查询词典 mechanical device

But in practical operating, overvoltage caused by reignition of the vacuum switching device frequently appears, and it result in damage of the capacitor bank or the switchgear itself. Ensuring the switchgear against reignition and installing a protective device are two main approaches to avoid the phenomenon. In this paper, a study on overvoltage caused by reignition due to capacitor bank switching with the vacuum switching device and its preventive measures are carried out. The main work which has been done and researches are as follows: 1. The producing mechanism of overvoltage and its influence factor are analyzed. It is pointed out that single-phase reignition is the main reason for damage of the switchgear and two-phase reignition is the main reason for damage of the capacitor bank,so overvoltage of single-phase reignition and two-phase reignition are the emphases of prevention. 2. Analysis of the special working condition of the operating switch for capacitor bank is carried out. It indicates that the vacuum switching device is difficult to realize no-reignition under this operation condition, so it is more practical to adopt protection devices. 3. Analyses of protection effect of RC and MOA and their shortages are carried out. It shows that the two methods can only restrain effectively overvoltage caused by single-phase reignition, and they cannot protect the capacitor bank when reignition of two-phase occurs. 4. The operation principle of G-R damping device is analyzed and discussed emphatically.

本文针对真空开关投切电容器组时因重燃而产生的过电压及其防治措施进行了研究，所开展的主要工作和研究结果如下： 1、对过电压的产生机理及其影响因素进行了分析，指出单相重燃是导致开关设备损坏的主要原因，而两相重燃则是导致电容器组损坏的主要原因，因此单相重燃和两相重燃过电压是防护的重点； 2、对电容器组操作开关的特殊运行条件进行了分析，指出在这种运行条件真空开关难于实现不重燃，因此采用保护装置更具有现实意义； 3、对RC与MOA的保护效果和存在的不足进行了分析，指出这两种方法均只能有效抑制单相重燃过电压，而不能在发生两相重燃时保护电容器组； 4、重点对G-R阻尼装置的工作原理进行了分析和讨论，指出该装置接入后线路中将会出现两种频率的高频振荡，而电容器组上的过电压是由这两种振荡共同决定的； 5、根据对上述两种振荡的分析指出存在一个最佳电阻值使得过电压最低，并提出了电容器组电压和最佳电阻值的近似求解方法； 6、使用电气暂态分析软件MATLAB对G-R装置的保护效果进行了仿真计算，证实该装置确实可以有效抑制重燃时的电容器组过电压； 7、根据仿真与近似计算结果的偏差提出了近似计算的修正方法，经过修正后的过电压计算结果与仿真结果吻合较好； 8、对G-R装置中放电装置G与阻尼电阻R的要求进行了分析，指出采用编织电阻和真空间隙可能是最佳选择。

Safety Belt Tension Furling Device: While a collision happens, if the driver uses a safety belt without tension furling device, the injury may happens by the collision on the instrument board or the steering wheel etc.; Safety belt tension device uses the gas generator in the safety belt tension furling device touched by the speed acceleration of collision, the gas expansibility generated will make the tension device rotate in the reverse direction, bringing the passengers back on the seats, protecting the passenger's security.

对于安全带预张紧卷收器：在发生碰撞事故时，若使用非张紧普通安全带，仍然有可能触及汽车方向盘和仪表板等部位而使乘员受伤；预紧式安全带利用撞车时的加速度触发安全带卷收器中的气体发生器，产生的气体膨胀力使卷收器反向旋转而收紧织带，将乘客向后拉向座椅，从而更可靠地保护乘客的人身安全

A high-precision liquid filter includes a liquid treating device among which the interior has a filtrating device with filter screen along the periphery set up, the lower end of its one side is the liquid inlet, and the upper end is the treated liquid outlet and the lower end is the impurity outlet, a steel plate for hoisting the filtrating device is set up in connection below the cover shell at the upper end of liquid treating device in which or on its outside a magnetizing device is further set up and on its bottom two stands are fixed.

高精度液体过滤器，包括一液体处理装置，其中内部设置有周缘设置有滤网的过滤装置，其一侧下端为液体入口，上端为处理过的液体出口，下端为杂质出口，处理装置上端盖壳下连设一用以吊设过滤装置的钢板，液体处理装置内或外侧还设置有一磁化装置，液体处理装置底部设有两支架。

Taking a general view of the paper, major innovative ideas and returns are as follows: The main innovative ideas are as follows: 1. The paper put forward the new idea that combine water-saving drilling with rotary percussion drilling creatively according to the present situation of water resource lack seriously and the background of implementation of state geological survey strategy. 2. The working principle of new designed system of water-saving hydraulic percussion device completely different from traditional hydraulic percussion device, the system can carry out rotary percussion drilling on the condition that no surface water be consumed, and achieve the purposes that saving surface water, cutting cost and improving drilling efficiency. 3. The design conception of steel ball percussion device is very novel, the percussion device is durable, with a simple structure, at the same time drilling efficiency would be improved highly and drilling cost would be reduced greatly when drill with the steel ball percussion device.

综观全文，论文的主要创新点及研究成果如下：主要创新点： 1、结合我国许多地区水资源严重短缺的现状以及国家实施地质大调查战略的背景，创造性地提出了&节水钻探&和&回转冲击钻进&结合起来的新思维； 2、设计出的节水型液动冲击器系统，其工作原理跳出了传统液动冲击器要消耗大量地表水的原理模式，在基本不消耗地表水的情况下便能实现回转冲击钻进，达到节约地表水、降低成本、提高钻探效率的目的； 3、设计的球体冲击器构思新颖，克服了同类产品冲击功传递效率低的弊端、且结构简单、经久耐用，可大幅度提高钻探效率、降低钻探成本。

The brake device is preferably a caliper brake device such as a cantilever brake device, a side pull brake device, or a center pull brake device.

制动装置最好是一悬臂制动装置之类的卡钳式制动装置，侧拉式制动装置，或中心拉动式制动装置。

The human heart is the center of the cardiovascular system. Integrated with mechanical, electrical, neural and biochemical properties, the heart is difficult to model, and there is no ideal integral model now. The developed electrical models haven't considered the mechanical properties and blood flow process in the heart; while the mechanical ones have normally deal with the heart in the diastole period, and the electrical activity was simplified too much although some mechanical models have investigated the heart during systole.

心脏是循环系统的核心，它集机、电、神经和生化控制于一体，建模难度很大，目前尚无较理想的统一模型；心脏电生理模型未与心脏的机械动力过程和血液流动过程联系起来；而心脏力学模型大都只研究舒张期的力学特性，即使研究收缩期心脏的力学问题，也往往对心电兴奋做了许多简化假设。

According to the past few years, we deal million Units Mechanical experience, the whole system approach has been striving to excel in our understanding of customers faced the common problem of mechanical and mechanical parts and additional parts of the function of interference after the treatment, we have developed a high standard of mechanical adjustment system of innovation.

根据数年来，我们处理万台机械的经验，整个系统方法已经精进，在我们了解顾客所面对的共同机件问题及械件机能干扰和额外部份处理之后，我们已经发展出具有高水准机械调整革新系统。

According to the past few years , we deal million mechanical experience, the whole system approach has been striving to excel in our understanding of customers faced the common problem of mechanical and mechanical parts and additional parts of the function of interference after the treatment, we have developed a high standard of mechanical innovations adjust system.

根据数年来，我们处理万台机械的经验，整个系统方法已经精进，在我们了解顾客所面对的共同机件问题及械件机能干扰和额外部份处理之后，我们已经发展出具有高水准机械调整革新系统。

In this topic, the dynamic analysis methods for piezoelectric vibrator are studied systematically based on the theoretical model, FEM numerical experimentation and FEM governing equation for given compound-mode vibrator, and some valuable conclusions are obtained. The main work accomplished is summarized as follows: 1.Elaborate the main modeling methods for piezoelectric vibrator and the significance and necessity to study the dynamic characteristics of piezoelectric vibrator which emphasize the urgency of this paper. 2.Take the bending deformation induced by piezoelectric ceramic as example, the energy transfer mechanism of electric energy to mechanical energy are analyzed; the motion and force transfer mechanism are analyzed for the longitudinal-bending vibrator. 3.Based on mode assumption and Hamilton principle, the coupling model of piezoelectric vibrator of linear USM is built; moreover, the equivalent circuit model is obtained and a coupling equation represents the relation between electric parameters and mechanical parameters is derived which provides foundation to match the vibrator and driving circuit. 4.Combine the constitutive equation of piezoelectric ceramic with elastic-dynamical equation, geometric equation in force field and the Maxwell equation in electric field and the corresponding boundary condition equation, the FEM control equation for piezoelectric vibrator of USM to solve dynamic electro-mechanical coupling field is established by employing the principle of virtual displacement. The equation lays the foundation to study the non-linear constitutive equation of piezoelectric ceramic driven by high-power. 5.Define the dynamic indexes of characteristic of vibrator and carry out variable parameters simulation by calculating the model parameters and the electric characteristics of vibrator are simulated according to the equivalent circuit model. By numerical experimentation, the working mode of vibration of vibrator and the shock excitation results of the working frequency band which provides the mode frequency to realize bimodal are analyzed. Detailed calculation of the electro-mechanical coupling field parameters is made by programming the FEM control equation.

本课题从理论模型、有限元数值试验、有限元控制模型等方面以复合振动模式振子为例对超声电机压电振子的动力学特性及其分析方法进行了全面系统地研究，得出了许多有价值的结论，主要概括如下： 1、阐述了目前针对超声电机压电振子的主要建模方法，对压电振子动态特性的研究意义和必要性进行了论述，突出了本文研究内容的迫切性； 2、以压电陶瓷诱发弹性体发生弯曲变形为例，分析了压电陶瓷通过诱发应变来实现机电能量转换的机理；对基于纵弯模式的压电振子的运动及动力传递机理进行了分析； 3、基于模态假定，利用分析动力学的Hamilton原理，建立了面向直线超声电机压电振子的机电耦合动力学模型，并据此建立了压电振子的等效电路模型，导出了电参量与动力学特性参量的耦合方程，为压电振子与驱动电路的匹配提供了依据； 4、从压电陶瓷的本构方程出发，综合力场的弹性动力学方程、几何方程、电场的麦克斯韦方程以及相应的边界条件方程，采用虚位移原理，建立了压电振子动态问题机电耦合场求解的有限元控制方程，为研究其大功率驱动下的非线性本构模型奠定了基础； 5、界定压电振子的动力学特性指标，对压电振子的机电耦合动力学模型参数进行计算及变参数仿真；依据等效电路模型，对压电振子的电学特性进行了仿真分析；通过有限元数值实验，对压电振子工作模态附近的模态振型及工作频率附近的频段进行了激振效果分析，找出了实现模态简并的激振频率；利用有限元控制方程，通过编程计算，对压电振子的力电耦合场参数进行了详细计算，得出了一些有价值的结论。

Through to pumps with the mechanical seal practical application and the theoretical analysis, proposed the mechanical seal actual seal effect not only with the mechanical seal own performance related, the condition which with other spare parts also which provides the condition as well as the seal servosystem provides to have the important relations, therefore pumps the unit product when the design, must for the mechanical seal use provide a good external condition.

通过对泵的机械密封实际应用和理论分析，提出了机械密封的实际密封效果不仅与机械密封本身的业绩有关的条件与其他零件也提供了条件以及印章伺服系统提供有重要关系，因此，泵的单位产品的设计时，必须对机械密封使用提供了一个良好的外部

Yet, Edith says, there was always money in the bank.

但是Edith说，她的银行户口里面总是有钱。

We have created a series of files that resolve this problem--one for each day of the 40 days of purpose.

我们制作一系列的档案去解决这问题---一个为标竿40天中的每一天。