冷却油路型射流管式伺服阀的热力学研究

 射流管式电液伺服阀因抗污染能力强、灵敏度高、失效对中等特点,被广泛应用于航天、航空、船舶等领域。介绍了冷却油路型射流管式电液伺服阀的结构原理,建立了稳态传热过程的热流量方程。利用有限元软件ANSYS 对冷却油路型射流管式电液伺服阀进行了热力学分析,并分析了力矩马达内部温度分布以及热梯度等物理量。试验验证了冷却油路型射流管式电液伺服阀的冷却效果,为冷却油路型射流管式伺服阀的结构设计、热力学研究提供了理论依据。     

射流管式与喷嘴挡板式电液伺服阀之比较

射流管式与喷嘴挡板式电液伺服阀是目前世界上运用最普遍的典型两级流量控制伺服阀.该文对两种阀的结构、工作原理及特点分别作了比较与介绍,并着重分析了射流管式伺服阀在可靠性及工作性能方面的优势.     

射流管电液伺服阀在全尺寸飞机结构静力/疲劳试验中的应用研究

该文主要论述了射流管电液伺服阀在全尺寸飞机结构静力/疲劳试验机中的应用研究。介绍了射流管电液伺服阀的结构、工作原理,飞机静力/疲劳试验系统的结构。阐述了射流管电液伺服阀在飞机静力/疲劳试验系统中应用的优点。并说明了射流管电液伺服阀在试验中的应用效果。     

射流管电液伺服阀专题讲座

第四章伺服比例阀的发展 1 伺服阀与比例阀简介 电液伺服阀是在二战期间由于飞行器等军事装备对控制系统快速性动态精度的更高要求而发展起来的,并在战后逐渐用于民用和工业设备.它是一种接受模拟量电控制信号,输出随电控信号大小和极性变化、且快速响应的模拟量流量和(或)压力的液压控制阀.根据其液压放大器的不同,主要分为喷嘴挡板式伺服阀和射流管式伺服阀[1].电液伺服阀具有体积小、功率放大率高、直线性好、响应速度快、运动平稳可靠、能适应模拟量和数字量调节等优点,在各种电液伺服系统中得到特别的重视.     

超声波电机控制的射流管阀的试验研究与性能分析

针对一种采用超声波电机取代力矩马达控制的射流管式伺服阀的原理样机进行研究,介绍了这种新型射流管式伺服阀的工作原理,设计测试系统对其进行综合特性试验并分析其性能.根据试验结果,这种新型射流管阀相对于由力矩马达控制的射流管阀具有更高的控制精度,同时工作压力有较大的提高.     

上海衡拓液压控制技术有限公司

<正>企业介绍上海衡拓液压控制技术有限公司是中国船舶重工集团公司第七〇四研究所电液伺服阀产业部转制而成立。七〇四所创建于1956年,隶属于中国船舶重工集团公司,长期从事航船机电设备的研发、制造工作,是国家一类研究所。1985年七〇四研究所在国内率先独立生产了射流管式电液伺服阀。2012年1月,转制成为专业的伺服阀公司,专业销售、设计、生产和服务射流管电液伺服阀。同样也是国内较先具有批量生产射流管伺服阀及相关产品能力的单位,并为相关产品国标、军标的归口单位。     

射流管电液压力伺服阀的设计与研究

简单介绍了压力伺服阀的应用和分类.针对市场需求,中船重工七0四所在已有射流管技术的基础上研制了抗污染能力强的两级射流管电液压力伺服阀,其前置级采用射流放大器,该阀目前已得到成功应用.对其动静态特性进行了分析,并进行了试验研究.同时,介绍了射流管电液压力伺服阀的优点.     

《极端环境下的电液伺服控制理论及应用技术》

本书主要涉及作者多年来所从事的飞行器和重大装备电气液伺服控制基础理论和应用技术的最新研究成果。内容包括：飞行器和重大装备的极限环境,如极端温度（极端高温、极端低温）、振动、冲击和离心加速度;航空液压油、航天煤油、生物质能油电液伺服机构;流体伺服控制元器件,如电液伺服阀、喷嘴挡板阀、射流管伺服阀、气动伺服阀、电液伺服作动器的基本原理;电液伺服控制理论;极端温度下的电液伺服阀基础理论和流场;振动、冲击环境下电液伺服阀基础理论和分析实例;离心加速度环境下电液伺服阀数学模型和分析实例;电液伺服阀优化设计方法;带补偿节流器的电液伺服阀新结构.     

射流管电液伺服阀的特点

以射流放大器作为前置级的电液伺服阀(简称射流阀),比喷嘴档板作为前置级的电液伺服阀(简称喷档阀)有更多优点。本文以对比形式来说明射流阀的特点。射流阀在使用上的特点电液伺服阀在系统中所出现的故障,约80%是由于工作油液的污染而引起的,主要表现为“堵、卡、漂”。现将这三个方面的     

也谈喷嘴挡板伺服阀与射流管伺服阀的比较

该文对现阶段最普遍的喷嘴挡板式电液伺服阀和射流式电液伺服阀进行了比较,重点在电液伺服阀的输入功率、输出功率、频率响应、零位泄漏、温度敏感度、可靠性、滑阀驱动力等方面进行了对比。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.