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一种圆柱螺旋线式阻尼孔王明川在液压传动系统的回路中,经常要用到各种液压阻尼单元。最常用的是薄刃节流孔和短管型阻尼孔。薄刃孔液阻的大小与孔的长度无关。当该孔两端的压差一定时,液阻只与其过流面积成反比。阻尼孔的液阻与孔的长度成正比,与过流面积成反比。因此... 相似文献
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研制一种适合对各种液压孔口或缝隙进行高低温流体力学试验的新型试验装置,运用该装置对具有不同几何参数的液压阻尼孔进行在-50~80℃宽温度范围内的流动特性试验,研究以普通抗磨液压油HM46和低温抗凝减振器油TITANSAF5045为工质及其温度变化时对液压阻尼孔流量-压力特性曲线、幂指数和流量系数的影响,研究表明,在低温条件下,液压阻尼孔的流量系数均因油液黏度增大、流动性变差而呈线性下降的趋势,从宏观上看,HM46通过液压阻尼孔时的流动稳定性较差,其对应流量系数的下降幅度明显大于TITAN SAF 5045对应的下降幅度,厚壁小孔流量系数的下降幅度明显大于薄壁小孔对应的下降幅度。研究所获得的新型试验装置、试验数据分析方法和具体理论公式为深入研究和优化现代液压元件在宽温度范围内的动态性能提供新型试验平台与理论基础。 相似文献
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水介质在微间隙流道内的流动特性试验 总被引:1,自引:1,他引:1
讨论了水压传动中柱塞运动副环形微间隙流道内流体流量的主要影响因素 ,研制成一种测试柱塞与缸体无相对运动时其微间隙中流体流量的试验研究方法及测试装置。试验结果表明 :该测试方法是可行的 ,在微米级间隙流道内水的流动规律不同于层流流动 ,其间隙大小对流量的影响比层流流动中间隙的影响要小得多。试验结果在水压传动元件和执行机构的结构设计中具有广泛的应用前景。 相似文献
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高压水射流清洗机采用溢流调压阀和转速调节阀组合控制,采用异化阻尼孔结构的溢流调压阀满足了对发动机动态调速要求。通过对溢流调压阀进行动态优化分析和实验试用,结果表明,舍弃阻尼孔功能的溢流调压阀性能稳定,由于消除了阻尼孔的阻滞作用,开关喷枪所产生的水击波的压力信号得到了快速传递,从而实现该阀组对发动机的实时控制。 相似文献
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针对深孔镗削加工中的颤振问题,设计了一套具有多个细长孔的双镗杆刀具系统结构,通过细长孔阻尼作用,抑制镗削加工过程中刀具系统的颤振。根据流体力学环形间隙流动以及细长孔阻尼理论,建立双镗杆刀具系统结构的数学模型,利用MATLAB进行数值模拟;利用Fluent软件对双镗杆刀具系统结构的内部流场进行仿真,得出流场域的阻力系数增大;建立镗削过程中的振动模型,运用Simulink对其进行动力学仿真得到振动时域图,直观显示了切削液流经具有多个细长孔的阻尼通道能有效抑制深孔镗削过程中的颤振。 相似文献
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EXPERIMENTAL INVESTIGATIONS OF CAVITATION EFFECTS ON FLOW CHARACTERISTICS OF SMALL ORIFICES AND VALVES IN WATER HYDRAULICS 总被引:3,自引:0,他引:3
Zhu Bihai Zhang Tiehua Huang Yan Li Zhuangyun School of Mechanical Engineering Huazhong University of Science Technology Wuhan China 《机械工程学报(英文版)》2002,15(4):380-384
The flow characteristics and cavitation effects of water passing through small sharp-edged cylindrical orificesand valves of different shapes in water hydraulics are investigated. The test results using orifices with different aspect ratios and different diameters show that the flow coefficients in the case of non-cavitating flow are larger than that of flow inthe case of cavitation occurrence. The flow coefficients of flow with cavitation initially decrease as Reynolds number increases and ultimately tend to be of constant values close to contraction coefficient. Large aspect ratio has an effect ofsuppressing cavitation. The experimental results about disc valves illustrate that the valves with sharp edge at large opening are less affected by cavitation than that at small opening. Throttle with triangle notch has better anti-cavitation abilitythan that with square notch. The flowrate of the throttle with square notch is significantly affected by the flow direction orthe flow passage shape. 相似文献
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Liu YinshuiNie SonglinZhu YuquanHe XiaofengLi ZhuangyunSchool of Mechanical Scienceand Engineering Huazhong University of Scienceand Technology Wuhan China 《机械工程学报(英文版)》2004,17(3):450-453
Experimental investigations are made on the effects of operating conditions on the flow characteristics of throttle when tap water is used as the working media. The researched throttles include cone poppet valve, ball valve, disc valve and dumping orifice. Operating condition includes poppet lift, working media, back pressure, medium temperature, etc. Because the vapourous pressure of water is much higher than that of oil, cavitation is easier to occur in water hydraulic elements and systems, so the effects of operating conditions on the cavitation characteristics of throttle are also researched. 相似文献
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设计与试制了不同规格的波形套试件,测试了其工作特性。建立了波形套工作状态下的数学-力学模型,求解了理论特性,并用ANSYS进行了数值模拟,理论解、模拟解与试验结果吻合。揭示了波形套的定量工作特性以及几何参数对其特性的影响规律:在最大外径不变时,随着波纹圆角半径的增大,特性曲线中弹性区的斜率增大,进入塑性变形所需要的压力亦增大;在波纹圆角半径不变时,随着波形套最大外径的增大,特性曲线中弹性变形区的斜率减小,进入塑性变形所需要的压力亦减小。波形套工作特性的理论与试验研究,为确立其设计方法,促使该类零件广泛应用奠定了基础。 相似文献
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采用精密的机械加工和独特的气动旋转密封技术,研制出可调压可视化微间隙Couette流变仪。外圆筒旋转内圆筒静止的特点,使该流变仪能产生剪切速率高达105/s数量级稳定的纯剪切流。利用商业旋转流变仪,测量试验用中、低粘度硅油在低剪切速率和不同温度下的粘度,应用粘温关系,推算出高剪切速率下粘性热使粘度下降的量,其值与微间隙Couette流变仪的测量结果较为吻合。在一定的切应力下,观察到淡水和中低粘度硅油在微间隙中发生剪切空化的现象,发现剪切空化的发生还强烈依赖于流体中气体的相对溶解量。 相似文献
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Zheng Ming College of Biology Environment Engineering Jiangsu University Zhenjiang ChinaChen Chi Shanghai University 《机械工程学报(英文版)》2002,15(4):328-333
From basic equations of gas-liquid, solid-liquid, solid-gas two-phase flow, the calculating method on flow transients of two-phase flow is developed by means of characteristic method. As one example, a gas-liquid flow transient is calculated and it agrees well with the experimental result. It is shown that the method is satisfactory for engineering demand. 相似文献
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压电石英晶片扭转效应理论研究与验证 总被引:2,自引:0,他引:2
从各向异性弹性理论和麦克斯韦电磁理论出发,较系统地探讨了圆形压电石英晶片扭转效应理论,得出了扭转应力场与非线性极化电场分布规律,并采用有限元法求得了极化电荷电场在压电片内的分布。根据理论分析,用分割电极法有效地在压电片表面布置了检测电极,理论与试验结果均表明电极检测的极化电荷量与外转矩成线性关系,理论与试验基本符合。这些研究为新型转矩传感器与测力仪的开发奠定了必要的理论基础。 相似文献
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用冗余驱动方法进行柔性机构动力平衡的理论与试验研究 总被引:1,自引:0,他引:1
采用冗余驱动方法对柔性机构的动力平衡进行了研究。建立了具有冗余驱动的柔性连杆机构动力学模型,从理论上阐述了冗余驱动的平衡原理;给出了柔性机构最优平衡方法及其数值仿真结果;用附加冗余驱动电机的方法对一平面4R柔性连杆机构的动力平衡进行了试验研究,试验结果与理论分析吻合,充分表明了该方法的有效性和优越性。 相似文献
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RESEARCH ON THE PERFORMANCE OF NEW TYPE OF PROPORTIONAL PESSURE AND FLOW CONTROL VALVE 总被引:1,自引:0,他引:1
Quan LongMa JianWang YongjinInstitute of Mechatronics Taiyuan University of Technology Taiyuan China 《机械工程学报(英文版)》2003,16(3):281-284
A new closed loop flow controlling principle through correcting the valve's opening area while load pressure is changing is carried out. Further more a principle using only one proportional valve to compound control pressure and flow is suggested. By using very simple proportional throttle valve in structure, the functions that five kinds of proportional valves or any two of them combined possess can be complimented. After analyzing, comparing, and testing the dynamic and static characteristics of valve with different controlling principles and main valve structure styles, the optimized structure styles and control methods are achieved. 相似文献