基于Ansys的卧螺过滤离心机液压螺旋差速器的接触非线性分析

液压螺旋差速器是卧式螺旋卸料过滤离心机的关键部件。它将液压技术应用到传统的差速器中,其结构简单、传递扭矩大、差转速无级可调,可充分改善离心机工作转矩的功效执行。分析了差速器运转时柱塞组件的受力关系,同时通过三维建模软件UG建立了差速器的几何模型。利用Hypermesh对几何模型进行了六面体网格划分,通过接触向导建立了柱塞组件之间的接触对,实现了不同部件之间不连续网格的连接;基于扩展拉格朗日算法对柱塞组件进行接触非线性分析,得到了组件的应力云图和路径图,得出在下死点附近处接触应力最大,接触区域符合赫兹接触理论,为进一步研究液压差速器使用寿命提供理论依据。     

全液压牙轮钻机回转系统限压阀组的设计与分析

全液压牙轮钻机在钻进时,对钻杆进行扭矩限制,对整机的安全性具有重要作用。通过对钻杆负载特性分析和回转系统理论研究,设计了以溢流阀和以逻辑插装阀为关键元件的两种阀组,对回转液压系统起到限压作用。采用AMESim软件对两种阀组进行仿真分析,得到回转工况仿真曲线,明确了两种阀下游压力是否对其开口压力产生影响。对逻辑插装阀进行数学建模,分析了其动静态特性。对回转限压系统进行仿真和试验分析,得到牙轮钻机回转液压马达输出扭矩曲线,试验结果验证了仿真分析的正确性和回转限压阀组的可行性,为国产牙轮钻机回转液压系统的设计研发提供理论基础与实践经验。     

直线式数字流体马达的设计与研究

介绍了一种液压执行元件直线式数字流体马达的结构和工作原理,及其在应用中所具有的优势.传统的液压执行元件液压马达和摆动马达输出扭矩和转角,本文介绍的直线式数字流体马达输出力和直线位移,是一种新型的执行元件.     

回路设计:改进型补偿器增加了驱动装置的制动性能

在车辆的驱动装置中,用压力补偿液压马达是实现恒功率控制(高速小扭矩,低速大扭矩)的一种方法。弹簧负载小油缸与液压马达的斜盘机械连接(见图1),液压马达压油口     

非圆行星齿轮液压马达设计系统开发

非圆行星齿轮液压马达是一种新型的低速大扭矩液压马达,其核心机构是一个无系杆、变中心距非圆行星齿轮机构。介绍了非圆行星齿轮液压马达设计的理论依据,引入非线性目标规划方法建立数学模型,避免了反复试凑的繁琐过程,并以34型非圆行星齿轮液压马达的设计为例验证了这一系统的有效性。     

新型偏置式径向柱塞马达特性分析

介绍了一种新型偏置式径向柱塞马达的结构特点。对该马达柱塞的排量、扭矩和运动特性进行理论分析,结果表明该马达具有低速启动性能好、滑靴滑移性能好、运行平稳、噪声低等特点,性能明显优于一般的低速大扭矩马达,且相对于其他类型的液压马达其寿命增加,加工和维修难度降低,除用于普通液压系统外,在一定条件下还可用于纯水液压系统。     

液压绞车的一种恒张力设计

对一种采用比例减压阀和比例溢流阀控制液压马达恒定扭矩的绞车原理进行详细分析。这种方式适用于小功率的绞车,且系统简单、控制容易,可以和其他液压设备共用液压源,减少系统投资。     

液压加载式变速器疲劳试验台测控系统设计

变速器新产品在开发过程中,需要进行一定的载荷循环次加载疲劳寿命试验,以验证内部齿轮、轴、轴承、箱体等零部件以及整体系统的可靠性,液压加载式变速器疲劳寿命试验台是其中重要的试验设备。变速器疲劳寿命试验过程中,扭矩负载一般采用调节液压加载器中的压力进行控制,但温度、机械结构状态等因素会导致扭矩的波动,因此需要对液压加载器中的压力进行实时调节,确保试验扭矩的稳定性。通过试验扭矩PID控制方法和试验系统自动流程控制方法的研究,开发了一套可实现变速器疲劳试验所需的转速转矩自适应控制、试验流程自动控制、试验数据自动采集存储等功能为一体的自动化程度较高的测控系统。疲劳寿命试验结果表明,该测控系统可使液压加载式变速器疲劳寿命试验台具有较高的测控精度及自动化水平,具有广阔的应用前景。     

基于PLC的液压驱动式机械手动作设计

介绍一款采用液压驱动式的机械手,该机械手的特点是结构简单、输出力大、动作平稳,适合于大物件的搬运工作.针对该机械手各动作情况分别对其进行液压回路设计、模拟仿真、PIE顺序控制,并在YZ-02型智能化液压传动实验台上进行机电液一体化模拟实验.实验结果表明:液压驱动式机械手抓力较大,工作性能稳定,通过差动回路可改善其局部运行速度.     

自平衡阀配流式低速大扭矩高水基液压马达的建模与仿真

提出了一种自平衡式高低压阀组配流低速大扭矩高水基液压马达,以满足高水基介质中低速大扭矩工况的需求。首先对其结构及工作原理进行了介绍,进而通过AMESim建立了高水基液压马达的整体模型,以马达的运动特性进行仿真分析。通过仿真研究马达配流阀组不同最大阀芯开度以及负载扭矩等参数对高水基液压马达性能的影响,为自平衡阀配流式低速大扭矩高水基液压马达的设计和制造提供了参考依据。     

含硫钻井液中碳钢的腐蚀及腐蚀疲劳行为

通过滚轮失重,电化学极化曲线测量,氢扩散,腐蚀疲劳,扫描电镜分析,对碳钢在含硫聚合物钻井液中的腐蚀及腐蚀疲劳行为进行了研究。结果表明：硫化物的存在能减缓碳钢的均匀腐蚀,但增大其点蚀敏感性,促进碳钢中氢的扩散进入,从而加速碳钢的腐蚀疲劳破坏。     

Electrochemical characterization and computational fluid dynamics simulation of flow-accelerated corrosion of X65 steel in a CO2-saturated oilfield formation water

The flow-accelerated corrosion (FAC) of an X65 pipeline steel was investigated in a CO₂-saturated formation water by electrochemical measurements and computational fluid dynamics (CFD) simulation on micro-electrodes installed on an impingement jet system. The surface morphology of the electrodes after corrosion test was characterized by scanning electron microscopy. Results demonstrated that the role of fluid hydrodynamics in FAC of the steel depends on its effect on the carbonate corrosion scale formed on the electrode surface. An increasing flow velocity and shear stress would thinner, degrade or even remove completely the scale, increasing corrosion of the steel. An oblique impact of fluid would generally result in a high corrosion rate of the steel. The effect of impact angle on corrosion of the steel is attributed to the distribution of fluid flow field and shear stress on the electrode surface. At the normal impact, a low flow velocity and shear stress and thus a low mass transfer rate would be generated at the centric region. Consequently, a compact corrosion scale can be formed on the electrode surface to protect the steel from corrosion. The highest corrosion rate is observed on micro-electrodes that are adjacent to the center, with the highest flow velocity and shear stress. At the oblique impact angles, the fluid flow velocity and shear stress, and the corrosion rate of the micro-electrodes are higher at the side far away from the nozzle than those at the side close to nozzle. The corrosion activity of the steel electrode located at the center of the sample holder generally increases with the decreasing impact angle due to the enhancing shear effect on the corrosion scale.     

高伸长率QP钢在高应变速率下的力学特性

为研究高伸长率QP钢的动态力学特性,以两种强度级别的QP钢为研究对象,进行准静态和高应变速率下的单向拉伸试验,得到了不同应变速率下的应力-应变曲线。通过对试验数据的分析,研究了应力与应变速率的关系,并提出动态本构模型来描述QP钢的动态力学特性。基于QP980制作的帽型梁零件,使用HyperWorks进行建模,使用LS-DYNA进行模拟轴向压溃过程的计算,并与实际碰撞试验结果进行对比和验证。通过分析发现:QP钢具有明显的应变速率效应,而且应变速率硬化与相对应变速率不呈线性关系。QP钢帽形梁碰撞试验与仿真对比表明,使用修正的Johnson-Cook模型能较好地描述QP钢在不同应变速率下的动态力学特性。     

一种电流变（ER）材料的研制与电流变性能测试

本文对一种电流变液体的颗粒材料和基础液的研制工艺进行探讨，并对其电流变性能进行了测试。     

Thermal stress analysis method considering geometric effect of risers in sand mold casting process

Solidification and fluid flow analysis using computer simulation is a current common practice. There is also a high demand for thermal stress analysis in the casting process because casting engineers want to control the defects related to thermal stresses, such as large deformation and crack generation during casting. The riser system is an essential part of preventing the shrinkage defects in the casting process, and it has a great influence on thermal phenomena. The analysis domain is dramatically expanded by attaching the riser system to a casting product due to its large volume, and it makes FEM mesh generation difficult. However, it is difficult to study and solve the above proposed problem caused by riser system using traditional analysis methods which use single numerical method such as FEM or FDM. In this paper, some research information is presented on the effects of the riser system on thermal stress analysis using a FDM/FEM hybrid method in the casting process simulation. The results show the optimal conditions for stress analysis of the riser model in order to save computation time and memory resources.     

铝电解烟气余热发电系统工质选择

介绍了基于有机朗肯循环的铝电解槽烟气余热发电系统,并对系统工质进行了选择。结果表明:系统工质需具备良好的循环效率、换热性能、化学稳定性、环保性、适中的工作温度和压力、价格低廉以及低的毒性,且宜采用"干流体"或"等熵流体"作为循环工质;经热力计算表明:R123、R134 a和异戊烷三种备选工质中,以R123作为工质时,汽轮机内效率和系统总效率最高,故应优先考虑采用R123作为系统工质。     

胶东金翅岭金矿成矿流体特征及地质意义

为了解胶东金翅岭金矿成矿流体特征,开展流体包裹体研究。结果表明:矿石石英中主要发育H2O-CO2包裹体、富CO2包裹体和H2O溶液包裹体3种类型,成矿流体均一温度、盐度及密度分别为120～362℃,3.2%～9.0%,0.34～0.94 g/m3,为中低温、低盐度及低密度流体;包裹体液相成分阳离子以K+、Na+、Ca2+和Mg2+为主,阴离子以SO42-、Cl-和F-为主;气相成分以H2O、CO2和CH4为主。结合矿区前人研究,认为该成矿流体是多源流体混合并经历水岩反应演变而成。     

The Effects of Low Frequency on the Microstructure and Mechanical Properties of High-Strength Al-Mg Aluminum Alloys by Wire and Double-Pulsed Arc Additive Manufacturing

An innovative and high deposition efficiency process, the double-pulsed arc additive manufacturing process, is used to produce high-strength Al-Mg wall components. This dissertation investigates the electrical parameter acquisition, bead appearance, porosity morphology, microstructure and mechanical properties of additively manufactured high-strength Al-Mg wall components and how these are affected by the low frequency of the double-pulsed arc additive manufacturing process. Then, using this process at different low frequencies of 0, 1, 3, 5, 7 and 9 Hz, multilayer deposition experiments were performed. It can be observed that the deposit porosity is obviously eliminated compared with cold metal transfer (CMT) process. The bead appearance of the deposited aluminum wall varies clearly with low frequencies, and at a low frequency of 3 Hz, its appearance is the best of all. The optical observation of microstructure proves that the average grain size varies significantly with low frequency, and at a low frequency of 1 Hz, it is the smallest. In addition, the deposited wall showed maximum mean microhardness and maximum ultimate tensile strength at a low frequency of 3 Hz. Considering the deposited porosity and mechanical priorities, double-pulsed arc additive manufacturing with a frequency of 3 Hz is more suitable for making high-strength Al-Mg wall components than at other low frequencies.     

水下采油树地面测试单元液压控制系统设计与仿真

对水下采油树进行测试验证可为水下采油树的维修保养提供参考。通过对水下采油树控制系统主参数以及水下采油树测试流程的研究,设计一套水下采油树地面测试单元液压控制系统,水下采油树地面测试单元液压控制系统包括油箱、高压泵回路、水泵回路、蓄能器组、调压回路、接口回路、回油回路等。根据系统主参数及测试要求,对液压控制系统主要元件进行主参数的计算。利用AMESim软件建立水下采油树地面测试单元液压控制系统模型,对模型进行仿真分析。结果表明,所设计的液压控制系统具有良好的控制性和稳定性。     

Grinding of WC-Co cermets using hexagonal boron nitride nano-aerosol

WC-Co cermets (ceramic-metal composites) were ground by a resin bonded diamond grinding wheel using hexagonal boron nitride (hBN) nano-aerosol to improve the grindability. This is a new generation grinding fluid and was produced by dispersing nano-sized hBN platelets in deionized water. Small quantity cooling-lubrication (SQCL) technology was employed to deliver hBN nanofluid in the form of nano-aerosol so that volumetric consumption rate could be kept at a very low value of 200 ml/h. The nanofluid, when separately characterized, demonstrated good lubrication and heat dissipation capability in reference with soluble oil, which is a commonly used cutting fluid for grinding. The superior tribological characteristics of hBN nanofluid were more pronounced at a high sliding speed of 1 m/s, as observed during a ball-on-disc test. However, the beneficial effect of using hBN nanofluid could be extracted more efficiently only in aggressive grinding condition. A clear drop in specific energy, favourable values of residual stress indicate the same. Prevalence of low grinding zone temperature was reflected through low specific energy values and finer but complex chip micromorphology. Overall the aqueous hBN nanofluid was proven to be a high performing grinding fluid suitable for SQCL application and WC-Co cermet grinding.