共查询到20条相似文献，搜索用时 125 毫秒
1.
严厚顺 《五邑大学学报(社会科学版)》1991,(1)
本文简要地介绍了行星齿轮受到瞬时附加力作用时,各行星齿轮间分布载荷的变化。分别从流体动力学和浮环轴承的动特性两个方面详细地分析和研究了浮环轴承行星齿轮传动的均载原理。 相似文献
2.
本文对高密硬盘系统的静、动特性进行了数字仿真，其中磁头结构为ＩＢＭ３３８０，磁头／磁盘界面的润滑采用多聚脂流体润滑．在流体润滑条件下，磁头飞浮高度可望控制在２０～５０ｎｍ之间，因此在润滑模型中考虑了剪薄效应．应用微扰理论和短轴承理论建立了超薄流体润滑轴承的静、动态方程，并给出了方程的封闭解．在静力学分析的基础上，给出了ＩＢＭ３３８０磁头不同空间姿态的数字仿真．仿真结果表明，随着倾角减小，磁头振动趋于不稳定． 相似文献
3.
李云芳 《山东教育学院学报》2000,15(4):56-57
通过分析浮环所磁力,指出浮环之所以能够跳起或呈悬浮状,交不是因为环上的电流与线圈的电流方向相,反而是由于环上电流与电动势之间的相位差。 相似文献
4.
采用絮凝气浮—过滤工艺处理轴承生产废水。工程实践表明，该工艺处理效果稳定、耐冲击负荷、工艺组合合理。预处理后的废水经气浮一过滤工艺处理后，COD、SS、油的去除率分别为80．62％～84.31％、81．00％～84.39％、89．37％～96．45％，出水完全能达到排放标准。 相似文献
5.
6.
目的：脉冲宽度调制（PWM）变频驱动使轨道交通牵引电机获得了良好的运行性能,但由于输出电压存在共模分量,导致了轴承电压和轴承电流的产生,进而引起轴承早期失效。本文旨在回顾轴承电压根源、轴承电蚀失效模式、轴承电流形成机理、轴承电流共模等效电路、耦合回路阻抗提取和抑制对策等方面的研究现状,并重点围绕轨道交通牵引系统电机及负载接地状况对轴承电压的影响展开全面研究。创新点：1.总结PWM变频系统轴承电流分析与建模方法和抑制对策与效果;2.分析轨道交通牵引系统电机接地配置对轴承电压的影响,并通过共模等效电路模型成功模拟了不同转速下的轴承电压波形,验证了采用接地环和调整系统接地阻抗可以降低轴承电压。方法：1.通过文献搜索和调研,总结PWM变频系统轴承电流的研究方法和思路;2.结合实际轨道交通牵引电机系统接地状况,得到共模等效电路模型和提取回路阻抗参数,并通过仿真模拟与实际测量轴承电压波形,验证模型的正确性;3.通过实际测量,验证接地环和调整系统接地阻抗是否可以降低轴承电压。结论：1.轨道交通牵引系统电机轴承电压与定转子接地阻抗有关,可产生转轴接地型轴承电流;2.通过转轴侧接地共模等效电路,可以模拟... 相似文献
7.
无轴承电机是利用磁悬浮轴承和交流电机结构的相似性,将产生磁悬浮力的磁悬浮轴承绕组置入电机定子,省去了专门的磁悬浮轴承．通过对转矩绕组和悬浮力绕组的解耦控制,使电机的转子同时具有产生转矩和自悬浮的功能．无轴承电机能够实现高速、无摩擦等优良性能,是当前研究的热点之一,无轴承电机悬浮控制系统设计是该研究的关键．本文介绍了无轴承电机悬浮控制的基本原理,设计了基于转矩绕组转子磁场定向的悬浮控制系统． 相似文献
8.
林丹阳 《宁德师专学报(自然科学版)》2013,25(3):298-300
广东罗定一水电厂的SFW2000—6／1430水轮发电机在运行时发现导轴承温升过高．通过对设备各方面参数认真分析、计算;对导轴承进行了详细检查,找到原因并加以处理．经过处理轴承温升回到正常状态,保证了机组的安全稳定运行． 相似文献
9.
10.
对C6-3．43／0．49型汽轮机推力轴承前轴承轴瓦损坏原因做了分析,并提出了改进措施． 相似文献
11.
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｓｉｎｃｅ 1990 ,ａｎｉｍｐｏｒｔａｎｔｄｉｓｃｏｖｅｒｙｉｎｒｏｔｏｒ ｈｙｄｒｏ ｄｙｎａｍｉｃｂｅａｒｉｎｇｓｙｓｔｅｍｄｙｎａｍｉｃｓｉｓｔｈｅｃｏｕｐｌｅｄａｃ ｔｉｏｎｏｆｔｈｒｕｓｔｂｅａｒｉｎｇｕｐｏｎｔｈｅｌａｔｅｒａｌｖｉｂｒａｔｉｏｎｉｎａｒｏｔｏｒｓｙｓｔｅｍ .Ｉｎｔｈｅ ｐｉｏｎｅｅｒｉｎｇｒｅｓｅａｒｃｈｏｆＭｉｔｔｗｏｌｌｅｎｅｔａｌ .( 1990 ) [1] ,ａｓｅｒｉｅｓｏｆｒｏｔｏｒ ｄｙｎａｍ ｉｃｃｏｅｆｆｉｃｉｅｎｔｓｏｆｔｈｒｕｓｔｍａｇｎｅ… 相似文献
12.
On the basis of the current sheet model, a new analytical solution for permanent magnet （PM） bearings is developed. Compared with analytical methods based on the coupling energy model and the magnetic dipole model, the proposed one is more physically intuitive and convenient for engineering designers. According to the analytical model, the thrust characteristics of a novel PM thrust bearing is studied and verified by finite element analysis （FEA）. In the proposed thrust bearing configuration, the rotor is composed of stacked PM tings with alternative axial magnetization directions, and the stator with alternative radial magnetization directions while copper rings are used to separate adjacent PM rings. A prototype PM thrust bearing with the proposed configuration is designed and fabricated. The performances of the PM thrust beating are experimentally validated. It is shown that the calculation accuracy of the presented analytical solution is satisfying. 相似文献
13.
针对滚动轴承振动信号的特点,从分形原理出发,利用分形维数的概念,对由滚动轴承故障产生的非平稳、非线性信号进行了分形特征的定量描述.试验结果表明,滚动轴承不同故障出现时,其分形维数明显不同.因此,可以利用分形维数有效地诊断出滚动轴承的故障. 相似文献
14.
Three-ring gear reducer , an internal gear planetarytransmission, claims many advantages , including largetransmission ratio, high loading capacity, and compactvolume[1].However ,there still exist some disadvantagesinits application.One is the unbalanced … 相似文献
15.
Reaction thrust of water jet for conical nozzles 总被引：1，自引：0，他引：1
Clear knowledge on the reaction thrust of water jet is valuable for better design of water jet propulsion system. In
this paper, theoretical, numerical and experimental studies were carried out to investigate the effects of the nozzle geometry
as well as the inlet conditions on the reaction thrust of water jet. Comparison analyses reveal that the reaction thrust has a
direct proportional relationship with the product of the inlet pressure, the square of flow rate and two-thirds power exponent
of the input power. The results also indicate that the diameter of the cylinder column for the conical nozzle has great influence
on the reaction thrust characteristics. In addition, the best values of the half cone angle and the cylinder column length exist
to make the reaction thrust reach its maximum under the same inlet conditions． 相似文献
this paper, theoretical, numerical and experimental studies were carried out to investigate the effects of the nozzle geometry
as well as the inlet conditions on the reaction thrust of water jet. Comparison analyses reveal that the reaction thrust has a
direct proportional relationship with the product of the inlet pressure, the square of flow rate and two-thirds power exponent
of the input power. The results also indicate that the diameter of the cylinder column for the conical nozzle has great influence
on the reaction thrust characteristics. In addition, the best values of the half cone angle and the cylinder column length exist
to make the reaction thrust reach its maximum under the same inlet conditions． 相似文献
16.
The shapes and geometrical parameters of nozzles are key factors for fluidics. The relationship among the reaction thrust, flow rate pressure, diameter do and length L of a cylinder nozzle is analyzed theoretically. The simulation of the flow field characteristics was conducted via the FLUENT computational fluid dynamics package. Effects of the inlet conditions and the nozzle dimensions on the reaction thrust of a water jet were addressed particularly. The reaction thrust experiments were performed on a custom-designed test apparatus. The experimental results reveal that a） the nozzle diameter and the inlet conditions exert great influence on the water jet reaction thrust; and b） for L≤4d0, where the nozzle is treated as a thin plate-orifice, the reaction thrust is independent of nozzle length; for L〉4d0, where the nozzle is treated as a long orifice, the reaction thrust can reach maximum under the condition of a certain flow rate. These findings lay a theoretical foundation for the design of nozzles and have significant value, especially for the future development of high-oressure water-let orooulsion technology. 相似文献
17.
The effects of journal misalignment on the transient flow of a finite grooved journal bearing are presented in this study.
A new 3D computational fluid dynamics (CFD) analysis method is applied. Also, the quasi-coupling calculation of transient
fluid dynamics of oil film in journal bearing and rotor dynamics is considered in the analysis. Based on the structured mesh,
a new approach for mesh movement is proposed to update the mesh volume when the journal moves during the fluid dynamics simulation
of an oil film. Existing dynamic mesh models provided by FLUENT are not suitable for the transient oil flow in journal bearings.
The movement of the journal is obtained by solving the moving equations of the rotor-bearing system with the calculated film
pressure as the boundary condition of the load. The data exchange between fluid dynamics and rotor dynamics is realized by
data files. Results obtained from the CFD model were consistent with previous experimental results on misaligned journal bearings.
Film pressure, oil film force, friction torque, misalignment moment and attitude angle were calculated and compared for misaligned
and aligned journal bearings. The results indicate that bearing performances are greatly affected by misalignment which is
caused by unbalanced excitation, and the CFD method based on the fluid-structure interaction (FSI) technique can effectively
predict the transient flow field of a misaligned journal bearing in a rotor-bearing system. 相似文献
18.
通过对实船轴系可测试轴段进行横向自由振动模态测试,得到其固有频率及振型。并在有限元软件ANSYS中进行仿真,利用测试得到的固有频率及振型来确定轴系的边界参数,即轴系支撑刚度,得到一个正确的仿真模型。之后,根据振动模态分析原理进行中间轴承的位置优化。在一定螺旋桨激励力下,可将中间轴轴承振动位移减小一个数量级。 相似文献
19.
Chen Han-lin Zeng Hua-sheng Shen Xiao-hua Yang Shu-feng Zhang Guoc-cheng Xiao Wen-jiao Li Ji-liang Zhao Dong-dong 《浙江大学学报(A卷英文版)》2000,1(4):431-436
The authors’ analysis of the chemical components and sedimentary characteristics of the well developed Triassic strata in
the southeastern part of western Kunlun Shan led them to conclude that the sediments comprise a set of typical deep-water
to semi-deep-water flysch that formed in the passive continental margin of the Qiangtang Block. This suit of strata had undergone
strong deformation giving rise to a SW-thrusting duplex, imbricate fans, high-angle thrust fault, recumbent fold, SW-inverted
fold, etc.. The deformational intensity weakens gradually southeastward. This is a foreland fold and thrust belt caused by
the collision between the Qiangtang Block and the island are on the southern margin of the the Tarim Plate at the end of late
Triassic.
The sedimentary and deformational characteristics of the Triassic strata were used to reconstruct the evolution of this foreland
fold and thrust belt as proposed below. Before the end of Triassic, this region was a passive continental margin in the north
of the Qiangtang Block. The end of Triassic to Jurassic was a stage of thrusting, folding, uplifting and development of the
foreland basin. The evolution of the fold and thrust was completed in Cretaceous.
Project supported by NSFC (49872073) and Key Project of NSFC. 相似文献
20.
分析了磁悬浮轴承电磁力与其电流和转子位移非线性关系产生的原因,结合国内外文献资料,主要从磁轴承偏置磁场以及本质非线性两方面对磁悬浮轴承力与电流及其位移关系线性化策略进行概述。 相似文献