共查询到20条相似文献,搜索用时 15 毫秒
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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. 相似文献
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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。 相似文献
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Qiaorui Si Patrick Dupont Annie-Claude Bayeul-Lainé Antoine Dazin Olivier Roussette Gérard Bois 《Journal of Mechanical Science and Technology》2016,30(2):549-556
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. 相似文献
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Ihn-Sung Cho Seok-Hyung Oh Jae-Youn Jung 《Journal of Mechanical Science and Technology》2005,19(12):2179-2186
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. 相似文献
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Ihn-Sung Cho Seok-Hyung Oh Kyu-Keun Song Jae-Youn Jung 《Journal of Mechanical Science and Technology》2006,20(10):1716-1721
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. 相似文献
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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. 相似文献
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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。 相似文献
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Qiankun Ma Xuyong Wang Fan Yuan Liangshen Chen Jianfeng Tao Zhonghua Miao 《Journal of Mechanical Science and Technology》2016,30(8):3507-3514
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. 相似文献
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Pakorn Serikitkankul Hiroaki Seki Masatoshi Hikizu Yoshitsugu Kamiya 《Precision Engineering》2007,31(3):202-209
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. 相似文献
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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... 相似文献
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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. 相似文献
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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。 相似文献