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金属间隙密封气缸和一般橡胶密封气缸相比,具有低摩擦、高速和高频等特点。针对金属间隙密封气缸研制了一套寿命试验装置,详细介绍了试验装置的基本试验系统气动回路、测量系统气动回路和具体实现方法。最后,通过长期试验收集分析试验数据,对气缸失效临界值水平进行初步探讨。 相似文献
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传统气缸因复杂的摩擦特性难以实现高精度控制,基于振动减摩原理,开发了一款新型高频纵振减摩气缸。在保证密封性能的前提下,凭经验在活塞上设计了6种不同槽口夹角和槽宽的密封槽,并根据实际PID运动轨迹跟踪控制的精度情况,选取其中最优的密封槽。通过模态分析、谐响应分析和阻抗测试,确定了所开发新型气缸的一阶纵振共振频率为6328 Hz。摩擦力测试结果表明:高频振动确实可以减小气缸的摩擦,且激励电压越大减摩效果越好;最大静摩擦力最大减少了约64.46%,动摩擦力最大减少了约63.62%。 相似文献
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气缸中气动往复Y形密封圈在内外行程2种不同运动方向的变形差别比较大,产生的摩擦力也不一样。根据气缸功能的不同,气缸中Y形圈有2种不同的运动方向,即向着无压力侧方向运动和向着有压力侧方向运动。而Y形圈在2种不同的运动方向的变形差别比较大,产生的摩擦力也不一样。通过一种能分别测量气动往复Y形密封圈2个方向摩擦力的试验台,测量不同压力、不同速度、不同运动方向时Y形密封圈的摩擦力,探讨气缸工况对摩擦力的影响规律。结果表明:外行程方向的摩擦力明显大于内行程方向的摩擦力;随着压力的增大摩擦力也增大;在低速下,Y形圈摩擦力比较大,随着速度的增加,摩擦力先大幅下降后又缓慢上升。通过比较试验数据和有限元仿真结果,验证了试验结果的可靠性和试验方法的可行性,并计算了可用于有限元仿真的Y形密封圈不同速度下的摩擦因数,为研究和设计气动密封提供了基础数据。 相似文献
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为了解决相对运动条件下密封接头的泄漏量及摩擦力的测量问题,分析了技术上的关键问题,提出了用精密流量计间接测量质量流量,在张力和有相对运动的条件下用力传感器测量密封接头与钢索间的动摩擦力,并进行了对气源、恒压气室、试验装置和测控系统的设计.该方法满足动密封条件下的密封性和摩擦力的测量需要,并提供了一种实用的密封性测量方案. 相似文献
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无润滑活塞密封装置摩擦力的现有计算方法21、23没有考虑到气体在活塞环和气缸之间间隙中的运动特性、这些零件工作面的接触机理以及活塞环材料性能对实际载荷的大小和活塞环及整个密封装置的摩擦力大小的影响,致使计算数据和试验数据的差异相当大。 相似文献
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对金属往复滑动摩擦力-相对滑动速度的关系进行了试验研究,通过设计相对滑动速度曲线实现了无摩擦振动工况下的摩擦力-相对滑动速度关系的测量。文中还对摩擦振动工况下的摩擦力的测量作了探讨。本文的试验数据可作为摩擦振动和摩擦噪声理论研究的基础数据。 相似文献
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介绍了传统低摩擦气缸的结构,并指出其密封结构给气缸性能带来的限制,在此基础上,介绍了几种形式的新型低摩擦气缸,并对比了其特点和技术参数,给出了典型的应用实例,推荐了在典型应用中的控制回路。新型低摩擦气缸采用了滑动阻力更小的间隙密封构造,扩大了普通气缸中不能使用的低速范围及输出力控制的能力。 相似文献
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基于预滑—动态摩擦力矩估计模型的自适应前馈补偿方法 总被引:3,自引:2,他引:1
根据数控交流伺服工作台进给系统从静止到宏观运动的过渡时间,和零速度时刻的指令加速度大小呈反比关系,区分摩擦力矩的预滑动区和滑动区,由此提出基于力矩值估计的摩擦补偿方法;在设定指令加速度后,基于命令力矩值的摩擦力矩模型,不需要测量速度就可以补偿工作台进给系统中的摩擦。同时,考虑到参数的不确定性,设计非线性摩擦自适应控制方案,对其稳定性进行理论证明。在交流伺服工作台进给系统上对基于摩擦力矩值估计的自适应前馈补偿方法进行验证。试验结果表明,基于预滑—动态摩擦力矩估计模型的自适应前馈补偿方法能实现在不同指令加速度下对期望轨迹的跟踪,并能大大提高系统的跟踪精度。 相似文献
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The current research of direct yaw moment control(DYC) system focus on the design of target yaw moment and the distribution of wheel brake force. The differential braking intervention can effectively improve the lateral stability of the vehicle, however, the effect of DYC can be improved a step further by applying the control of vehicle longitudinal velocity. In this paper, the relationship between the vehicle longitudinal velocity and lateral stability is studied, and the simulation results show that a decrease of 5 km/h of longitudinal velocity at a particular situation can bring 100° increasing of stable steering upper limit. A critical stable velocity considering the effect of steering and yaw rate measurement is defined to evaluate the risk of losing steer-ability or stability. A novel velocity pre-control method is proposed by using a hierarchical pre-control logic and is integrated with the traditional DYC system. The control algorithm is verified through a hardware in-the-loop simulation system. Double lane change(DLC) test results on both high friction coefficient(μ) and low μ roads show that by using the pre-control method, the steering effort in DLC test can be reduced by 38% and 51% and the peak value of brake pressure control can be reduced by 20% and 12% respectively on high μ and low μ roads, the lateral stability is also improved. This research proposes a novel DYC system with lighter control effort and better control effect. 相似文献
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开发一种基于推力轴承结构的润滑膜厚与摩擦因数测量系统。该测量系统在较低速度下可实现膜厚与摩擦因数的同步测量,在较高速度下可通过保持架固定和玻璃盘回转模式实现润滑油膜测量,通过保持架自由回转和玻璃盘固定模式实现摩擦因数的测量。通过测量不同载荷下的润滑油膜厚度随速度变化曲线,以及与单点接触的测量结果进行定量对比,验证了该测量系统的可靠性。测量得到的摩擦因数曲线表明了滚动体打滑现象的存在。该测量装置为润滑剂特性和滚动轴承润滑特性研究提供了一种评价方法。 相似文献
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对20%Vol SiCp/AI复合材料与有机摩擦材料组成的摩擦副的摩擦磨损特性进行了试验研究.试验表明:该摩擦副在不同的速度情况下都具有平稳的摩擦系数.摩擦系数在一定速度范围内随速度增加而减小,而在超过一定速度后随速度增加而增大.对摩擦系数随速度变化的机理进行了讨论. 相似文献
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This study investigated the effect of various parameters of the friction–velocity relationship on the friction-induced vibration of simulated instrument panel components. The effect of subsystem stiffness and damping on the system response was also studied. A simple discretized model was utilized with subsystem properties that were intended to realistically model values of low, medium, and high stiffness components. Specifically, the metric of mean squared velocity was used as an indicator of the noise generated during the stick–slip process. It was found that the difference between the static and the asymptotic kinetic value of friction was the most important friction parameter in determining the resulting behavior. As stiffness and damping are increased, the mean squared velocity decreases. Additionally, results from single excursion tests on a variety of instrument panel material pairs showed good correlation between mean squared velocity and the difference in static and kinetic friction. 相似文献
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In this paper, the authors have systematically studied the friction characteristics of various Langmuir-Blodett (LB) films of cadmium salts of long alkyl chain fatty acids. The parameters chosen were the number of layers of LB film, the load, and the sliding velocity. The results showed that there exists a range of numbers of layers for which a kinetic friction coefficient value (uk)as low as 0.02 is obtained. On the other hand, the friction coefficient in-creased gradually as the sliding velocity increased. 相似文献
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微观摩擦与表面形貌相关性的试验研究 总被引:9,自引:0,他引:9
针对微机电系统存在的问题,阐述了微摩擦的测试方法以及表面形貌对微机械中摩擦性能的影响,试验研究了表面形貌对介于宏观和微观之间摩擦行为的影响。试验用研磨的方法在硅片表面制作了不同宽度的条纹,通过UMT微摩擦测试仪研究了在不同速度和载荷下氮化硅陶瓷球和试样间的摩擦行为。试验表明,在硅片上制作出合适的条纹有助于降低摩擦系数,在低载低速下出现了测力梁突然释放弹性变形能的情况,使得摩擦力和载荷不稳定,而且随着表面条纹间距增大,这种现象的频率也越来越高,并通过理论分析解释了这些现象。 相似文献
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Melting of an ultrathin lubricant film confined between two atomically flat surfaces is studied. An excess volume parameter
is introduced, the value of which is related to the presence of defects and inhomogeneities in the lubricant. Via minimization
of the free energy, the Landau-Khalatnikov kinetic equation is obtained for this parameter. The kinetic equation is also used
for relaxation of elastic strains, which in its explicit form contains the relative shear velocity of the rubbing surfaces.
With the numerical solution of these equations, a phase diagram with domains corresponding to the sliding and dry stationary
friction regimes is built at a fixed shear velocity. A simple tribological system is used to demonstrate that in the dynamic
case, three friction regimes can occur, namely, dry, stick-slip, and sliding friction. It is shown that a lubricant can melt
when the shear velocity exceeds a critical value and with elevation of its temperature. The dependence of the dynamic friction
force on the pressure applied to the surfaces, the temperature of the lubricant, and the shear velocity is considered. It
is shown that growth of pressure leads to the forced ordering and solidification of the lubricant. 相似文献