对VUP系列叶片泵压力振摆的试验研究

通过对270台VUP系列叶片泵的试验研究,该文总结出了泵内零件尺寸对压力振摆的影响.并在现有工艺水平的条件下,对装配工序辅以人工研磨的方式来控制零部件的尺寸,最终使产品性能达到行业标准.企业采纳该文所得出的一些规律或经验之后,可以不用引进精密机床就能成功控制产品的各项性能.     

湿式多片式制动器带排转矩研究

针对一种重型车辆采用的湿式多片式制动器,分析研究了其在分离状态下的带排转矩,讨论了转速,润滑油温,润滑油流量对带排的影响,最后提出了改进措施。     

Static pressure recovery analysis in the vane island diffuser of a centrifugal pump

The overall performance of a vane-island type diffuser of a centrifugal pump model was obtained by means of directional probe traverses. These measurements were performed in an air model of a real hydraulic pump for five volume flow rates. Directional probe traverses are performed with a classical three-hole probe to cover most of the complete inlet section of the diffuser from hub to shroud and from pressure to suction side. Existing Particle image velocimetry (PIV) measurement results are also used to compare probe measurement results between the inlet and outlet throats of vane island diffuser at mid-span. Some assistance from already existing unsteady calculation, including leakage effects, is used to evaluate the numerical approach capability and to correctly define the mean initial conditions at impeller’s outlet section. Pressure recovery and the measured total pressure loss levels inside this particular vane diffuser geometry are then calculated. Detailed analysis of the flow structure at the inlet section of the vane island diffuser is presented to focus on pressure evolution inside the entire diffuser section for different flow rates. The combined effects of incidence angle and blockage distributions along hub to shroud direction are found to play an important role on loss distribution in such a diffuser.     

The lubrication characteristics of the vane tip under inlet pressure boundary conditions for an oil hydraulic vane pump

The lubrication modes of line contact between the vane and the camring in an oil hydraulic vane pump have been investigated. First, variations of the radial acting force of a vane were calculated from previously measured results of the dynamic internal pressure in four chambers surrounding a vane. Next, distinctions of the lubrication modes were made using Hooke’s chart, which represents an improvement over Johnson’s chart. Finally, the influence of boundary conditions in the lubrication region on fluid film lubrication was examined by calculating film pressure distributions. The results show that the lubrication modes of the vane tip are a rigidvariable viscosity region. This region discharges pressure higher than 7 MPa, and exerts a great influence on oil film pressure in the large arc section due to the Piezo-viscous effect.     

The Lubrication characteristics of the vane tip under pressure boundary condition of oil hydraulic vane pump

The Lubrication Mode of line contacts between the vane and the camring in an oil hydraulic vane pump has been investigated. First, the variations of the radial force of a vane were calculated from previous measurements of dynamic internal pressure in four chambers surrounding a vane. Next, the lubrication modes were distinguished with Hooke’s chart, which is an improvement over Johnson’s chart. Finally, the influence of the boundary conditions in the lubrication region on the fluid film lubrication was examined by calculating the film pressure distributions. The results showed that the lubrication mode of the vane tip exists in the rigidvariable-viscosity region, and that discharge pressure higher than 7 MPa greatly affects the oil film pressure in the small and the large arc section because of the Piezo-viscous effect.     

转缸驱动转子滑片压缩机运动分析

介绍了一种新型结构滑片压缩机的结构特点和工作原理，该新结构压缩机与传统滑片压缩机相比。改善了低速性能，具有更低的振动噪声和摩擦损失等优势。建立了机构模型，并分析了该压缩机的运动规律。     

利用直接识别法建立制动器压力和力矩传递函数

高度可调铁塔的组装是该型铁塔使用的技术难题,提出高度可调铁塔液压同步提升控制系统的设计思路,以ZM110高度可调铁塔的施工技术为研究对象,完成了同步提升系统的机械结构、液压回路以及PLC控制单元。该系统可对铁塔进行原地提升,提高高度可调铁塔的施工效率。     

The Influence of the vane on the lubrication characteristics between the vane and the rolling piston of a rotary compressor

The rolling piston type rotary compressor has been widely used for refrigeration and air-conditioning systems due to its compactness and high-speed operation. The present analysis is part of a research program directed toward maximizing the advantages of refrigerant compressors. The study of lubrication characteristics in the critical sliding component is essential for the design of refrigerant compressors. Therefore, theoretical investigation of the lubrication characteristics of a rotary compressor being used for refrigeration and air-conditioning systems was investigated. The Newton-Raphson method was used for a partial elastohydrodynamic lubrication analysis between the vane and the rolling piston of a rotary compressor. The results demonstrated that the vane thickness and the center line position of the vane significantly influenced the friction force and the energy loss between the vane and the rolling piston.     

减振槽型式对转向叶片泵配流冲击的影响

动力转向叶片泵的噪声对汽车舒适性产生不利影响，其中配流冲击是叶片泵的重要噪声源。优化减振槽结构是降低配流冲击的有效措施。从分析叶片工作腔压力变化出发，建立了预升压微分方程，计算了三种减振槽的预升压和压力梯度，给出了预升压和压力梯度曲线。结果表明，采用变截面和等截面减振槽并联而成的复合结构可以显著地降低配流冲击。     

叶片泵反转危害的案例浅析

介绍了叶片泵叶轮断裂故障发生的过程，进行了原因分析及结论判定，总结了防范措施。     

叶片泵与齿轮泵的组合设计及研究

该文对液压系统的两种动力元件即齿轮泵及叶片泵进行分析整合,设计出一种新型泵,不仅改善齿轮泵工作容积密封不严、径向力不平衡、困油现象、噪声变大,压力小,吸油难的缺点,也改善了传统叶片泵结构复杂排量较小的缺点,以及泵在运转时由于叶片与轴位置固定可能出现刮卡现象,叶片与定子表面磨损等缺点,使之能解决上述问题并能满足现代对大型液压设备的需要。     

Effects of the friction coefficient on the torque characteristics of a hydraulic cam-rotor vane motor

The friction coefficient between the vane and the slot is one of the most critical factors that affects the performance of a continuous rotary hydraulic cam-rotor vane motor. To study the effects of this coefficient on the torque characteristics of the motor, the mathematical model for the normal force and the disturbing torque between the cam rotors and the vanes of the motor was established by analyzing the forces exerted on the vanes. The mathematical model was simulated with MATLAB, and simulation results show that an increase in the friction coefficient would simultaneously decrease the normal force and increase the disturbing torque, which would negatively affect the performance of the motor. Further experimental research indicated that the low-speed performance of the hydraulic cam-rotor motor was significantly improved when the friction coefficient was reduced by controlling the parallelism tolerance, flatness and roughness between the vanes and the slots.     

Study on effects of negative driving torque in servomotor drivers

Many applications, such as elevators, electric cars and robotic applications, require a servomotor driver capable of controlling a motor to drive its load with either positive or negative driving torque. The negative driving torque is defined as torque applied to a load in the reverse direction of motor rotation. In a servomotor driver with a switching amplifier, when the motor drives its load with negative driving torque, effects of negative driving torque might damage the servomotor driver and complicate dynamic characteristics of the servomotor system. Thus, in order to investigate effects of the negative driving torque in servomotor drivers, this paper uses the numerical simulation that combines the simulation of a control system with that of electronic circuits. The simulation results show that the negative driving torque is required for decelerating and compensating disturbance. During decelerating and compensating disturbance, the pulse-width modulation (PWM) amplifier of a servomotor driver will generate regenerative current that flows from the motor back into the power supply, and then makes the power supply voltage rise.     

油液中气泡含量对高压叶片泵工作腔油液压力和叶片受力的影响

考虑绝热过程中气泡含量与油液弹性模量的关系,建立高压子母叶片泵工作腔油液预升压过程中油液压力与气泡含量关系的数学模型,得到不同气泡含量下叶片泵预升压过程中油液压力和排油区叶片受力随转子转角变化的曲线。     

轴流泵和导叶式混流泵模型研究及工程应用

轴流泵和导叶式混流泵,主要用于水利、市政、电厂和船坞等部门的供排水,在核电、舰船的喷水推进方面也得到了重要应用。为了给南水北调等工程提供优秀水力模型,进行了轴流泵、贯流泵、双向泵和导叶式混流泵水力模型的试验研究,这些模型已在南水北调等工程中得到了应用,并用其中一些模型进行了几个具体泵站的装置模型试验。介绍了泵（段）模型和泵装置模型的试验结果,分析泵段特性和装置特性之间的关系,为大型泵站水泵选型提供参考。     

液力变矩器泵轮承压面的流场建模与仿真

以纳维—斯托克斯方程为基础,利用粘性液体在叶片承压面处的速度场的已知条件,可以求解液力变矩器叶片承压面处的速度场、压力场、旋度场、应力场。这样就可以得到流场的解析解,即精确解,避免传统处理上的一些缺陷。     

基于喉部参数控制的离心泵导叶扩散度研究

为研究导叶扩散段无量纲参数对离心泵水力性能的影响,通过控制导叶喉部参数设计出5种导叶扩散度方案,采用雷诺时均N-S方程和RNGκ-ε湍流模型对离心泵进行全流场计算,对比分析了不同扩散度方案对上游叶轮、导叶本身以及下游压水室水力性能的影响,并验证了数值分析的可靠性.研究表明:导叶扩散度对上游叶轮水力性能较大,叶轮效率随导...     

基于制动力矩的ABS整车控制方法的研究

提出了一种基于整车的控制方法,首先根据制动压力进行道路自动识别,然后根据路况自动调整左右两侧车轮的制动力之差,以保证车辆制动时的方向稳定性.结合14自由度的虚拟样机整车模型,分别在对接路面和分离路面上进行基于ADAMS/Simulink的联合仿真制动模拟试验.结果表明该方法能够较好的识别路面状态,使车辆在兼顾其制动距离与时间的前提下提高其直线制动的方向稳定性,为一些基于路面状态的汽车主动控制策略提供了条件.     

制动气室有效承压面积的探讨

我国拖拉机挂车气制动系统执行机构主要采用膜片式制动气室,对拖拉机挂车机组气制动系的制动性能完全满足强制性国家标准GB16151-2008《农业机械运行安全技术条件》和GB7258-2004《机动车运行安全技术条件》中规定要求的膜片式制动气室有效承压面积进行理论分析和试验研究后,得出膜片式制动气室有效承压面积不仅与几何尺寸和气压有关,还与工作行程有关.试验按照国家行业标准JB/T9840.1-1998《拖拉机挂车气制动系统制动气室技术条件》进行,找到了膜片式制动气室有效承压面积的变化规律.膜片式制动气室有效承压面积不是一个固定不变的数值.指出了不同型式的膜片式制动气室推杆有效工作行程范围.     

一种液压转盘输出扭矩测量装置的设计

不压井修井机上的液压转盘需要测量其输出扭矩和在相应扭矩下卡瓦牙的夹持性能,市场上没有专门的测量设备,如果要设备厂家专门设计价格太高,鉴于这个因素,我们自己设计一套测量扭矩的工装,很好的测量出转盘的扭矩和夹持机构的夹持性能,一是节约了成本,二是为新产品的开发提供了有利支持。