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根据轧制时轧件金属发生塑性变形特点及摩擦副间的介质实际情况,经理论分析认为冷轧塑性加工中的摩擦性质是混合摩擦或边界摩擦,并得到了实验的验证。 相似文献
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对过载时能自动发出控制信号,从而切断驱动电源的摩擦安全离合器的结构、原理、特点、技能及设计要点进行了分析研究,为这种新型安全离合器的推广应用提供了理论基础。 相似文献
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原国家经贸委节能信息传播中心 《中国设备工程》2004,(6):47-47
概述呼和浩特发电厂冷却水系统6甲循环水泵应用摩擦表面再生技术以及取得理想效果的案例;介绍了摩擦表面再生技术的作用原理,从现场测试、循环水泵的噪声、维修工作量、经济和环境效益五方面说明其应用效果,并阐述了市场潜力及推广前景。 相似文献
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对摆动齿轮箱自动压紧摩擦驱动旋转舞台的传动原理和特点作详细的介绍,并给出了主要参数的选择和计算方法。 相似文献
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在高频循环载荷作用下,材料疲劳裂纹的萌生与扩展过程伴随着明显的温度变化,该温度变化反映材料内部结构的损伤特征。通过20 kHz的超声疲劳试验,研究一种碳锰钢在超高周疲劳加载条件下的内部疲劳裂纹萌生与扩展过程中温度的演化过程。通过对该材料在疲劳损伤过程中,内部裂纹间的摩擦生热机理分析,从微观角度出发,结合分形理论,建立内部裂纹微观结构的摩擦模型,数值模拟超声疲劳过程中材料内部疲劳裂纹面间的摩擦生热情况,并定量地计算该过程中由裂纹间摩擦所导致的温度上升,将模拟结果与试验结果进行比较。探究高频疲劳载荷下微裂纹扩展与摩擦生热的关系,并结合超高周疲劳裂纹扩展公式,建立超声疲劳过程中的裂纹扩展与裂纹面温度演化关系的模型。 相似文献
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基于微凸体侧接触模型,推导了机械密封端面混合摩擦热计算式,研究了转速、摩擦间隙和粗糙度对常用机械密封端面混合摩擦热的影响。结果表明:常用混合摩擦状态下的机械密封端面微凸体接触多为第Ⅱ类弹塑性接触;当转速ω ≤ 2 800 r/min时,微凸体接触摩擦热所占比重较大,但随着转速上升,黏性摩擦热比重逐渐增大至百分之百;随着摩擦间隙d的增大,黏性摩擦热和微凸体接触摩擦热曲线均呈下降趋势,当d ≥ 2.8σ时,微凸体接触摩擦热减小至零,而黏性摩擦热随d变化不大;随着粗糙度的增加,端面摩擦热先下降后上升,在近1.6 μm处最小,因而在机械密封设计时,存在某一粗糙度使混合摩擦热最少。 相似文献
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Findings from the numerical study of the heat duty of an oil-cooled friction pair in a multidisk brake of a wheel tractor
are presented. The boundary problem is formulated to describe the heat processes in an oil-cooled friction pair with radially
positioned oil-control grooves under frictional heating. It is solved by the finite-element method for the case of the tractor’s
braking on a protracted descent. The features of the temperature field formation in an oil-cooled friction pair are identified
and a functional dependence of the maximum temperature on the friction contact surface on the coefficient of overlapping of
the disc friction surfaces is obtained. 相似文献
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The paper reviews the main stages of the formulation, development, and improvement of the frictional heat problem. At present its evolution enables to proceed from problems for a local contact spot to problems for specific full-sized friction units. Features of the consideration of some basic parameters when formulating and solving analytically the frictional heat problem for tooth gears are discussed and the real values of the essential parameters are specified. These parameters are the contact duration factor, the temperature flash duration, and the real temperatures capable of inducing structural and phase transformations in surface and subsurface layers of the mated parts. 相似文献
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面接触条件下织构表面摩擦特性研究 总被引:7,自引:0,他引:7
为研究织构表面对面接触摩擦副摩擦特性的影响,设计和制造4个表面高度算术平均值相同、表面微凹坑面积占有率分别为7%、14%、21%、28% 的试件,选用HDM20端面摩擦磨损试验机,针对油润滑和脂润滑两种润滑剂,在不同载荷、转速等工况和不同摩擦副配对材料等条件下进行了试验研究,探讨表面形貌对摩擦特性的影响规律,并使用Talysurf CCI Lite 非接触式三维光学轮廓仪对试样进行三维表面测量,采用ISO25178定义的体积参数和连通性系数对三维表面形貌进行表征,从而得出表面体积参数及连通性系数与摩擦因数的关系。结果表明:在油润滑条件下表面形貌的微观结构特性对摩擦的影响要比脂润滑条件下的更显著;在钢对铜摩擦副条件下织构表面的摩擦因数变化比较复杂,在钢对钢摩擦副条件下织构表面的摩擦因数变化相对平稳;在不同的条件下,最优的表面微观结构特性也不同;将连通性系数和体积参数结合起来对表面形貌进行表征将更有利于表面微观结构特性的摩擦学设计。 相似文献
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The frictional behavior of certain nitrogen-containing ceramics, such as silicon nitride, alpha sialons, and beta sialons as journal materials were studied in conformal contact with a tin-coated Al-Si alloy (Al-Si/Sn), forged 1141 steel and a cast aluminum matrix composite with silicon carbide reinforcement (cast MMC) as bearing materials while lubricated with SAE WW30. A case-hardened 1016 steel was also tested with the Al-Si/Sn and cast MMC bearings under the same conditions. The friction values of the ceramic and the steel journal wear pairs were compared and their frictional behaviors were evaluated. Silicon nitride and one of the beta sialons exhibited higher load-supporting capacities than the others when they were in contact with the 1141 steel bearings. The journal surface roughness was found to be very important when the journals were in contact with the Al-Si/Sn bearings. The frictional behavior of the ceramics and cast MMC pairs and the steel and cast MMC pairs were controlled by different wear mechanisms, namely for the former, hard particle pull-out and matrix plowing, and for the latter, iron transfer from the journal to the cast MMC bearing surface. 相似文献