液压元件检测系统研究与设计

液压元件的质量是液压系统可靠工作的核心基础,因此对液压元件进行性能检测,对于减少后期设备故障,并为故障分析提供相关依据具有重要意义。拟定了检测系统的整体测试原理方案,液压元件检测系统公称压力为32MPa,测试压力为32MPa,公称流量为160L/min。对该试验台各个组件进行了选型和装配设计,包括各个集成块单元组件的装配设计,最终完成了液压元件检测试验装置中各个集成块、泵站及检测台台架、被试阀阀板等系统检测单元的总体装配设计。在具体方案实施中采用了二维设计与三维设计相结合的方式,以二维设计为主,三维模拟设计为辅,完成了对液压元件检测装置的结构设计。     

装载机液压系统试验台组成及技术要求

装载机液压系统整机性能台架试验,是将装载机元件的台架试验与机载试验进行整合,在实验室内实现装载机整机液压系统(包括泵、阀、缸、油箱、管路和接头等)动载模拟试验。其主要目的是检测整个液压系统的性能参数,可优化和筛选最佳的装载机液压系统方案,研究和验证装载机液压系统的内在性能,为装载机液压系统的开发和改进提供科学准确的试验依据。     

液压元件的测试

各种液压元件,特别是泵、马达、液压缸、阀在制造或修理完了时,都要进行测试,目的是了解液压元件的质量,保证产品寿命,这是非常重要的一环。在液压元件中最主要的元件还是液压泵与液压马达。而它们的测试中最主要的项目又是应用各种液压试验台进行压力、流量、扭矩和转速的测试,快速高效准确地检测各种液压元件的参数大小和性能特征,达到区分液压元件质量好坏,寿命长短。进而判断液压元件可否正常稳定的使用。     

如何使用数控车床加工液压阀体上的圆锥内螺纹

液压阀是构成液压系统的重要元件之一,为了便于加工制作或与液压系统其他元件联接,它的阀体上常常加工有起密封作用的圆锥内螺纹,这些圆锥内螺纹的加工精度直接影响液压阀产品的性能和质量。     

双级换向阀组合的逻辑回路

液压系统工作性能的优劣与液压元件性能和质量及液压系统的结构有关。用双级换向阀组合的逻辑回路,所用元件的品种和数量以及外接管路数少,系统的结构简单紧凑,且能逻辑组合出多种滑阀机能。     

机械多体动力学与液压系统联合仿真

建立机械系统与液压系统之间相互作用的模型,对机械液压系统进行了联合仿真.利用ADAMS液压系统模块建立液压系统回路的框图,然后将其连接到机械系统模型中,选取求解器分析整个系统的性能.得到了系统机械部件和液压元件的性能曲线.对ADAMS液压模块使用中需要注意的一些问题作了介绍.     

超高压液压元件试验台计算机辅助测试系统

以VC 6.0为基本工具,采用面向对象的原理和技术,建立了超高压液压元件试验台的计算机辅助测试系统.在选择高性能的硬件和设计稳定可靠的测控软件基础上,实现了液压元件最高压力70 MPa的性能检测的要求.试验表明系统稳定、可靠、安全和经济.     

掘进机液压元件检测、冲洗多功能装置的研发

为了进一步提高掘进机质量、降低液压系统故障率,需设计一种可用于泵、阀、马达、油缸等液压元件检测、冲洗多功能装置。一方面,可以准确检测、掌握各液压元件的实际参数;另一方面,可以作为车间的液压元件冲洗设备使用。本文中提出了掘进机液压元件检测、冲洗多功能装置的主要技术指标,通过理论计算,确定了该装置的泵、阀、马达、油箱的参数,为下一步的选型、采购工作打下了基础。     

液压系统的组成

一个完整的液压系统由五个部分组成,即动力元件、执行元件、控制元件、辅助元件和液压油。动力元件的作用是将原动机的机械能转换成液体的压力能,指液压系统中的液压泵,它向整个液压系统提供动力。     

叉车用多功能液压试验台

液压系统是内燃平衡重式叉车的重要组成部分,液压系统性能的好坏,液压元件质量的优劣,将直接影响叉车整机的性能。据有关资料统计,在整机故障中,叉车液     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.