共查询到20条相似文献，搜索用时 31 毫秒
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ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｎａｔｕｒｅｏｆｓｕｂｓｔｒａｔｅｓｈａｓａｃｒｕｃｉａｌｅｆｆｅｃｔｏｎｂｏｔｈｔｈｅｍｉｃｒｏｓｔｒｕｃｔｕｒｅｏｆｔｈｅｆｉｌｍｓａｎｄｔｈｅｇｒｏｗｔｈｍｅｃｈａｎｉｓｍ (Ｈａｕｓｅｔａｌ.,1 987;Ｋｒｕｇｅｔａｌ.,1 990 ) .Ｆｏｒｉｎｓｔａｎｃｅ,ｔｈｅｔｏｐｓｕｒｆａｃｅｓｏｆｍｅｔａｌｌｉｃｔｈｉｎｆｉｌｍｓｄｅｐｏｓｉｔｅｄｏｎｓｏｌｉｄｓｕｂｓｔｒａｔｅｓｇｅｎｅｒａｌｌｙｈａｖｅａｒｏｕｇｈｓｔｒｕｃｔｕｒｅ ,ｗｈｉｃｈｃａｎｂｅｄｅｓｃｒｉｂｅｄｂ… 相似文献
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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
4.
By an iteration method, the influence of oil film inertia on piston skirt lubrication in a high speed engine is investigated. By alternately solving the Navier-Stocks equations and the Reynolds equation, the new iteration method can trace the variations of velocity field and pressure field with time. Based on this, the mixed-lubrication model suitable for the piston skirt of high engines is proposed. By introducing the inertia coefficient, the new lubrication model includes the inertia term in oil film. The model can be also used to solve for the lubrication performances of a piston skirt in low or medium speed engines and for lubrication problem in general excluding 相似文献
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ZHANG Zhi ming ZHU Li jin YU Jun 《上海大学学报(英文版)》1999,3(3):227-233
Ｎｏｍａｎｃｌａｔｕｒｅ ｂｉｊ,Ｂｉｊ（ｉ,ｊ＝ｘ,ｙ） ｂｅａｒｉｎｇｄａｍｐｉｎｇａｎｄｎｏｎｄｉｍｅｎｓｉｏｎａｌｄａｍｐｉｎｇｃｏｅｆｆｉｃｉｅｎｔｓ,Ｂｉｊ＝ｂｉｊΨ３ｍｉｎ／（２ｌμ） ｃｍｉｎｍｉｎｉｍｕｍｒａｄｉａｌｃｌｅａｒａｎｃｅｏｆｂｅａｒｉｎｇｄｄｉａｍｅｔｅｒｏｆｂｅａｒｉｎｇｅｕ,Ｅｕｅｃｃｅｎｔｒｉｃｉｔｙａｎｄｒｅｌａｔｉｖｅｅｃｃｅｎｔｒｉｃｉｔｙｏｆｍａｓｓｃｅｎｔｅｒｏｆｒｏｔｏｒ,ｒｅｓｐｅｃｔｉｖｅｌｙ,Ｅｕ＝ｅｕ／ｃｍｉｎＦｓｔａｔｉｃｌｏａｄｏｎｂ… 相似文献
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用溶胶-凝胶法制备掺杂改性的二氧化钛溶胶,并选用铝片为载体,以拉膜法制得Ag-Ti-O复合膜片;用XRD、FT-IR等手段对膜片的理化性能进行表征,并以油酸作为目标降解物,分别考察了膜片在紫外光与可见光的光催化氧化性能.结果表明,改性复合膜在紫外光或可见光光照的条件下,均能有效地将附着表面的油类物质氧化分解. 相似文献
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ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｍｉｃｒｏｓｔｒｕｃｔｕｒｅｏｆｔｈｉｎｆｉｌｍｓｐｌａｙｓａｃｒｕ ｃｉａｌｒｏｌｅｉｎａｗｉｄｅｖａｒｉｅｔｙｏｆｐｈｙｓｉｃａｌｐｒｏｃｅｓｓｅｓ.Ｔｈｅｒｅａｒｅｃｌｅａｒｅｖｉｄｅｎｃｅｓｔｈａｔｍａｎｙｐｈｙｓｉｃａｌｐｒｏｐｅｒｔｉｅｓｏｆａｔｈｉｎｆｉｌｍｖａｒｙｄｒａｍａｔｉｃａｌｌｙａｓｉｔｓｍｉｃｒｏｓｔｒｕｃｔｕｒｅｃｈａｎｇｅｓ (Ｈａｕｓｅｔａｌ.,1 987) .Ｆｏｒｉｎｓｔａｎｃｅ,ｒｏｕｇｈｓｕｂｓｔｒａｔｅｓｃａｎｂｅｕｓｅｄｔｏｆａｂｒｉｃ… 相似文献
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Oil-soluble stannous naphthenate (SN) is synthesized by using naphthenatic acid and SnO.And its molecular structure is confirmed by IR and multielement oil analyzer (MOA).The tribological performances of the organotin as lubricant additive are evaluated with a four-ball friction and wear tester.These experiments indicate that the wear scar diameter (WSD) and friction coefficient are diminished while the load-carrying capability increased by comparison with that of base oil.The elemental composition of the boundary lubricating film is examined by means of Auger electron spectroscopy (AES).Synergistic effect is found in the load-carrying capability of the complex of SN and sulfured olefin.The analytical results of AES indicate that the good performance of stannous naphthenate is attributed to the formation of a boundary lubricating film containing Sn on the rubbed surface. 相似文献
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Elastohydrodynamic Lubrication Studies on Effects of Crowning Value in Roller Bearings 总被引：1，自引：0，他引：1
CHENXiao－yang SHENXue－jin 《上海大学学报(英文版)》2001,5(1):76-81
The purpose of this paper is to present a comparison of numerical calculations and experiment results of optical interferometry in finite line contact for the elastohydrodynamic lubrication(EHL)problem of Lundberg‘s profiled cylindrical roller under the conditions of flooded state,moderate load and material parameter.It shows clearly the effects of crowning value on the variations of oil film shape and thickness.The agreement between numerical analysis and experiment results is very good.The results indicate there must be an optimum crowning value that will induce the thickest and most even oil film in EHL state for a given working condition,and this value is larger than the design value in dry contact state for the same working coditiona. 相似文献
10.
Oil-soluble stannous naphthenate (SN) is synthesized by using naphthenatic acid and SnO. And its molecular structure is confirmed by IR and multielement oil analyzer (MOA). The tribological performances of the organotin as lubricant additive are evaluated with a four-ball friction and wear tester. These experiments indicate that the wear scar diameter (WSD) and friction coefficient are diminished while the load-carrying capability increased by comparison with that of base oil. The elemental composition of the boundary lubricating film is examined by means of Auger electron spectroscopy (AES). Synergistic effect is found in the load-carrying capability of the complex of SN and sulfured olefin. The analytical results of AES indicate that the good performance of stannous naphthenate is attributed to the formation of a boundary lubricating film containing Sn on the rubbed surface. 相似文献
11.
The rheological characteristics of the oil film on the rod-seal interface in the sealing zone have a major influence on the behavior of reciprocating seals. Because of the addition of polymers, the viscosity and temperature properties of hydraulic oil have improved and the fluid presents non-Newtonian characteristics. To investigate the influence of these characteristics on seal behavior, a soft elastohydrodynamic lubrication (EHL) numerical model is introduced to simulate a step seal under a mixed lubrication condition. A modified Reynolds equation is derived for calculating the fluid film pressure distribution more accurately. The equation is based on the power law fluid model and Jakobsson-Floberg-Olsson (JFO) cavitation theory. Results are presented to gain insight into the effect of non-Newtonian fluid characteristics on seal behavior, and the simulated results are compared to those of a Newtonian fluid to reveal the seal mechanism. The influence of operating parameters and the seal surface root mean square (RMS) roughness on sealing performance under different power law indexes is also investigated and discussed. 相似文献
12.
Xia A-gen Ye Jian-ting Ye Quan-lin Tao Xiang-ming Jin Jin-sheng Ye Gao-xiang 《浙江大学学报(A卷英文版)》2001,2(4):379-383
A new aluminum thin film percolation system, deposited on glass and silicon wafer surfaces by a vapor deposition method, was
investigated. By using the expansive and mobile behaviors of the silicone oil, the Al films are quenched gradually by the
silicone oil during the deposition process. TheR-I behavior of the film system was studied, and the anomalous conductivity indicated that, at very low current, the hopping
and tunneling effects in the films are much stronger than those of the normal film systems.
Project supported by NSFC (Grant No. 19874016) and the Special Fund of Zhejiang Provincial Natural Science Foundation for
Young Scientists (Grant No. 1997-RC9603). 相似文献
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孙龙林 《深圳职业技术学院学报》2009,8(1):30-32
本文首先介绍了无级变速器滑差率的数学分析,讨论了无级变速器负载对滑差率的影响。在进行试验设计的基础上,进行了不同油压条件下连续加载时滑差率的试验,并利用Matlab软件进行试验数据分析。数据分析表明,无级变速器在合适油压时可以实现弹流润滑,在中低转矩时滑差率可以保持在7％-10．8％,此时可以获得较为理想的传动效率。 相似文献
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采用直流磁控溅射方法在硅油基底上沉积出具有自由支撑边界条件的金属银薄膜系统,研究了银薄膜在大气环境中的表面形貌演化规律及其物理机理。实验发现银薄膜在真空状态下基本稳定,但在大气环境中发生强烈的收缩效应,使得薄膜开裂,其表面覆盖率不断降低。分析表明这一动态演化过程基本满足指数衰减规律,并可用薄膜内应力的不断释放加以解释。随着银薄膜的不断收缩,薄膜表面可呈现出异常丰富的褶皱形貌:在薄膜边界附近呈现基本垂直于边界的直线状条纹结构;而在薄膜中间区域,将形成二次起皱的扭曲状花样和无序网格状褶皱形貌。从单轴应力和双轴应力理论的角度出发,对各类奇特的褶皱形貌进行了细致的分析和讨论。 相似文献
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Nomenclaturex,y,x ·, y·-displacement and velocity of rotor-x,-y,x-·,-y·-displacement and velocity of rotor , di mension less¨x,¨y-acceleration of rotor¨-x,¨-y-acceleration of rotor ,di mensionlessω-rotating speed of rotor-ω-rotating speed of rotor ,di mensionlessx,y,z-Cartesian coordinates-x,-y,-z-Cartesian coordinates ,di mensionless2m-mass of rotorg-acceleration of gravityG-weight of rotor ,di mensionlesse=e2x e2y-mass eccentricity of rotorex,ey-mass eccentricity of rotor in thexan… 相似文献
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唐建东 《深圳职业技术学院学报》2013,12(3):24-26,54
文章探讨了电力变压器油中水分的存在形态及其危害,采用高分子材料聚酰亚胺薄膜的电容式湿度敏感元件原理,实现电力变压器油中微水含量的在线监测．结果表明,该电力变压器油中微水的在线测量变送器的测试结果,与国家标准试验方法一卡尔·费休试剂法一致．电力变压器油中微水含量的在线监测．保证了电力变压器运行安全． 相似文献
18.
Jin Jin-sheng 《浙江大学学报(A卷英文版)》2001,2(4):384-387
The surface morphology and growth mechanism of an aluminum film system deposited on silicone oil surfaces by a vapor depositing
method was investigated by scanning electron microscopy. It was found that the perpendicular fluctuation of the film's bottom
surface was more remarkable than that of the film's top surface. Near the joint between the film on the silicone oil substrate
and the film on the silicon wafer surface on which the silicone oil substrate rested, was a naturally formed anomalous wedge-shaped
wrinkly structure with slopes of 10−4–10−5 rad, whose growth mechanism could be interpreted under the assumption of the thermal expansion behavior of the liquid substrates.
Project supported by NSFC (No. 19874016) and the Special Fund of Zhejiang Provincial Natural Science Foundation for Young
Scientists (Grant No. 1997RC9603). 相似文献
19.
范学增 《天津职业院校联合学报》2010,12(5):6-9
轴向柱塞泵在使用中,经常出现配流副的早期磨损和"烧盘"现象,直接导致轴向柱塞泵磨损失效.通过对轴向柱塞泵配流副润滑油膜厚度的实验研究和综合分析,得出配流副磨损失效的主要原因是油液中的污染物造成的,提出改善配流副工作性能、延长轴向柱塞泵使用寿命的有效措施. 相似文献
20.
Misalignment analysis of journal bearing influenced by asymmetric deflection, based on a simple stepped shaft model 总被引：1，自引：0，他引：1
Zhen-peng He Jun-hong Zhang Wei-song Xie Zhou-yu Li Gui-chang Zhang 《浙江大学学报(A卷英文版)》2012,13(9):647-664
The effects of journal misalignment on a journal bearing caused by an asymmetric rotor structure are presented in this study.A new model considering the asymmetric deflection is applied.Also,the thermo-hydrodynamic of the oil film in the journal bearing and straightforward elasticity theory are considered in the analysis.Based on the structure stiffness equivalent characteristic,a simple stepped shaft can reflect the entire complex structure model.The existing lubrication model,which does not consider this angle component,is not very precise for journal bearings.Film pressure,misalignment angle,velocity field,oil leakage,and temperature field were calculated and compared in the journal bearing analysis.The results indicate that bearing performances are greatly affected by misalignment caused by the asymmetric structure.A simple stepped shaft can effectively represent a misaligned journal bearing in a rotor-bearing system. 相似文献