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101.
Akira Ishizaki Kazuhiko Takasaki Shoji Shimomura Kouichi Masaki Kanji Kitazawa 《Electrical Engineering in Japan》1996,116(5):128-137
Although brushless resolvers have been used widely as angular position transducers, they are expensive due to their intricate construction, involving a rotary transformer to supply the exciting coils wound on the rotor poles with the current. It is shown theoretically in this paper that the resolver without rotary transformer or brushes can be realized by simple construction, which consists of the stator core with both 4-poles exciting windings and 2-poles output ones and the rotor core carrying no windings. In this resolver the rotor core has minimum gap at one side and a maximum gap at another side of the diameter. It is characterized by an outer surface form that makes the fluctuation part of gap permeance very in proportion to cos θ, where θ represents the angular position of a point in the air gap with respect to the origin on the rotor, the point of minimum air gap. The method determining the rotor form to embody the aforementioned gap permeance variation is also shown. It has been confirmed not only by simulation but also experiment that the 2-phase output voltages of a model designed based on the theory have sinusoidal waveforms with very small harmonic contents. Moreover, the rotor position detected by processing the output voltages through the conventional resolver/digital converter was within acceptable engineering accuracy. 相似文献
102.
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104.
提出膛口系统是一种准耗散结构,并分析了符合耗散结构的条件,在分析分歧解线性稳定性的基础上,使用高维定态投影解定态分歧解,分歧解与实验结果吻合较好。 相似文献
105.
用于疏通油水井的脉冲放电技术 总被引:1,自引:0,他引:1
评价了各种不同的解堵技术,指出冲击波解堵是一种很有发展前途的技术。介绍了液中脉冲放电产生冲击波的基本原理,并由此研制出了一套井下脉冲放电油水井处理设备样机。通过现场试验,表明用冲击波疏通油井能较好地解除油井污染,提高采收率。 相似文献
106.
A series of nanocomposite thin films, composed of Nd2Fe14B and α-Fe, has been prepared by DC-magnetron sputtering combined ion beam sputtering onto Si (100) substrates. The effects of post annealing on the microstructure and magnetic properties of [NdFeB/α-Fe/NdFeB]-type thin films have been investigated. The X-ray diffraction (XRD) study showed that annealing of the films for 30min at temperatures 550,600,650,700℃ resulted in the appearance of diffraction peaks, characteristic for Nd2Fe14B tetragonal structure, α-Fe and Nd2O3 phases. The investigation using the Vibrating Sample Magnetometer (VSM) with a maximum applied field of 2 T indicated that with the increase of the annealing temperature, the magnetic properties of the multilayer films were improved and reached peak value at 650℃ (Hci=41.72kA·m-1, Mr/Ms=0.4, (BH)max=30.35kJ·m-3), after which the magnetic properties were decreased greatly. Along with the increase of the thickness of α-Fe layer from Tα-Fe16nm, the coercivity Hci, saturation magnetization Ms, and remanence ratio Mr/Ms all declined. As the Atomic Force Microscope (AFM) indicated, after being annealed at 650℃ for 30min, the sample was showed fine surface morphology with grain size 60nm≤dα-Fe≤80nm and 100nm≤dNdFeB≤150nm. 相似文献
107.
通过动态分析和现场测试对一喷气客机的发动机振动作出诊断,发现涡轮叶轮的变柔导致其极转动惯量显著下降,因而改变发动机的动态特性,使其临界转速接近飞机的巡航转速,产生不应有的振动和噪声。文章提出了具体改进方案,已为研制单位采用。 相似文献
108.
Exact solution of elasto-plastic stresses in a metal-matrix composite beam of arbitrary orientation subjected to transverse loads 总被引:1,自引:0,他引:1
An analytical elasto-plastic stress analysis is presented for a metal-matrix composite beam of arbitrary orientation subjected to a single transverse force applied to the free end of the beam and a uniformly distributed load. The material is assumed to be perfectly plastic in the elasto-plastic solution. A composite consisting of stainless-steel-reinforced aluminum was produced for this work. Sample problems are given for various orientation angles. Elastic, elastoplastic and residual normal and shear stresses are calculated. The location of the elasto-plastic boundary of the beam is obtained according to the x coordinates of the beam. 相似文献
109.
采用大电流交流脉冲对非晶Fe78B13Si9合金进行了去应力退火。初步探讨了电脉冲加热对加热速率和该合金内应力释放、退火脆化以及最终软磁性影响的基本规律。结果表明:电脉冲加热可以得到远高于常规退火的加热速率,选择合适工艺参数可使非晶合金内应力释放90%,软磁性(H_c和B_s)达常规退火后的95%以上,与此同时使合金的延性(断裂应变ε_f)维持在0.9以上,从而有望实现非晶合金磁性与延性的合理配合。 相似文献
110.