电容式压力传感器的开关电容接口

引言目前,扩散硅压阻式桥路和离子注入式硅膜片集成压力传感器的线性都很好,但它们的温度特性差,功耗也较大。相比之下,电容式压力传感器的温度特性要好得多,功耗也小。它的灵敏度是压阻桥路压力传感器的10～20倍,正在研制中的开关—电容(SC)接口非常适用于     

新型双级机械密封小流量泵的研制

介绍新型双级机械密封小流量TLS型开式离心泵和轴向入口XWBS型旋涡泵的结构设计和水力设计 经水力试验和现场应用表明,该型泵具有良好的技术性能和密封性能,完全能够满足安全无泄漏可靠运 行的要求.     

工程机械用压敏开关,温控开关的研制

阐述了工程机械用ＨＢ２１８０系列压敏开关和ＨＢ２２８５系列温控开关研制原理、特点及其研制成功并进行工程化生产的重大意义,具体介绍了该产品的应用领域及推广应用前景。     

PMC系列电容式压力变送器及其在液位检测方面的应用

PMc系列电容式压力变送器介绍 PMC系列电容式压力变送器是德国恩德斯+豪斯有限公司(Endress+Hauser Gmbh+Co)在80年代中期开发研制出的PMC系列产品。 PMC系列产品采用目前世界先进的电子膏瓷技术、无中介液的干式压力测量技术、厚膜     

流量开关在中央空调系统中的应用研究

分析了中央空调水系统中靶式流量开关、压差式流量开关安装和使用特性,研究了压差式流量开关在中央空调水系统的应用,得出了压差式流量开关是中央空调机组水流控制最优选择的结论。     

微型数字压力控制器的研制与应用

介绍了一种微型数字压力控制器的研制与应用，通过与国外同类产品的对比分析，论述了该产品的优异性能。     

微型电容式压力传感器的制作与测试

从应用开发MEMS产品的实用角度出发，介绍了利用硅一硅键合技术制作的微型电容式压力传感器，给出了详细的制作工艺及主要工艺步骤图。对微传感器所用的测试装置的组成、测试电路的工作过程进行了详细介绍和深入分析。最后对不同尺寸的微传感器器件进行了测试，并对测试结果进行具体分析。结果表明：该微传感器具有良好的线性工作范围、良好的稳定性和较高的灵敏度。     

一种新型静压轴承保护装置—流量开关

由于静压轴承是纯液体摩擦,它具有摩擦力小、寿命长、承载能力强、回转精度高等诸多优点,因此,在机械设备上得到越来越广泛的应用。但是,静压轴承对润滑清洁度的要求较高,因而静压轴承的很多故障集中体现在因节流器的堵塞而造成的静压轴承的压力油腔供油不足,以及轴承磨损和烧坏。为此,我们研制了新型液压轴承保护装置———流量开关,它能提高润滑油清洁度,进而起到保护静压轴承的作用。１流量开关的结构如图１所示,流量开关主要由非导磁材料的铝合金阀体１、复位弹簧２、舌簧开关３、嵌有磁铁的塑料阀芯４组成;其流量大小应根据…     

液流转换套铣自洁工具的研发和应用

针对修井完井工艺研发的液流转换套铣自洁工具,可实现液流由正循环洗井转换为反循环洗井即液流转换功能,可有效地将井筒中套铣落物清洗出井筒,为后期打捞提供一个清洁的井筒环境.经现场试验,该工具能够克服或避免现有技术中存在的缺点或不足,实现套铣管柱液流转换套铣自洁工具以下井筒内反循环洗井功能、确保套铣井筒清洁、无大块落物存在的修井完井工艺,性能安全可靠,可以进行大规模推广应用.     

Developing Flow Pressure Drop and Friction Factor of Water in Copper Microchannels

Experiments of de-ionized water flowing in microchannels made in copper blocks were carried out to obtain pressure drop and friction factor and to investigate any possible discrepancies from conventional theory. Three channels with widths of 0.5 mm, 1.0 mm, 1.71 mm, a depth of 0.39 mm and a length of 62 mm were tested. For adiabatic tests, the temperature of the working fluid was maintained at 30 ℃, 60 ℃ and 90 ℃ without any heat fluxes supplied to the test section. The experimental conditions covered a range of Reynolds numbers from 234 to 3,430. For non-adiabatic tests, the inlet temperature and heat flux applied were 30 ℃ and 147 kW/m2 and only for the 0.635 mm channel. The friction factors obtained for the widest channel （Dh = 0.635 mm） are reported for both adiabatic and non-adiabatic experiments to assess possible temperature effects. The paper focuses on the effect of hydraulic diameter on pressure drop and friction factor over the experimental conditions. The pressure drop was found to decrease as the inlet temperature was increased, while the friction factors for the three test sections did not show significant differences. The experimental friction factors were in reasonable agreement with conventional developing flow theory. The effect of temperature on friction factor was not considerable as the friction factor with and without heat flux was almost the same.     

Developing an Integration Framework to Support the Information Flow Between PDM and MRP

Integrating various kinds of business application has attracted much attention in the business to business (B2B) market. The integration of the production planning functions and engineering design functions is an important area which has been addressed recently by some major enterprises. This paper proposes a methodology to support the integration of information flow between the applications of product data management (PDM) and manufacturing resource planning (MRP). A three-level structure including model development, model analysis, and system implementation was developed. An approach applying the concepts of semantic similarity to find the "common" objects used in different business applications was also proposed. These objects were used as a buffer for the information integration. In addition, a set of business rules was developed to govern the information flow between PDM and MRP. The proposed methodology has been implemented by integrating two commercial PDM and MRP software modules.     

三元点元素叶片展开划线样板CAD参数化设计

将三元点元素叶片展开划线样板的设计与绘制过程,通过编程,以ＡｕｔｏＣＡＤ参数化自动设计代替传统设计方式。     

无轨胶轮车用防爆开关磁阻电动机系统设计

调研的方法,涵盖了模型辨识和解析、设计案例的解析、关联的参数运算等。通过研究,明晰了无轨胶轮车用防爆开关磁阻电动机系统相关设计参数和设计内容。探究结果为:防爆无轨胶轮车特有的开关磁阻,耗费掉的油量偏多,噪音和尾气污染严重,也因此导致了运输成本偏高,使用容易受到限制。结论为:建议把纯电机,作为无轨胶轮车的驱动系统,以便限缩能耗,提升开关原有的防爆性能。     

机械式惯性开关设计

针对引信中的普通开关无法可靠闭合自锁接通电路,设计了一种机械式惯性加速度开关,利用炮弹发射时的过载使其闭合并且自锁,使电路有效、可靠的接通。实验和仿真结果表明,该开关可以实现可靠闭合自锁,为在实际中的应用提供理论依据。     

A High-Current Vacuum Closing Switch

A high-power pulsed vacuum closing switch is described. The switch consists of several vacuum diodes with narrow gaps (1 mm) connected in series. The switch closing time (10 ns) is determined by the time of the short-circuiting of this diode by a plasma in the near-electrode regions. The switch closing rate and the values of the switched currents and voltages are estimated. The results of experiments in a test bench circuit are presented. The switch can be used in pulsed power technology to solve such problems as voltage-pulse front sharpening and trailing-edge cutting, the short-circuiting of the reflected pulse, etc.