共查询到20条相似文献,搜索用时 78 毫秒
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首先通过标准摩擦磨损实验机得到了湿润滑条件下橡胶对钢摩擦副的有关摩擦学参数,探索了湿润滑条件下载荷和速度对摩擦系数的影响.然后对干摩擦、湿润滑和完全水润滑条件下的摩擦系数进行了对比分析. 相似文献
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当船舶艉轴承供水系统出现故障或轴承过载时,金属轴颈与橡胶轴承之间会发生局部接触而处于干摩擦状态下。为研究金属轴颈表面粗糙度对水润滑橡胶轴承干摩擦特性的影响,采用TIME3230表面粗糙度测量仪对金属轴颈表面微凸体进行测量,得到金属轴颈表面微凸体的位置参数分布曲线,并对其进行去噪处理;利用傅立叶变换重新构造去噪后的金属轴颈表面粗糙度分布,并依据理论计算金属轴颈-橡胶轴承摩擦副的摩擦因数。金属轴颈-橡胶轴承摩擦副的摩擦因数计算结果与实际情况吻合,说明建立的轴颈表面粗糙度分布模型合理。分析结果表明:在干摩擦状态下,金属轴颈-橡胶轴承摩擦副的摩擦因数随着表面粗糙度函数波幅的增大呈线性增大趋势,随着粗糙度分布函数的特征波长系数的增大呈非线性增大;润滑流动方向顺着加工纹理方向时,摩擦因数比垂直加工纹理方向和与加工纹理呈45°时的摩擦因数都小。因此,选择合理的轴承表面粗糙度的幅值和波长可以提高金属轴颈-橡胶轴承摩擦副的摩擦润滑性能;沿加工纹理加工、装配金属轴颈-橡胶轴承摩擦副,可降低摩擦因数。 相似文献
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与传统的金属轴承不同,水润滑轴承一般由非金属材料制成,材料的性能是决定轴承工作性能和使用寿命的一个主要因素,而橡胶材料是水润滑轴承的最佳选择。通过在船舶尾轴承试验机上进行水润滑橡胶尾轴承摩擦、磨损模拟试验,研究了橡胶尾轴承的摩擦原因及摩擦因数的影响因素和橡胶尾轴承的磨损原因及其影响因素。 相似文献
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八纵向沟水润滑橡胶轴承润滑性能研究 总被引:8,自引:2,他引:6
水润滑橡胶轴承是水下最适宜的轴承之一,笔对潜水泵上常用的八纵向沟水润滑橡胶轴承,在水润滑条件下的润滑机理进行了实验研究,根据实验结果剖析了影响摩擦系数的主要因素及其影响规律,并据此提出了一组实用设计参数。 相似文献
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用热压成型法分别制备了纳米、微米石墨填充聚四氟乙烯(PTFE)的复合材料,对纯PTFE和复合材料进行了硬度、耐磨性和拉伸试验,用SEM观察了拉伸断口形貌.结果表明:纳米和微米石墨均能提高复合材料的硬度和耐磨性,而复合材料的抗拉强度和断后伸长率均有所下降;纳米石墨/PTFE复合材科的硬度、耐磨性、抗拉强度和断后伸长率均比微米石墨/PTFE复合材料的高;当纳米石墨质量分数为7%时,复合材料的综合性能较好,当质量分数大于7%后,复合材料的断后伸长率迅速下降;纳米石墨与PTFE相容性较好,在PTFE中的分布均匀. 相似文献
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Palyno‐morphological characteristics of gymnosperm flora of pakistan and its taxonomic implications with LM and SEM methods 下载免费PDF全文
Raees Khan Sheikh Zain Ul Abidin Mushtaq Ahmad Muhammad Zafar Jie Liu Hafiza Amina 《Microscopy research and technique》2018,81(1):74-87
The present study is intended to assess gymnosperms pollen flora of Pakistan using Light Microscope (LM) and Scanning Electron Microscopy (SEM) for its taxonomic significance in identification of gymnosperms. Pollens of 35 gymnosperm species (12 genera and five families) were collected from its various distributional sites of gymnosperms in Pakistan. LM and SEM were used to investigate different palyno‐morphological characteristics. Five pollen types (i.e., Inaperturate, Monolete, Monoporate, Vesiculate‐bisaccate and Polyplicate) were observed. Six In equatorial view seven types of pollens were observed, in which ten species were sub‐angular, nine species were Traingular, six species were Perprolate, three species were Rhomboidal, three species were semi‐angular, two species were rectangular and two species were prolate. While five types of pollen were observed in polar view, in which ten species were Spheroidal, nine species were Angular, eight were Interlobate, six species were Circular, two species were Elliptic. Eighteen species has rugulate and 17 species has faveolate ornamentation. Eighteen species has verrucate and 17 have gemmate type sculpturing. The data was analysed through cluster analysis. The study showed that these palyno‐morphological features have significance value in classification and identification of gymnosperms. Based on these different palyno‐morphological features, a taxonomic key was proposed for the accurate and fast identifications of gymnosperms from Pakistan. 相似文献
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以轨迹拟合法为基础,将目标预测问题转化为对预测模型参数优化搜索的问题。结合MAS、BP网络和位置预测原理,提出将近距离目标视为刚体。其状态按自由度划分为6个,其中3个自由度表示空间位置,另外3个自由度表示角的转动向量,6个自由度看作6个子网,分别进行子网预测,再进行组网的近距离目标预测法。最后,以无人机为例对算法进行仿真计算,验证了其正确性和可行性。 相似文献
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