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现阶段闭式液压系统已经成为液压行业的发展趋势之一,通过分析闭式液压系统的原理,阐述了补油泵在闭式液压系统中的作用.通过分析计算系统的发热功率,根据系统的热平衡得到补油泵流量的设计公式,对闭式液压系统的补油泵及油箱的设计有指导作用. 相似文献
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芦苇笋采收机工作过程中需调节采摘工作头与地面之间的距离,文中针对采收机工作头位置调节的问题,设计了一种举升俯仰机构液压系统。通过对整机作业过程进行描述,并对采收机举升俯仰机构的原理进行分析,绘制举升俯仰机构的液压系统原理图,并对关键部件进行理论计算,得出液压执行元件的相关参数与各关键液压元器件的型号和参数。随后在AMESim软件中对液压执行元件在不同工况下进行动态特性研究,并对作业过程进行仿真,得出举升俯仰机构液压缸的流量、速度和位移曲线,最后,对芦苇笋采收机举升俯仰机构的液压系统进行安装调试并在田间运行试验。在田间性能试验过程中,系统运行平稳,通过公式计算可得举升液压缸及俯仰液压缸上升速度偏差分别为11.5%,10%,下降速度偏差分别为9.2%,10.5%,与地面的距离偏差分别为5.7%,7.9%,从实际作业效果上看,系统完全满足芦苇笋采收机作业要求。 相似文献
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针对液压系统使用的一种双作用安全阀,根据其需要达到的性能和参数进行了分析,确定了进行试验需要的液压系统方案,并从试验台电机、泵、液压方向控制、压力控制、管路和油箱等的几个方面进行试验台的设计计算,为试验系统制造提供了相应的技术依据。 相似文献
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在深入分析掘进钻车液压系统污染源的基础上,从液压系统设计、装配、使用维护等方面对液压系统的污染控制进行了探讨,重点提出了闭式压力油箱结构和一种针对液压凿岩机的供气回路;研究结果对其他矿用工程机械液压系统的设计具有借鉴意义。 相似文献
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从轴瓦内封闭式螺旋油槽的使用特点和高效加工方法出发,介绍了加工内封闭式螺旋油槽时数控系统和加工机床的选择及其参数调整法,详细分析了数控加工工艺中刀具的选择、对刀点的确定和进、退刀方式的确定,并介绍了实现消除进、退刀痕迹及编程的技巧。其实际加工效果良好,能满足加工需求,同时有效地提高了加工质量和加工效率。 相似文献
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随着社会的不断发展,空调的应用越来越普遍,膨胀水箱是闭式空调系统十分重要的组成部分,关系着整个空调的稳定性。主要对膨胀水箱在空调水系统的工作原理和安装进行了分析和研究,并对膨胀水箱的容积进行了计算,为膨胀水箱在空调系统中的利用提供了科学合理的依据。 相似文献
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《Measurement》2016
In this paper, an adaptive fuzzy control (AFC) system is proposed to realize level position control of two coupled water tanks, often encountered in practical process control. The fuzzy control system includes an adaptive model identifier and controller. The gains of AFC are obtained by using the fuzzy identifier model which is defined by real system outputs and control inputs. The parameters of fuzzy identifier model are adjusted online by using recursive least square algorithm. Because the controller has a recursive form it treats model uncertainties and external disturbances in an implicit way. Thus there is no need to specify uncertainty and disturbances for this controller design in advance. A well-tuned conventional proportional integral (PI) controller is also applied to the two coupled tank system for comparison with the AFC system. Experimentation of the coupled tank system is realized in two different configurations, namely configuration #1 and configuration #2 respectively. In configuration #1, the water level in the top tank is controlled by a pump. In configuration #2, the water level in the bottom tank is controlled by the water flow coming out of the top tank. Experimental results prove that the AFC shows better trajectory tracking performance than PI controller in that the plant transient responses to the desired output changes have shorter settling time and smaller magnitude overshot/undershoot. Robustness of the AFC with respect to water level variation and capability to eliminate external disturbances are also achieved. Experimental results show that AFC is a strong and a practical choice for liquid level control. 相似文献
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Natural convection in a liquefied natural gas storage tank, which is caused by the heat absorption from the surrounding environment, is studied numerically by solving the conservation equations for mass, momentum, and energy with a commercial computational fluid dynamics code, FLUENT. The present numerical results show that the interfacial heat transfer rate, which is directly related to the boil-offgas generation rate, strongly depends on the liquid-solid contact area. The contribution of the heat transfer rate from the vapor region is negligible compared with that from the liquid region. The effects of the external convection coefficient, tank size, and tank shape on the flow and temperature fields and on the interfacial heat flux are quantified. 相似文献
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P. Madhavasarma 《仪器科学与技术》2013,41(4):420-431
Abstract A 40 liter spherical tank with varying time delay was subjected to open loop analysis using a step response technique with sodium chloride solution as tracer. The experimental data was adequately represented by a first order plus dead time (FOPDT) model with an error of less than five percent. These model parameters were used to generate Smith Predictor controller, IMC controller, and IMC PID controller using MATLAB. For closed loop control of the process based on rise time, settling time, overshoot, peaktime, decay ratio, and ISE, it was found that the IMCPID controller is better suited for this process. 相似文献
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为明晰齿轮马达密闭介质的制动机理及其制动性能的最大化措施,从齿轮副的啮合过程出发,由马达内介质作用的液压转矩等于马达外的负载转矩,推导出负载驱动转速的定量公式,并就制动性能最大化对齿形参数执行最优化设计。结果表明:啮合点的位置不同,负载驱动转速也不同,其中,最小困油位置处的最高,节点啮合处的最低;齿形参数对负载驱动转速的影响很大,案例优化前后的制动性能提高了31.2%~46.1%;负载转矩与马达内客观存在的泄漏途径为驱动转速产生的外因与内因,齿轮较小的宽径比和齿顶高系数能有效控制马达内泄漏等。研究成果为高质量齿轮马达的进一步研究与开发,提供一定的理论依据。 相似文献
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Large pressure equipment needs to be tested regularly to ensure safe operation;wall-climbing robots can carry the necessary tools to inspect spherical tanks,such as cameras and non-destructive testing equipment.However,a wall-climbing robot inside a spherical tank cannot be accurately positioned owing to the particularity of the spheri-cal tank structure.This paper proposes a passive support and positioning mechanism fixed in a spherical tank to improve the adsorption capacity and positioning accuracy of the inspection robot.The main body of the mechanism was designed as a truss composed of carbon fiber telescopic rods and can work in spherical tanks with diameters of 4.6-15.7 m.The structural strength,stiffness,and stability of the mechanism are analyzed via force and deformation simulations.By constructing a mathematical model of the support and positioning mechanism,the influence of struc-tural deformation on the supporting capacity is analyzed and calculated.The robot positioning method based on the support and positioning mechanism can effectively locate the robot inside a spherical tank.Experiments verified the support performance and robot positioning accuracy of the mechanism.This research proposes an auxiliary support and positioning mechanism for a detection robot inside a spherical tank,which can effectively improve the position-ing accuracy of the robot and meet the robotic inspection requirements. 相似文献