共查询到20条相似文献，搜索用时 31 毫秒
1.
杨清华 《邢台职业技术学院学报》2014,(5):80-83
本文中给出了由一对磁环轴向充磁组成的轴向永磁轴承,并采用等效电流法计算两磁环之间的轴向力,阐明了永磁轴承在某一方向不稳定的原因。根据特定的永磁轴承实体模型,给出了其动力学方程,并对轴向的非线性运动方程用迦辽金法求出了方程的解析解。通过利用matlab软件进行仿真,证明了特定的永磁轴承在小气隙内磁环可以获得小振幅的稳定模态。 相似文献
2.
Analytical solutions for the two-dimensional magnetic fields in disc-type permanent magnet machines 总被引：1，自引：1，他引：0
Zhang Yuejin Xie Guodong 《上海大学学报(英文版)》1998,2(4):290-294
Ｍａｇｎｅｔｉｃ Ｆｉｅｌｄｓ ｉｎ Ｄｉｓｃ－Ｔｙｐｅ Ｐｅｒｍａｎｅｎｔ Ｍａｇｎｅｔ ＭａｃｈｉｎｅｓTX１ＩｎｔｒｏｄｕｃｔｉｏｎＡｔｗｏ－ｄｉｍｅｎｓｉｏｎａｌ（２Ｄ）ａｎａｌｙｔｉｃａｌｍｅｔｈｏｄｆｏｒｃｏｍ－ｐｕｔｉｎｇｔｈｅａｘｉａｌ... 相似文献
3.
WANG Xiao jing ZHANG Zhi ming ZHANG Guo xian 《上海大学学报(英文版)》1999,3(3):234-237
１ Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｗｉｔｈｔｈｅｉｎｃｒｅａｓｉｎｇｃａｐａｃｉｔｙｏｆｈｙｄｒｏｇｅｎｅｒａｔｏｒｓａｎｄｔｈｅｒｅｌｅｖａｎｔｌｙｉｎｃｒｅａｓｉｎｇｓｉｚｅａｎｄｌｏａｄｉｎｇｏｆｔｈｒｕｓｔｂｅａｒｉｎｇｓ,ｔｈｅｃｏｎｆｉｇｕｒａｔｉｏｎｏｆｐａｄｓｕｐｐｏｒｔｅｄｏｎａｓｉｎｇｌｅｐｉｖｏｔｈａｓｍｏｒｅａｎｄｍｏｒｅｄｉｆｆｉｃｕｌｔｙｉｎｍｅｅｔｉｎｇａｌｌｔｈｅｄｅｍａｎｄｓｉｎｒｅａｌｏｐｅｒａｔｉｏｎｃｏｎｄｉｔｉｏｎｓ．Ｔｈｅｃｏｎｆｉｇｕｒａｔｉｏｎ… 相似文献
4.
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｓｉｎｃｅ 1990 ,ａｎｉｍｐｏｒｔａｎｔｄｉｓｃｏｖｅｒｙｉｎｒｏｔｏｒ ｈｙｄｒｏ ｄｙｎａｍｉｃｂｅａｒｉｎｇｓｙｓｔｅｍｄｙｎａｍｉｃｓｉｓｔｈｅｃｏｕｐｌｅｄａｃ ｔｉｏｎｏｆｔｈｒｕｓｔｂｅａｒｉｎｇｕｐｏｎｔｈｅｌａｔｅｒａｌｖｉｂｒａｔｉｏｎｉｎａｒｏｔｏｒｓｙｓｔｅｍ .Ｉｎｔｈｅ ｐｉｏｎｅｅｒｉｎｇｒｅｓｅａｒｃｈｏｆＭｉｔｔｗｏｌｌｅｎｅｔａｌ .( 1990 ) [1] ,ａｓｅｒｉｅｓｏｆｒｏｔｏｒ ｄｙｎａｍ ｉｃｃｏｅｆｆｉｃｉｅｎｔｓｏｆｔｈｒｕｓｔｍａｇｎｅ… 相似文献
5.
表面磁钢永磁无刷电机电磁转矩的解析法分析 总被引：1，自引：0，他引：1
With the air gap magnetic field distribution of surface mounted permanent magnet （PM） motors obtained using an analytical technique, the instantaneous electromagnetic torque and its corresponding components are investigated with the Maxwell stress tensor method. Accurate results can easily be achieved using the proposed method without using the tedious finite element analysis （FEA）. In this paper, the electromagnetic torque of a surface mounted PM motor with two phases energized is decomposed into four torque components. This technique is useful not only for the design and optimization of the permanent magnet motor, but also for the choice of control strategy. 相似文献
6.
With the air gap magnetic field distribution of surface mounted permanent magnet (PM) motors obtained using an analytical technique, the instantaneous electromagnetic torque and its corresponding components are investigated with the Maxwell stress tensor method. Accurate results can easily be achieved using the proposed method without using the tedious finite element analysis (FEA). In this paper, the electromagnetic torque of a surface mounted PM motor with two phases energized is decomposed into four torque components. This technique is useful not only for the design and optimization of the permanent magnet motor, but also for the choice of control strategy. 相似文献
7.
The dynamic response of a flexible spinning vehicle with the varying thrust was investigated. The varying thrustwas modeled as a series of simple harmonic components superimposed on a constant thrust. The analytical solutions forlongitudinal motion were obtained by combining the motion equations and boundary conditions, and then, the transversebending of rocket was examined solved by considering a coupled forcing vibration with varying parameters. Numericalsolutions for a rocket with end-varying thrust were studied. It is shown that the lateral vibrations and motion attitudes ofrocket depend on the frequencies of varying thrust to great extent, and an important phenomenon, beating, maybe take place.The proposed approach is more accurate and efficient in comparison to those standard numerical techniques. 相似文献
8.
Yi-cong GAO Yi-xiong FENG Jian-rong TAN 《浙江大学学报(A卷英文版)》2014,15(11):862-872
研究目的：为复杂机械产品提供满足整机可靠性指标和维护成本指标的预防性维护方案多准则规划方法。创新要点：1.分析了检查、维修、更换等对复杂机械产品零部件工作寿命变化的作用机理;2.提出了复杂机械产品预防性维护多准则规划方法。研究方法：1.基于非完美维修理论,建立不同模式下零件间工作寿命模型,定义维修效能因子,表征检查、维修、更换对零件寿命的影响;2.通过求解获得复杂机械产品指定时间区间的预防性维护方案,根据零部件工作寿命,采取维修和更换等预防性维护措施,减少零部件故障的发生。重要结论：零部件的预防性维护次数与其故障因子相关;机械产品尤其是复杂机械产品实施定期预防性维护能够减少或消除故障的发生。 相似文献
9.
A novel elevator door driven by tubular permanent magnet linear synchronous motor （TPMLSM） is presented. This TPMLSM applies axial magnet array topology of the secondary rod, air-cored armature windings and slotless structure of the forcer to improve the stability of the thrust. The influence of two major dimensions, the pitch and radius of the permanent magnet （PM）, on magnetic field was studied and the best values were given by the finite element analysis （FEA）. The magnetic field, back EMF and thrust of the motor were analyzed and the PM size was optimized to reduce the harmonic components of the magnetic field and improve the performance of the motor. Predicted results are validated by the experiment. It is shown that the performance of the motor and the novel elevator door system is satisfying. 相似文献
10.
深埋圆形富水隧道应力与位移的弹塑性解 总被引：1，自引：0，他引：1
研究目的：推导获得深埋圆形富水隧道应力场与位移场分布的弹塑性解析解。创新要点：皋于弹性力学厚壁圆筒受均布压力的拉姆解答和Mohr—Coulomb屈服条件,推导了考虑渗流作用和应力释放时含衬砌深埋隧道的弹塑性解,并采用FLAC3D有限差分程序验证了其正确性。研究方法：通过理论分析建立考虑渗流作用和应力释放的含衬砌深埋圆形隧道的解析模型（图1）,然后推导了基于Mohr-Coulomb屈服准则的隧道同岩与衬砌渗流场、位移场和应力场计算的弹塑性解析公式,并通过数值模拟程序（图2）验证了推导公式的正确性。重要结论：基于前人研究皋础,推导获得了深埋富水隧道应力与位移场分布的理论解析解,并通过数值模拟方法验证了其正确性。该解析解一方面可以用于深埋高水头隧道的预设计,如预测隧道周围的水压力、应力场和位移场分布规律,另一方面可用于校核大型复杂数值模型的正确性。 相似文献
11.
The transverse injection flow field has an important impact on the flowpath design of scramjet engines. At present a combination of the transverse injection scheme and any other flame holder has been widely employed in hypersonic propulsion systems to promote the mixing process between the fuel and the supersonic freestream; combustion efficiency has been improved thereby, as well as engine thrust. Research on mixing techniques for the transverse injection flow field is summarized from four aspects, namely the jet-to-crossflow pressure ratio, the geometric configuration of the injection port, the number of injection ports, and the injection angle. In conclusion, urgent investigations of mixing techniques of the transverse injection flow field are pro- posed, especiaUy data mining in the quantitative analytical results for transverse injection flow field, based on results from multi-objective design optimization theory. 相似文献
12.
以弹性金属塑料瓦推力轴承为研究对象,设计推力轴承试验台,研究弹性金属塑料瓦与普通金属轴瓦的性能区别,并为研究弹性金属塑料瓦推力轴承的起动过程作试验准备. 相似文献
13.
We presented a numerical examination of the effect of microtexturing negative rings’ structure on the tribological performance of parallel bearing couples’ cell. Three mcirotexturing rings, which are circle, square and ellipse, were chosen and the analysis model were established. We used the Reynolds equation coupled with finite difference method and successive over relaxation Gauss-Seidel iterative method to solve the Newtonian flow’s hydrodynamics within a bearing couple. The effect of texture density and radius ratio (thickness) of the microtexturing rings were investigated on the tribological performance under the similar operating conditions. The numerical simulation reveals that: 1) The microtexturing rings’ structure can homogenize the local pressure much uniformly within the bearing cell. 2) The tribological performance is determined mainly by the microtexturing rings’ geometry and texture density, and the thickness of the rings’ structure can help to change the quantitative values. 3) The square and circle rings’s microtexturing surface can slightly improve the frictional performance with the bearing cells’ gap, while the ellipse ring’s surface may decrease the frictional performance. 4) The ellipse rings’ microtexturing surface can achieve the minimum spacing gap but the maximum friction coefficient of the bearing couple, and then the circle and square rings’ structure take the second and third place, respectively 相似文献
14.
Based on the characteristics of an L-shaped column composed of concrete-filled square steel tubes, the axial compression experiment and nonlinear finite element analysis were carried out to study the mechanical property of the L-shaped column. The load-displacement curve for the L-shaped column, the deflection and load-strain curves for the mono columns were obtained by the axial compression experiment. The results show that the L-shaped column exhibits a flexural-torsional buckling failure mode. The numerical simulation by the finite element analysis shows that the bearing capacity and failure mode are in accordance with those of the axial compression experiment and the feasi- bility of the finite element analysis is proved. For the calculation of the bearing capacity of the L-shaped column com- posed of concrete-filled square steel tubes, an analytical method is proposed based on the theory of the elastic stability and spatial truss model. The results of the analytical method are in good agreement with those of the axial compression experiment and the finite element analysis. 相似文献
15.
无取向硅钢要求沿材料的所有方向都具有均匀的磁性能,即要求磁各向异性要尽可能地小,以便为旋转电机提供理想的磁性能。通过试验测试了3.0%Si无取向硅钢不同方向的磁感,铁损和磁致伸缩系数。实验结果表明55°和125°磁化轴为最难磁化轴,而0°和180°磁化轴为最易磁化轴,铁损的变化规律与磁致伸缩系数一致,即90°最大,0°和180°最小,采用相应的理论和数学模型能较好地进行模拟和解释实验结果。 相似文献
16.
锚泊辅助动力定位是结合了锚泊定位系统和动力定位系统的一种新型位置控制系统。锚泊辅助动力定位系统是最节能且最稳定的定位系统,在国际海洋工程领域具有广阔的应用前景。本文着眼于目前国际上对于锚泊辅助动力定位系统的研究状况,分别从理论计算和模型试验两个角度对其研究进展进行阐述,同时介绍了我国在此领域的研究进展,进一步提出了对于强化相关研究工作的建议。 相似文献
17.
研究目的：分析深埋隧道的塌方机制并推导塌方体形状曲线的解析表达式。创新要点：基于霍克-布朗准则,采用泛函突变理论推导得到了深埋隧道塌方体形状曲线的解析表达式,并据此分析了围岩参数变化对塌方体形状的影响规律。研究方法：通过理论分析建立深埋圆形隧道的解析模型（图1）,采用泛函突变理论推导基于霍克-布朗准则的隧道塌方体形状曲线解析表达式,并研究围岩参数变化对塌方体形状的影响规律（图3和4,表2）。通过与自然拱理论和模型试验结果的对比（图5–7）验证本文解析解的正确性。重要结论：采用泛函突变理论推导了基于霍克-布朗准则的深埋隧道塌方体形状曲线解析表达式。该解析表达式简洁直观,不仅可以预测无支护条件下隧道的塌落体尺寸,还可以估算塌落围岩作用于衬砌上的荷载。 相似文献
18.
The National Swimming Center built for the 2008Beijing Olympic Games applies the polyhedron spatialframe structure, which is based on the foam physicstheory[1]. Its simple geometry is a square box of 170m×170 m×29 m. It can hold 17 000 people, theroof o… 相似文献
19.
The pipe configuration and internal loads along the pipeline during the pipeline laying process have long been the focus of engineers. Most researchers simplify the seabed to be rigid and the water to be calm, ignoring the pipe embedment into the seabed and the influence of ocean currents. In this paper, a novel numerical approach is proposed for the laying of pipelines in the so-called J-lay method, taking into account the importance of both pipe embedment and ocean currents. The pipeline is divided into two parts, one part suspended in water, and the other laid on the seabed. The continuity of the two parts at the touch down point （TDP） is guaranteed to make a whole. The feasibility of the model is proved by the comparison between the present model and an analytical model, which shows good agreement in both pipeline configuration and bending moment distribution. Finally, para- metric study was performed to consider the influence of current velocity, water depth, top inclination angle, and seabed stiffness, and conclusions are drawn. 相似文献
20.
为研究多种随机因素对一类两部件串联系统预防性维修决策的影响,提出一种拟周期预防性维修策略优化模型．假设预防性维修对部件1为完整修,对部件2为保养,预防性活动在实施区间内根据动态计划随机进行;意外更换和预防性更换的竞争结果决定系统的更换,当部件2发生严重故障时引发系统的意外更换,当预防性维修次数达到设定的阈值Ⅳ时实施预防性更换．通过建模和优化分析,给出了最优预防性维修实施区间和最佳维修次数的求解算法,并通过数值案例对模型的优化过程和参数的敏感性做了说明．分析结果表明,在满足实际生产需求的前提下,尽可能地缩短实施区间能提高系统的平均运行时间和降低系统的长期运行成本率． 相似文献