共查询到20条相似文献,搜索用时 140 毫秒
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张绍军 《机械制造与自动化》2021,50(4):142-145
阐述了农机常用的LS及LUDV负载敏感液压系统的工作原理,利用AMESim仿真软件建立其仿真模型,对两者动态特性及故障现象进行仿真分析.针对LUDV负载敏感液压系统缺点,设计了一种新的支路并联压力切断阀的LUDV负载敏感液压改进系统.仿真结果表明:改进后的LUDV负载敏感系统,能够有效解决系统工作支路卡死或者运动到行程... 相似文献
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在一般夹具增压缸增压回路的设计和应用中,都要附带补油箱(图1),以补偿增压支路工作时产生的微量内泄漏。我们通过实践,设计的压差补油增压缸增压回路,以简单压差补袖支路代替了造价高于其数倍的补油箱,缩小了液压系统的占用空间,使整个液压系统的结构和工作性能更加紧凑。 相似文献
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耿菲 《机械制造与自动化》2023,(6):217-220
以补偿带传输装置的液压系统压力损失、提高带传输装置的稳定性为目标,设计一种能够改善液压系统压力损失的智能补偿系统。阐述带传输装置的结构与工作原理,利用FLuidSIM软件对其进行仿真分析。利用比例换向阀、传感器设计一种具有比例反馈环节的智能压力补偿系统。利用AMESim分别建立普通带传输系统与智能补偿带传输系统的仿真模型。仿真结果表明:在相同的工作压力下,智能补偿系统可对带传输系统进行有效的压力损失补偿,保持带传输装置所需压力的稳定供给。 相似文献
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甘蔗收割机在工作过程中能耗很大。为了减少甘蔗收割机液压系统中的压力损失,该文对采用调速阀和三通压力补偿阀的两种压力补偿系统的静动态特性进行了分析研究。结果表明:三通压力补偿阀系统能够根据负载的变化实时调整系统压力,从而有效地减少甘蔗收割机液压系统在工作过程中的压力损失。在相同工况下,其功率损失比调速阀压力补偿系统少46%左右。 相似文献
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为解决密炼机转子密封处容易出现的渗漏故障,对X(S)M系列密炼机现有的转子端面密封装置方案的液压系统进行了增压方案、增速方案、多缸工作控制技术设计,首先进行在增大压力后的增加速度设计,以补偿因增压导致的工作速度降低,接着考虑4个以900间隔方式排列的液压缸同步动作,在四个点位均匀施压,保证密封效果,以全面提升密炼机液压机构工作性能。 相似文献
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对飞机液压能源系统中存在的压力损失进行了理论分析,并运用AMESim软件建立了飞机液压能源系统元件、管路以及用户的流量压降模型。基于仿真模型对典型飞行阶段液压能源系统各用户支路的压力损失进行仿真计算。该仿真分析模型可用于飞机液压能源系统用户可用压力计算。 相似文献
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对飞机液压能源系统中存在的压力损失进行了理论分析,并运用AMESim软件建立了飞机液压能源系统元件、管路以及用户的流量压降模型。基于仿真模型对典型飞行阶段液压能源系统各用户支路的压力损失进行仿真计算。该仿真分析模型可用于飞机液压能源系统用户可用压力计算。 相似文献
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箔带轧制的三维接触有限元分析 总被引:5,自引:0,他引:5
基于对三维多体接触问题有限元混合法基本原理及接触面的定解条件和判定条件的分析 ,本文将箔带轧机辊系及轧件组成的辊带系统视为三维多体接触问题 ,建立了接触有限元分析模型。对某厂四辊铝箔轧机初轧工况进行了数值计算 ,求得了辊缝内轧制压力的真实分布规律 ,充分揭示了箔带轧制过程中非轧制辊面存在压靠的事实。最后 ,针对来料板凸度对轧件板形的影响进行了有限元仿真分析 ,得出了与轧制规程图分析法一致的结论 相似文献
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ROBERT HANUS JIÍ DAMMER† TOMÁ HOL݆ JAN JAKBEK† STANISLAV POSPÍIL† & RICHARD TYKVA 《Journal of microscopy》2007,226(3):191-194
A method has been developed for routine laboratory visualisation of small‐scale soft tissue by means of transmission X‐ray radioscopy and tomography. Using termites as models, imaging quality with a spatial resolution of about 3 μm was achieved and 3D tomographic reconstruction was demonstrated. A termite worker individual was visualized before and after its metamorphosis towards the soldier caste. The developed methodology represents a non‐invasive and real‐time way of acquiring 3D anatomic data with a high contrast so that it is a promising candidate to become a tool for routine investigations in life sciences. 相似文献
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《Flow Measurement and Instrumentation》1999,10(2):65-77
Four frequently used measurement methods for flow pattern discrimination were identified, developed and implemented in the constructed vertical experimental system. This computer-aided experimental system (CAES) was used to generate all typical flow patterns in vertical flow and measure all chosen dynamic parameters (concentration, pressure, and interfacial phenomenon) simultaneously and in the same space. In this CAES, the flow pattern discrimination system is composed of the application of two different electromagnetic methods (capacitive and resistive), a static pressure method and an optical method. In the reported experimental research on adiabatic air–water flow in a circular vertical channel, results were obtained using a cluster of four chosen measurement systems simultaneously. The results allowed a direct comparison of the ability of each method in terms of application as a flow pattern discriminator. The different abilities of individual methods to detect flow patterns were documented and discussed. 相似文献
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This note presents two experimental techniques for mechanical and electrical characterization of individual nanowires inside a scanning electron microscope (SEM). Tensile testing is realized by transferring a nanowire to a microelectromechanical systems device that stretches the nanowire and measures the elongations and tensile forces. The device consists of an electrostatic actuator and two capacitive sensors, capable of acquiring all measurement data (force and displacement) electronically without relying on electron microscopy imaging. For electrical characterization, four-point probe measurement of individual nanowires is performed automatically by controlling four nanomanipulators with SEM visual feedback. A feedforward controller is incorporated into the control system to improve the response time. This work represents advances in nanomaterial testing and automated nanomanipulation. 相似文献
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Khirod Sankar Das Cynthia Bansara Marwein K. Chanreila L. Nonglait Sudipta Choudhury 《Microscopy research and technique》2022,85(3):956-970
Odontotermes parvidens is a commonly found important pest species of termite that primarily feed on a range of cellulosic sources. In termites, communication among the nestmates is the basis of all their daily activities and the sensory structures present on the sensory appendages play a crucial role in different social behaviors perceiving and processing various signals of the nestmates and external environments. So, it is essential to understand in detail their sensory structures in order to understand the sensory system of the species O. parvidens. Thus, we have studied the antenna which is one of the primary sensory appendages of both soldier and worker individuals of the species to elucidate various antennal sensory structures and their distribution using scanning electron microscopy. Based on the morphological features of various sensilla, we observed seven types of sensilla as sensilla chaetica (subtypes I, II, III, and IV), sensilla trichodea (subtypes I and II), sensilla trichodea curvata (subtypes I and II), sensilla basiconica, sensilla capitula, Böhm bristles, and sensilla campaniformia (subtypes I and II) along with numerous glandular pores on the antenna of soldier and worker castes. We have also discussed the putative functions of all the sensilla observed based on their external morphology and distributional characteristics on the antenna of soldier and worker castes of the species O. parvidens. Furthermore, the abundance of sensillar types on the antenna of both the castes has also been discussed. 相似文献
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The velocity,pressure and temperature distributions of the flow in the gap between hydro-viscous drive friction disks are the key parameters in the design of hydro-viscous drive and angular velocity controller.In the previous works dealing with the flow in the gap between disks in hydro-viscous drive,few authors considered the effect of Coriolis force on the flow.The object of this work is to investigate the flow with consideration of the effects of centrifugal force,Coriolis force and variable viscosity.A simplified mathematical model based on steady and laminar flow is presented.An approximate solution to the simplified mathematical model is obtained by using the iteration method assuming that the fluid viscosity remains constant.Then the model considering the effect of variable viscosity is solved by means of computational fluid dynamics code FLUENT.Numerical results of the flow are obtained.It is found that radial velocity profile diverges from the ideal parabolic curve due to inertial forces and tangential velocity profile is nonlinear due to Coriolis force,and pressure has two possible solution branches.In addition,it is found that variable viscosity plays an important role on pressure profiles which are significantly different from those of fluid with constant viscosity.The experimental device designed for this work consists of two disks,and one of them is fixed.Experimental pressure and temperature of the flow within test rig are obtained.It is shown that the trend of numerical results is in agreement with that of experimental ones.The research provides a theoretical foundation for hydro-viscous drive design. 相似文献