
Influence of the Fiber Bedding Direction on the Fiber Composite Wear 纤维层理方向对纤维复合材料磨损的影响
IF 0.7 4区 工程技术 Q4 ENGINEERING, MECHANICAL Pub Date : 2023-06-22 DOI: 10.3103/S1068366623010129
A. G. Shpenev, P. O. Bukovskiy

Abstract

The fibrous composite wear rate dependence on the angle between the sliding direction and the direction of the fibers on the friction surface, when fibers in the material are parallel to the friction surface was studied. For this purpose, an experiment was carried out on the wear of a composite material sample based on carbon fiber and a carbon matrix in the form of a disc with a ring-shaped counterbody made of silicon carbide ceramics. The structure of the composite made of carbon twill weave forms on the friction surface areas with fibers oriented parallel to each other and the surface of the material. Setting up the experiment according to the “ring–disk” scheme allows one to obtain a different angle between the direction of the fibers and the direction of sliding in one test. Based on the results of the friction surface relief study after the tests, the relative wear rate of the surface areas, which are characterized by different directions of the fibers, is determined. It was found that areas with fibers directed at an acute angle to the friction direction have greater wear resistance, and fibers located at a right angle to the direction of sliding are more susceptible to destruction during wear. A wear process model of an individual fiber up to its complete destruction is constructed. A phenomenological criterion for the destruction of an individual fiber is proposed, which makes it possible to estimate the effect of the angle between the direction of the fiber and the direction of sliding on the destruction of the fiber. An algorithm for determining the coefficients included in the proposed wear model, based on a limited number of tribological tests, is proposed.

摘要:研究了当纤维与摩擦面平行时,纤维复合材料的磨损率与纤维在摩擦面上的滑动方向与纤维方向夹角的关系。为此,以碳化硅陶瓷为材料,对碳纤维与碳基体的圆盘状复合材料样品进行了磨损试验。碳斜纹织物复合材料的结构形成于摩擦表面,纤维取向与材料表面平行。根据“环盘”方案进行实验,可以在一次测试中获得纤维方向与滑动方向之间的不同角度。根据试验后的摩擦面起伏研究结果,确定了不同纤维方向的摩擦面相对磨损率。研究发现,纤维与摩擦方向成锐角的区域耐磨性更强,与滑动方向成直角的纤维在磨损过程中更容易被破坏。建立了单个纤维直至其完全破坏的磨损过程模型。提出了一种单纤维破坏的现象学判据,可以估计纤维方向与滑动方向之间的夹角对纤维破坏的影响。提出了一种基于有限数量的摩擦学试验来确定所提出的磨损模型中包含的系数的算法。
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引用次数: 0
Electrokinetic Phenomena in Near Surface Layers of Metal Polymer Friction Elements 金属聚合物摩擦元件近表层的电动力学现象
IF 0.7 4区 工程技术 Q4 ENGINEERING, MECHANICAL Pub Date : 2023-03-13 DOI: 10.3103/S1068366622060058
A. Kh. Janahmadov

Abstract

This article discusses the near surface layers of polymer lining of a spot-type disk brake and proposes the algorithm of nonequilibrium thermodynamics, which contains thermal conductivity and electrokinetic phenomena in near surface layers of polymer lining. The possibility of application of nonequilibrium dynamics with linear regimes in tribocouplings of friction devices has been substantiated and the electrokinetic effect has been revealed. It has been demonstrated that due to the cross effect with temperature gradients there exist two equilibrium states for metal friction elements: steady state surface temperature and thermal stabilization state. For the polymer lining the equilibrium state is understood as burnout of binding components from its near surface layer with formation of fluid islands. The relations of parameters have been formed equaling the Onsager and Saxen relations, which allows one to determine the parameters by calculations. The electrokinetic effect can be used for removal of moisture from the friction surface of brakes, thus providing stability of the friction coefficient.

摘要:本文讨论了点式盘式制动器聚合物衬里近面层,提出了包含聚合物衬里近面层导热现象和电动力学现象的非平衡态热力学算法。证明了非平衡线性动力学在摩擦装置摩擦联轴器中应用的可能性,揭示了电动力学效应。结果表明,由于温度梯度的交叉效应,金属摩擦元件存在两种平衡状态:表面温度稳态和热稳定状态。对于聚合物衬里,平衡状态被理解为结合组分从其近表层燃尽并形成流体岛。建立了类似于Onsager和Saxen关系的参数关系,从而可以通过计算确定参数。电动效应可用于去除制动器摩擦表面的水分,从而提供摩擦系数的稳定性。
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引用次数: 0
Tribological Properties of Antifriction Molybdenum Disulfide Coatings under Extreme Conditions 极端条件下抗磨二硫化钼涂层的摩擦学性能
IF 0.7 4区 工程技术 Q4 ENGINEERING, MECHANICAL Pub Date : 2023-03-13 DOI: 10.3103/S1068366622060125
M. V. Prozhega, E. O. Reschikov, E. O. Konstantinov, M. M. Kharkov, F. A. Grigoriev

The tribological properties under extreme conditions, structure, and chemical composition of antifriction coatings based on molybdenum disulfide deposited by magnetron deposition and suspension spraying with various types of a film former onto the surface of samples made of 12Kh18N10T stainless steel are studied. Tribological reciprocating movement tests in accordance with the ASTM G133 standard are carried out under reciprocating movement of a ball made of ShKh15 steel with a diameter of 6.35 mm in vacuum at the temperature of the samples of 250°C. The coefficient of friction and lifetime of the coatings under extreme operating conditions are determined. Suspension deposited coatings show a coefficient of friction of 0.046–0.049, and the magnetron deposited coating of 0.061. The maximum service life of the suspension deposited coatings is 19.7–21.8 h, and of the magnetron deposited coating, 22.7 h.

研究了在12Kh18N10T不锈钢表面采用磁控沉积和悬浮喷涂两种不同成膜剂制备的二硫化钼耐磨涂层在极端条件下的摩擦学性能、结构和化学成分。按照ASTM G133标准,用直径为6.35 mm的ShKh15钢制成的球在真空中往复运动,试样温度为250℃,进行摩擦往复运动试验。测定了涂层在极端工况下的摩擦系数和寿命。悬浮沉积涂层的摩擦系数为0.046 ~ 0.049,磁控管沉积涂层的摩擦系数为0.061。悬浮沉积涂层的最大使用寿命为19.7 ~ 21.8 h,磁控管沉积涂层的最大使用寿命为22.7 h。
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引用次数: 0
Friction and Wear of Asbestos-Free Brake Friction Materials 无石棉刹车摩擦材料的摩擦和磨损
IF 0.7 4区 工程技术 Q4 ENGINEERING, MECHANICAL Pub Date : 2023-03-13 DOI: 10.3103/S1068366622060101
N. G. Meliksetyan, N. K. Myshkin, S. G. Agbalyan, G. N. Meliksetyan

The results of tribological studies of various asbestos-free brake friction materials from leading manufacturers are presented. Two main aspects of the effect of the thermal conditions on the friction and wear characteristics of the selected materials are established: a change in the physical and mechanical properties at a low thermal load of the friction contact and changes due to various structural transformations and mechanochemical processes of the surface layers at a high thermal load of the friction contact. It is shown that high-temperature friction of frictional asbestos-free polymeric materials proceeds in a multistage mode, accompanied by pyrolysis of volatile products, binder destruction, degradation of the reinforcing element, and carbonization of the friction surface, which are constant factors. The materials under study are capable of forming a frictional transfer film on the counterbody friction surface in the form of a monolithic layer or separate transferred fragments oriented along the sliding direction. The developed materials form a film on the counterbody surface at relatively high temperatures, in the region of maximum friction values. It is established that the mechanism of high-temperature destruction of the surface layers of asbestos-free brake friction materials is characterized by the accumulation of damage in the subsurface layer and the wear process is most fully explained by fatigue peeling.

介绍了主要制造商对各种无石棉制动摩擦材料的摩擦学研究结果。建立了热条件对所选材料摩擦磨损特性影响的两个主要方面:摩擦接触低热负荷时物理机械性能的变化以及摩擦接触高热负荷时表层各种结构转变和机械化学过程的变化。结果表明:无石棉摩擦高分子材料的高温摩擦是一个多阶段的过程,伴随着挥发产物的热解、粘结剂的破坏、增强元素的降解和摩擦表面的碳化,这些都是恒定的因素。所研究的材料能够在反摩擦表面形成摩擦转移膜,其形式为单片层或沿滑动方向定向的分离转移碎片。在相对较高的温度下,在最大摩擦值区域内,所开发的材料在对偶体表面形成薄膜。提出了无石棉制动摩擦材料表层高温破坏的机理是以亚表层损伤的累积为特征,疲劳剥落是其磨损过程的最充分解释。
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引用次数: 2
Tapered Roller Bearing Rib-Roller End Interaction at Hydrodynamic Contact 圆锥滚子轴承肋-滚子端部流体动力接触的相互作用
IF 0.7 4区 工程技术 Q4 ENGINEERING, MECHANICAL Pub Date : 2023-03-13 DOI: 10.3103/S106836662206006X
I. M. Klebanov, A. M. Brazhnikova, K. A. Polyakov

Abstract

Wear of the contact surfaces is an important characteristic of rib-roller end interaction of roller bearings. The purpose of this study was to develop effective methods for calculating the wear rate of these surfaces under alternating dynamic loads. In wear rate calculations of bearing parts, as a rule, Archard’s law is used since it has been verified in hydrodynamic friction testing of bearing steels. In the paper, based on this law, a direct step-by-step wear rate calculation method for rib-roller end contact at variable loads and sliding speeds is developed. According to it, normal force, sliding velocity, and contact oil film thickness are determined in bearing dynamic modeling, and the finite element method is used to calculate contact pressure fields. A multi-mass bearing dynamic model includes a contact friction model, which allows an adequate description of hydrodynamic contact behavior of solid bodies. Using the bearing life dependence on the oil film parameter and experimentally measured steel bearing wear rates, the dependence of wear coefficient on the oil film parameter is obtained. The direct calculation method involves many computations, which makes the influence of individual factors on wear rate non-obvious. In this regard, a method of wear rate calculation with averaged parameters is also proposed. Using these two methods, rib-roller end wear calculations for a double-row tapered roller bearing are implemented. The spherical shape of the roller end and conical, toroidal convex, and concave shapes of the rib are considered. Comparison of wear rates obtained by the two methods confirms the acceptable accuracy of calculations with averaged parameters. The results in particular demonstrate that a toroidal concave rib surface allows reducing the wear rate up to three times in comparison with the tapered surface.

接触面磨损是滚子轴承肋-滚子端部相互作用的一个重要特征。本研究的目的是开发有效的方法来计算这些表面在交变动态载荷下的磨损率。在轴承零件磨损率的计算中,一般采用阿卡德定律,因为它已在轴承钢的水动力摩擦试验中得到验证。本文在此基础上,提出了一种变载荷、变滑动速度下肋辊端部接触的直接步进磨损率计算方法。在此基础上,在轴承动力学建模中确定了法向力、滑动速度和接触油膜厚度,并采用有限元法计算了接触压力场。多质量轴承动力学模型包括接触摩擦模型,该模型可以充分描述固体的流体动力接触行为。利用轴承寿命对油膜参数的依赖关系和实验测量的钢轴承磨损率,得到了磨损系数对油膜参数的依赖关系。直接计算法计算量大,个别因素对磨损率的影响不明显。在此基础上,提出了一种基于平均参数的磨损率计算方法。利用这两种方法,实现了双列圆锥滚子轴承肋-滚子端部磨损的计算。考虑了滚轮端部的球形形状和肋部的锥形、环形凸形和凹形。比较两种方法得到的磨损率,证实了平均参数计算的精度是可以接受的。结果特别表明,与锥形表面相比,环形凹肋表面可以将磨损率降低三倍。
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引用次数: 1
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Journal of Friction and Wear
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