共查询到20条相似文献,搜索用时 78 毫秒
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为了提高水压滑靴副的抗倾覆能力,并且更加准确地认识其流动特性,提出了三腔独立支承的新型水压滑靴副结构,研究了其润滑特性比如抗倾覆能力和泄漏等。该结构采用独立阻尼和支承腔室的思路,通过独立刚度调节来增加滑靴副的抗倾覆能力。通过仿真计算与分析,对比了新型滑靴副和普通滑靴副的抗倾覆能力。同时, 综合考虑了水的流动惯性和表面粗糙度等因素,发现水压滑靴副水膜流场的流态可能为紊流,并不完全是纯层流状态,因此流态模型的差异将直接影响泄漏流量的计算结果,进一步影响到设计计算的准确性。研究结果为水压柱塞泵滑靴副的结构设计提供了一定的参考和更加准确的计算思路。 相似文献
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水润滑滑动轴承是高压海水泵关键配对副,由于水介质的弱润滑性,轴承副存在严重的摩擦发热,进而引发热卡滞等问题。考虑轴承接触表面沟槽不同构形,建立了轴承的承载与散热模型,研究沟槽数量和形状对润滑支撑和散热的影响。仿真表明:四沟槽轴承的最大温升为39.14℃,八沟槽轴承的最大温升为24.77℃,两者相差36.7%,随着沟槽数量的增加,轴承散热性能得到优化;随着沟槽数量增加,轴承内表面的最大接触应力和变形量也随之增加,相较于四沟槽轴承,八沟槽轴承的最大接触应力增加了5%,最大变形量上升了12%。因此,综合考虑沟槽结构对轴承整体支撑性能和散热作用的影响,设计双向六沟槽螺旋结构,实现海水泵轴承副内循环冷却。 相似文献
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食品机械加工中的摩擦磨损直接影响着食品安全问题。选用黄豆与316L不锈钢进行配副,采用滑动摩擦磨损试验机,研究干摩擦和水润滑条件对其摩擦学性能的影响。利用光学显微镜、光学三维形貌仪和红外光谱仪对试样的表面形貌、粗糙度和磨损表面成分进行了分析。结果表明:干摩擦条件下,黄豆/316L不锈钢摩擦副的平均摩擦因数波动较小,约为0.24,水润滑条件下其平均摩擦因数达到干摩擦条件下的4.4倍左右,且在摩擦过程中存在反复波动;与干摩擦相比,水润滑条件下不锈钢试样表面的磨痕宽度提高约10%,而黄豆试样表面的磨痕宽度的增加幅度约高达160%;水润滑摩擦过程中不锈钢磨痕表面产生更多黄豆分解的有机物,其磨痕表面的犁沟数量和深度均显著减少,黄豆试样磨痕表面基本没有犁沟;干摩擦条件下黄豆/不锈钢的磨损机制以磨粒磨损为主,而水润滑条件下,黏着磨损显著增加。 相似文献
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Junhui ZHANG Yining SHEN Minyao GAN Qi SU Fei LYU Bing XU Yuan CHEN 《Frontiers of Mechanical Engineering》2022,17(4):48
Well-designed surface textures can improve the tribological properties and the efficiency of the electro-hydrostatic actuator (EHA) pump under high-speed and high-pressure conditions. This study proposes a multi-objective optimization model to obtain the arbitrarily surface textures design of the slipper/swash plate interface for improving the mechanical and volumetric efficiency of the EHA pump. The model is composed of the lubrication film model, the component dynamic model considering the spinning motion, and the multi-objective optimization model. In this way, the arbitrary-shaped surface texture with the best comprehensive effect in the EHA pump is achieved and its positive effects in the EHA pump prototype are verified. Experimental results show a reduction in wear and an improvement in mechanical and volumetric efficiency by 1.4% and 0.8%, respectively, with the textured swash plate compared with the untextured one. 相似文献
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The friction and wear behaviors of polyamide 66 (PA 66) and rubber-filled PA 66 (PA 66/SEBS-g-MA) composites were investigated on a block-on-wheel model friction and wear tester under dry sliding and water lubricating conditions. In order to further understand the wear mechanisms, the worn surfaces and scraps of samples were analyzed by scanning electron microscopy (SEM) and differential scanning calorimeter (DSC). The experimental results indicated that the wear mass loss and the friction coefficient of PA 66 decreased with the addition of rubber particles. The friction coefficients of PA 66 and PA 66/SEBS-g-MA composites under water lubricating condition are lower than those under dry sliding condition, but the wear mass losses are higher than those under dry sliding condition. The main wear mechanisms under dry sliding condition are the plastic deformation and mechanical microploughing. Whereas the main wear mechanisms under water lubricating condition are the mechanical microploughing and abrasive wear. 相似文献
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Laboratory studies indicate that sliding Ti6Al4V against soft ultra-high molecular weight polyethylene (UHMWPE) pins produces severe damage to the titanium and the lubricant (water) changes colour suggesting chemical change. Blackening of periprosthetic tissues associated with titanium wear debris was also observed in clinical investigations. To increase scientific understanding of the mechanism involved, systematic characterisation work has been conducted employing grow discharge spectrometry (composition), scanning electron microscopy (wear morphology) and cross-sectional transmission electron microscopy (phase identification). Experimental results show that hydrogen may play an important role in promoting the formation of abrasive particles in the Ti6Al4V/UHMWPE tribosystem under water lubricated conditions. The observed abnormal wear of Ti6Al4V by soft UHMWPE can be to a large extent attributed to hydrogen evolution and formation of titanium hydride. Based on experimental results and discussion, a hydrogen-assisted wear mechanism is proposed. 相似文献
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To achieve a hydraulic power system, it is important to control tribology because water has a lack of lubricity. Therefore, coated surface is necessary under water lubrication. Diamond-like-carbon (DLC)-coating is known as a useful material because of its high hardness and low friction, therefore it can be used as a coating durable for the water lubrication. Deposition methods of DLC-coating are developed in various ways. Particles called “droplets” are observed on the surface of DLC-coating depends on deposition methods and it can affect friction and wear properties. In this study, DLC-coating was prepared using a multi-cathode unbalanced magnetron sputtering (UBMS) system. The surface was polished with diamond slurry solution and aero lap to remove droplets. DLC-coatings were evaluated by tribo-tests before and after polishing. It is considered that some surface modification occurred. Moreover, the results of tribo-tests show that friction coefficients became lower and more stable than before polishing. Although partial delamination was observed after tribo-tests without polishing, no appreciable wear was observed after polishing. 相似文献
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The development of materials for tribological applications requires characterisation of their friction and wear behaviour. This characterisation is often based on tribological model testing, working with simple shaped specimens, running under well-defined conditions. Discrepancies in test results may arise from the fact that non-standard tests with different sets of operational parameters are used. An essential starting point for the development of tribological standards is knowledge of the main parameters that influence the tribological properties. One aspect that is not often adequately taken into account is the surface finish of the test specimens. Results are presented of friction and wear tests with self-mated SSiC couples (ball on disc), running in water in an oscillating sliding mode. The surfaces of the disc were ground, lapped, or polished, respectively, running against a polished ball. For certain test conditions, the influence of the surface finish on wear is found to be negligible, while for other conditions, the wear rate can differ by one order of magnitude or even more. The consequences for the standardisation of wear tests of ceramic materials are discussed. 相似文献
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A tribofilm was formed during wear tests of a Si3N4-white iron pair lubricated with distilled water. In order to clarify the formation of the film, the wear tests for Si3N4-white iron pair with different sliding distances were carried out on a ring-block tester, using distilled water as lubricant. The worn surfaces of white iron specimens were observed under SEM. Furthermore, the component and structure of the film were analyzed by using AES, XPS, FTIR and XRD. From the investigation, the following results are presented. During the wear tests of Si3N4-white iron pair lubricated with distilled water, the oxidation and hydrolysis of Si3N4 occur on the wearing surfaces, and a tribochemical film, which mainly consists of silica gel, is formed on the wearing surface. The reason for the film formation is that the carbides in cast iron spall off during the wearing tests and the spalling pits are left on the wearing surface of the white iron. Then, the debris of Si3N4 or its oxidized product are embedded into the pits, and are further oxidized and hydrolyzed. The products of reactions are concentrated in the pits and polycondensed into silica gel, and a silica gel film is formed on the wearing surface. The film protects both Si3N4 and white iron, and makes the paired surfaces smooth. Therefore, the friction coefficient of the pair is down to 0·02, and the wear rates of Si3N4 and iron are near zero. However, because the resultants of oxidation and hydrolysis of Si3N4 can not be enriched on the wearing surface of carbon steel to form an effective tribofilm, both friction coefficient and wear rate of Si3N4-carbon steel pair lubricated with distilled water are still high in value. 相似文献