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January 30,2015
Volume 8,Issue 2
Pages -
Subject Area:Hydraulic Structures,Environmental Water Conservancy

Title: Three-dimensional temperature field investigation of axial flow blood pump permanent magnet motors

Authors: TAN Zhuo, TAN Jianping, LIU Yunlong
PP: 192-200
Abstract: According to computational fluid dynamics and heat transfer theory, mathematical model coupled with temperature field of axial flow blood pump was built. The loss type of axial flow blood pump was analyzed, and drive motor stator winding modeling was simplified, heat coefficient of pump shell was derived as well. The axial blood pump three-dimensional finite element model was established by ANSYS Workbench, which steady-state thermal analysis was taken for the global FSI heat transfer model and the whole blood pump temperature distribution was obtained. The results showed that the blood pump maximum temperature rise was 0.922℃ at rated speed, which could meet the body’s temperature requirements of blood pump. Based on the proposed thermal field model, effect of the stator losses, the rotation speed of pump as well as the air gap thermal conductivity between stator and pump housing on the temperature of the blood pump were analyzed, which could help optimize the design of blood pump in future applications.
Keywords: other subject of mechanical engineering; axial flow blood pump; fluid-solid couple; temperature field; associated analysis

Title: Study on double-engine hydraulic transmission system of the large dump truck

Authors: ZHANG Ning, JIAO Shengjie
PP: 186-191
Abstract: In order to solve the design and manufacture problem of the transmission system of the large mining dump truck, the current drive system mode of the large mining dump truck was analyzed and compared, the problems existing in the transmission way were pointed out, and the idea that the dump truck could be driven by the double-engine was put forward. Three types of the hydraulic transmission system were presented and the process of the hydraulic transmission system and its advantages and disadvantages were worked out in details. Every solution have met the design requirements, which will provide a theoretical basis for the hydraulic transmission system of the large mining dump truck.
Keywords: special mechanical engineering; mining dump truck; transmission; single-axle drive; all-wheel drive

Title: Study on power matching of single-engine sweeper

Authors: LEI Weiwei, ZHOU Ji, QU Xiaohe, LIU Ming, SONG Yonggang
PP: 181-185
Abstract: Aiming at the need of road cleaning, based on the theoretical analysis, combined with relevant research results, power matching problem of single-engine sweeper was studied. In this sweeper, mechanical transmission was adopted for the work device, while hydraulic transmission was adopted for the chassis moving system. In this paper, some major pieces of power in single-engine sweeper was analyzed and a control strategy was put forward. Meanwhile, it’s found that the utilization rate of engine power was not satisfied when we took the transmission scheme in this sweeper as previously mentioned. So further improvement of the performance scheme should be made for the study of single-engine sweeper.
Keywords: special mechanical engineering; single-engine; sweeper; power matching

Title: Finite element analysis on friction-induced noise for plate type of water-lubricated rubber bearing

Authors: ZHOU Yi, ZHANG Heng, LIU Fang
PP: 175-180
Abstract: Friction noise analysis model of plate type of water-lubricated bearing was built using ABAQUS software. By using the analysis method of finite element complex eigenvalue theory and based on the positive or negative of complex eigenvalue real part, the possibility of bearing system generating noise were estimated. If the real part eigenvalue was positive, the noises would be generated. Through the analysis of finite element, unstable tendency of the bearing system under different parameters was obtained, including the friction coefficient, groove radius and shape. The results showed that the friction coefficient had great influence on the friction noise of water-lubricated bearing. Groove radius and shape also had a certain impact on noise prediction results.
Keywords: mechanical friction, wear and lubrication; water-lubricated rubber bearing; finite element; friction-induced noise

Title: Design and experiment of real-time monitoring system for motor bearing fault

Authors: WANG Jin, GE Dalong, ZHAO Shuaishuai, CHEN Chengjun
PP: 170-174
Abstract: In order to monitor motor bearing fault, a bearing fault monitoring system was designed. Vibration sensor, current sensor, speed sensor and temperature sensor were installed in different locations of the motor. Acquisition interface circuit was designed by STM32F3 series processor, and the collected information was sent to PC by CAN field-bus. PC processing software was designed accordingly. By processing the date collected when the motor running, real-time monitoring realized. In this paper, the related content of this system was introduced and the experiment with artificial damaged bearing was conducted to verify the system, which would be of great value in practice.
Keywords: mechanical parts and transmission; bearing fault diagnosis; vibration frequency; real-time monitoring

Title: Research on electrochemical machining of inner helical gear

Authors: CHEN Yuanlong, CHEN Zhen, CAO Yuming, JING Guangtao, CHEN Zhengwen
PP: 165-169
Abstract: Due to the complexity of tooth shape, thin-walled and material hardness of inner helical gear with micro-segment profile, conventional method is difficult to carry out on the processing. However, electrochemical machining (ECM) can solve this problem well. A set of process equipment, including tooling and fixture, cathode parts, conductive system and electrolyte system was designed and manufactured. After designing the experiment plan, single factor experiment and orthogonal experiment were used to analyze the experimental data and the optimal process parameter combination was obtained. The results showed that the machining gear precision met the requirements of high efficiency, good surface quality, no mechanical residual stress and no need for subsequent processing.
Keywords: mechanical manufacturing and automation; inner helical gear with micro-segment profile; pulse electrochemical machining; process equipment

Title: Development of a new five axis three-dimensional rapid prototyping machine

Authors: HU Qing, HAO Jingbin, LIU Chuliang, LAI Zhenyu, JI Hansong
PP: 157-164
Abstract: In this paper, the improved design of the traditional desktop printer was proposed based on the principle of five-axis CNC machine tool. Problems of the influence of staircase effect and support structure on printing quality were solved by the new five-axis rapid prototyping machine. The implement method, programmed algorithm and machine design were illustrated and analyzed in detail. The design can effectively improve the printing efficiency and printing quality.
Keywords: manufacturing processes and equipment; rapid prototyping machine; staircase effect; skeleton extraction; space coordinate transformation

Title: Numerical simulation of fan speed influence on flow fields in the preheating section of a hot air system for film production

Authors: WANG Jian, CHEN Dongjie, YANG Lu, LIU Liang, TANG Bilian
PP: 150-156
Abstract: The quality of plastic film depended on the stability of the hot air system of film production line. In order to optimize the uniformity and stability of the flow fields in the hot air system, the flow fields of the preheating section of a hot air system were numerically simulated in this paper. Two different fan speeds (1 200, 1 600 r/min) were used when the temperature of the hot air was 175℃. The changes of the velocity, pressure and temperature were investigated. The results showed that decreasing fan speed could improve the uniformity of the velocity and temperature in the middle cushion layer, but it will reduce the uniformity of the pressure.
Keywords: principle and method of mechanical design; film production line; hot air system; fan speed; numerical simulation

Title: Research on vibration characteristics of 3K-I planetary gear system used in space manipulator

Authors: ZHAO Yongqiang, LIU Ming
PP: 144-149
Abstract: The modified tortional dynamic model was built by using lumped parameter method. The free vibration characteristics were analyzed based on the model. Planet vibration mode f, planet vibration mode g and coulpling vibration mode were revealed by the relation between the natural frequencies and vibration mode, which is the theory basis of the dynamic analysis.
Keywords: principle and method of mechanical design; 3K-I planetary gear; modified torsional model; vibration characteristics

Title: Study on improvement of the dynamic analysis method of hydraulic system

Authors: WANG Yong, ZHANG Teng, YUN Jiongming
PP: 137-143
Abstract: Aiming at avoiding the shortcomings of traditional methods, an improved dynamic analysis method of hydraulic system was proposed and the flow chart was presented. By taking hydraulic system of an hydraulic punch press as an example, improved program was put forward from two aspects of system and component. The co-simulation analysis results of the improved hydraulic system showed that working frequency of the hydraulic system was significantly improved.
Keywords: mechanical design; hydraulic system; dynamic analysis method; co-simulation

Title: Research on agricultural machine and agronomy of rain-fed potato planted by micro-ridge side with plastic cover

Authors: CUI Yachao, JIA Liguo, QIN Yonglin, DU Wenliang, FAN Mingshou
PP: 131-136
Abstract: In the course of rain-fed potato plantation by micro-ridge side with plastic cover, high labor intensity was needed and soil sampling was difficult but it got low production efficiency. By combining agricultural machinery with agronomy, the ridge distance, the ridge height and the space were adjusted. A new plant agronomic measure was designed in this paper, which was popularized in large rain-fed area and would be of great significance in improving the mechanization level and economic performance of micro-ridge side planting with plastic cover in dry land.
Keywords: mechanical design; rain-fed potato; micro-ridge and plastic cover; side planting; agricultural machinery and agronomy

Title: Research on isotropic loading and unloading triaxial tests of cement sand and gravel material

Authors: CAI Xin, YANG Jie, GUO Xingwen
PP: 127-130
Abstract: Aiming to study stress and deformation characteristics in the isotropic loading and unloading process, the isotropic loading and unloading triaxial tests of cement sand and gravel material with different cement contents （60, 80 kg/m3）were carried out. The experimental results showed that the hysteresis loop of cement sand and gravel material was formed in the process of isotropic loading and unloading triaxial tests and becomes larger with increased stress. At the same time, the shape of these hysteresis loops was geometrically similar. According to these results, we focused on the analysis of the elastic and inelastic characteristic in the process of isotropic loading and unloading triaxial tests of cement sand and gravel material, which could contribute to the establishment of the elastic-plastic model of such material.
Keywords: hydraulic structures; cement sand and gravel material; isotropic loading and unloading triaxial tests; elastic-plastic model

Title: Concrete dam real time safety diagnosis method and diagnosis system

Authors: YANG Yang, FAN Guangya, XU Haifeng
PP: 120-126
Abstract: In order to effectively obtain real-time security status of the dam in a variety of complex geological conditions and climatic environment, analysis model for dam prototype observation data of various types was built. A variety of diagnostic methods of safety of concrete dam were proposed, and concrete dam safety multi-criteria diagnosis system was constructed. The safety diagnosis software for concrete dam was established and applied to analyze one of the concrete dams.
Keywords: hydraulic structures; concrete dam; safety diagnosis; system

Title: Research on the producing mechanism and exchange processes of total dissolved gas through the dam

Authors: FU Xiaoli, SHEN Chao
PP: 114-119
Abstract: To explore the total dissolved gas(TDG) exchanging processes and changing patterns, this paper focused on physical processes governing the producing mechanism and TDG exchange at forebays, spillways, powerhouses, stilling basins and tailwater channels based on studies on field observations. Similarities was drawn between these general processes and the existing TDG exchange properties at a lot of dams. The TDG concentration on the stilling basin and spillway where the most complicated flow pattern happened was relevant to spillway flow, spillway jet, powerhouse operation and tailwater channel flow. The surviving conditions of fishes passing through the dams will benefit from it.
Keywords: environmental water conservancy; total dissolved gas; spillway release; field observation; optimal operation

Title: Review of influence on the bank stability under wet and dry cycles of water rocks

Authors: LIU Xinrong, ZHANG Liang
PP: 104-113
Abstract: A brief review of the water-rock interaction(WRI) history since the late 1950s and the branch structure of WRI was introduced. From geotechnical and geological engineering point of view, the significant results of the test methods for wet and dry cycle of water-rock, variation of rock mechanics parameter, the deterioration mechanism and damage model of rock and the stability of reservoir bank were reviewed. Perspectives concerning the following research fields where innovative results may occur were discussed inclucding the stability of reservoir bank under complex conditions of water-heat-force field coupling, quantitative study of water-rock chemical kinetics weakening as well as research on reservoir bank stability under the rainfall and water flow dynamics influence.
Keywords: other subject of basic science of water conservancy project; water-rock interaction; review; wet and dry cycle; coupling; reservoir bank

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