排序方式: 共有22条查询结果,搜索用时 15 毫秒
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直线导轨的原理及其应用 总被引:2,自引:0,他引:2
在传动领域中,直线导轨一直是关键性产品。随着精密及高速加工技术发展的需要,直线导轨应用范围日益扩大,其可靠的原理、灵活的运用已成为替代传统导轨形式的必然趋势。 相似文献
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王伟志 《运载火箭与返回技术》2007,28(2):1-4,48
文章简要阐述了太阳帆的概念、主要结构和技术,参考美国L’Garde公司的太阳帆展开设计,对涉及的充气及刚化予以概述,为研究分析太阳帆的展开技术提供借鉴。 相似文献
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碳/环氧网格面板-铝蜂窝夹层结构板弯曲刚度试验研究 总被引:1,自引:0,他引:1
根据任务需要 ,对碳 /环氧网格面板 -铝蜂窝夹层结构板进行弯曲刚度性能试验 ,因目前尚无该产品试验标准 ,文章通过对试验方法的研究后 ,参考相应试验标准 ,测试了有关性能数据 ,为材料研究及产品验收提供了可靠的依据 相似文献
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Michael V. Alania Anna Wawrzynczak 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
We show that rigidity spectrum of Forbush decrease (Fd) of galactic cosmic ray (GCR) intensity in September 9–23, 2005 clearly depends on energy. We calculated rigidity spectrum of the Fd based on the neutron monitors and Nagoya muon telescope channels’ data divided in three groups according to their cut off rigidities. We found that temporal changes of rigidity spectrum exponent γ are approximately similar for all cut off rigidity groups, but γ values are the larger the higher are cut off rigidities. We conclude that rigidity spectrum of Fd is hard for lower energy range and is soft for the higher energy range. We believe that an energy dependence of the power law rigidity spectrum of Fd is observed owing to the preferential convection–diffusion mechanism during Fd in September 9–23, 2005. It is a reflection of an influence of the temporal changes of the structure of the interplanetary magnetic field (IMF) turbulence in different range of frequency f during Fd. Particularly, a decisive role in formation of the character of the rigidity spectrum belongs to the changes of the exponent ν of the power spectral density (PSD) of the IMF turbulence (PSD ∝ f−ν). The exponent ν is greater for high frequency region of the IMF turbulence (responsible for scattering of low rigidity particles of GCR), than for low frequency region of the IMF turbulence (being responsible for scattering of higher rigidity particles). Also, we challenge to estimate an existence of slab/2D structure of solar wind turbulence during the Fd in September 9–23, 2005 based on the distribution of average turbulence energy among the IMF’s components. 相似文献
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High-speed axial piston pumps are hydraulic power supplies for electro-hydrostatic actuators(EHAs). The efficiency of a pump directly affects the operating performance of an EHA, and an understanding of the physical phenomena occurring in the cylinder/valve plate interface is essential to investigate energy dissipation. The effects of the splined shaft bending rigidity on the cylinder tilt behaviour in an EHA pump need to be considered, because the deflection and radial expansion of a steel shaft rotating at a high speed cannot be ignored. This paper proposes a new mathematical model to predict the cylinder tilt behaviour by establishing a quantitative relationship between the splined shaft deflection, the cylinder tilt angle, and the tilt azimuth angle. The moments exerted by the splined shaft are included in the equilibrium equation of the cylinder. The effects of solid and hollow splined shafts equipped in an EHA pump prototype are compared at variable speeds of 5000–10,000 r/min. With a weight saving of 29.7%, the hollow shaft is experimentally found to have almost no influence on the volumetric efficiency, but to reduce the mechanical efficiency by 0.6–2.4%. The results agree with the trivial differences of the simulated central gap heights of the interface between the two shafts and the enlargement of the simulated tilt angles by the hollow shaft. The findings could guide designs of the cylinder/valve plate interface and the splined shaft to improve both the efficiency and power density of an EHA pump. 相似文献
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