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Island-type texture was fabricated on two types of pico-sliders using plasma etching and ion beam etching. Laser–Doppler interferometry was used to investigate the vibrations of textured and untextured pico-sliders in near-contact situations. Lubricant depletion on the disk surface was investigated in the slider wear tracks using scanning ellipsometry (Surface Reflectance Analyzer (SRA)). The results show that slider in-plane and out-of-plane vibrations were reduced as a consequence of the texture on the slider surface. In addition, lubricant depletion on the disk surface was found to be less severe for textured sliders than for untextured sliders at flying heights below 10 nm. 相似文献
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The authors propose a novel slider design. The tri-pad slider has three separate air bearing surfaces, one in the front of the slider and the other two in the back of the slider. This design permits the optimization of the air bearing stiffness and flying attitude without changing the minimum flying height. It can minimize the effect of skew angle on the flying height, and offers ample room for a larger size thin film head element. Samples were fabricated and flying characteristics at several velocities, as well as the dynamic flying stability, were investigated. 相似文献
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A simulation approach that relies on an analysis of the flow patterns closest to an air bearing surface (ABS) was used to
predict the lubricant accumulation on the ABS of a head slider. The lubricant accumulation patterns obtained through the simulation
were in good agreement with experimental results and with our experimental apparatus. We used this method to study and analyze
flow pattern droplets close to the trailing edge of a number of sliders and found that there was a reverse flow from the slider’s
trailing edge on both sides of the trailing pad and behind the read/write element, which could result in a lubricant accumulation
on the slider surface close to the trailing edge of a slider and thus lead a transient slider vibration and magnetic-signal
loss in a hard disk drive. Further simulations and analyses revealed that the reverse flow is dependent on the depth of slider
surface on adjacent to the trailing edge of the slider, and that if the depth is less than a critical depth, which is dependent
on the velocity of the disk, the reverse flow could be eliminated. On the basis of these findings, we propose a new ABS design
concept for effectively suppressing the reverse flow of lubricants from the trailing edge of the slider. In this concept,
the slider has a “smooth flow pad” and the depths of outlet recesses are specified as being smaller than the critical depth.
It was confirmed by both simulation and experiment that lube accumulation on the slider surface is obviously decreased and
the reliability of a hard disk drive with this air bearing design is consequently improved. 相似文献
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Czeslaw M. Rodkiewicz 《摩擦学汇刊》2013,56(2):178-183
Thrust bearing characteristics are examined in the motion generated by the accelerating slider. The selected case is the situation where the fluid within the lubricating film initially is at rest and at time zero the infinitely long slider assumes a velocity which is a function of time. Numerical solutions to the governing differential equations are obtained for the case of constant but arbitrary acceleration and for the case of acceleration proportional to time. The corresponding previously published analytical solutions are compared with those numerical results. 相似文献
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大功率空气静压轴承电主轴 总被引:3,自引:1,他引:3
介绍自行研究设计的空气静压轴承高频电主轴设计上的特点:一是空气轴承采用“全支承”结构,显著地提高轴承的承载能力和刚度;二是较国内同类型产品其变频电机的输出功率显著增大,可适应高效磨削的要求。 相似文献
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滑块压缩机滑块与直线轴承间相对滑动的分析 总被引:1,自引:0,他引:1
对滑块压缩机中滑块与直线轴承间的相对滑动现象进行了分析,建立了圆柱湔子滚动模型,给滑块与直线轴承间无相对滑动时所需最小预紧力的计算公式。 相似文献
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A three-dimensional (3D) thermohydrodynamic (THD) model for air foil thrust bearings (AFTBs) is presented. The nonisothermal Reynolds equation is solved using pressure boundary conditions at the cooling air plenum considering local temperature-dependent viscosity and density. Air film temperature is calculated using the 3D energy equation with thermal boundary conditions at the top foil, thrust runner, and top foil’s leading edge. The cooling air plenum distributes the cooling air to multiple radially arranged cooling channels. The plenum temperature and pressure are found from mass and energy balance equations applied to the plenum. Temperature fields of the top foil, bump foils, thrust disc runner, bearing plate, and cooling air channels are also solved through appropriate energy balance equations with their surroundings. A robust computational algorithm with multiple iteration loops was developed to find all the temperature fields. THD analyses were performed for AFTB with outer radius of 50 mm up to 100,000 rpm. As the cooling air source pressure is increased, the plenum pressure also increases and its temperature decreases due to more cooling capacity. However, cooling effectiveness is not necessarily proportional to the pressure because the flow residence time inside the cooling channels is inversely proportional to the pressure. The analyses show that the thrust disc temperature is a parabolic function with speed, and thermal expansions of the thrust disc and thrust plates contribute to the most significant driving force of thermal instability. Optimum cooling air pressure was found around 12,500 Pa for the proposed AFTB design at the reference simulation condition. 相似文献
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静压气浮导轨采用气体润滑,具有无摩擦、热变形小、寿命长等优点,且气膜的误差均化作用显著提高了其运动精度,满足三坐标测量机高精度、高平稳运动需求。为探究三坐标测量机中静压气浮导轨滑块的承载性能,建立了矩形气浮滑块结构模型,滑块内置小孔节流型气浮垫,运用COMSOL有限元仿真软件对其气浮静态承载特性进行仿真分析,验证了结构设计的合理性。 相似文献
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E. Kingsbury 《摩擦学汇刊》2013,56(3):259-262
Pivoting slips are calculated for the ball-race and ball-ball contacts in a retainerless bearing. The calculation is kinematic, ignoring all inertial loadings. Pure spin and uniform precession of the balls are considered. Pivoting slip magnitudes are compared with several other kinds of slip which have previously been reported in an R4 size bearing. 相似文献
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通过对轴承的运动进行分析,寻求轴承零件的转速与轴承几何尺寸之间的关系,进而推导出轴承接触角与轴承零件转速的关系,通过检测轴承零件转速间接测量轴承接触角。 相似文献
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针对高速轴承中现存的失效问题,采用有限元方法,利用ANSYS Workbench软件,建立高速滚动轴承三维分析模型。在合理的边界条件下,对模型中各个滚动体与轴承内、外圈接触应力和变形进行数值计算,从而得到各个滚动体与轴承内、外圈的接触应力及变形量,以及3号滚动体与1号滚动体的对比图,得出了相同增量下各个滚动体的接触应力和接触变形的变化情况。同一力下不同滚动体的接触面积变化情况。计算结果与赫兹理论解接近一致,表明建立的模型及边界条件合理,准确。求解得到的各个滚动体的接触应力和变形为滚动轴承的失效形式分析与设计提供理论依据。 相似文献
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The experimental investigation was carried out for dry contact tribosystems to elucidate the ascertained, yet uncharacterized, relationship between the coefficient of friction, η and apparent contact geometry in sliders. This paper presents the results of various experimentally evaluated slider pad width to length ratios, B/L (L is signified with direction of motion), while maintaining the unit loading constant. The empirical data is intended to provide guidance in design and in theoretical prediction of optimum bearing geometry for solid/powder lubricated systems. In this experiment, a liquid lubricant, two different dry powders (MoS2 and TiO2), and four test specimens with B/L ratios ranging from 0.5 to 2.0 were used. An alternative experimental method has been used to simulate wear debris in the dry contact tribosystems, vis-à-vis dry powders, which were introduced into the interface gap to address the affinity of the wear process. Slider pads' performance characteristics as a function of the applied load (ranging from 34.5 to 345 kPa) and surface speed (0.004 to 4.5 m/sec) were determined at ambient condition. Experimental evidence shows that in the pre-hydrodynamic regime (low speed) the friction coefficient, η, decreases as B/L ratio increased from 0.5 to 1.5. Beyond a B/L ratio of 1.5, η increased with increasing B/L ratios. Optimum B/L ratio of 1 (based on measured minimum η) was identified for operation in the hydrodynamic regime. Overall reduction in η as a function of load was observed which is independent of B/L ratio and lubricant type. Also presented are the velocity effects on slider frictional performance. 相似文献
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The behavior of a fluid-film bearing depends on the boundary conditions at the interfaces between the liquid and the solid bearing surfaces. For almost all solid surfaces, the no-slip boundary condition applies. However, a number of researchers have recently found that slip can occur with specially engineered surfaces. These include molecularly smooth surfaces and surfaces with micron-scale patterns. By constructing an engineered heterogeneous surface on which slip occurs in certain regions and is absent in others, the flow in the liquid film of a bearing can be altered, and such characteristics as load support and friction can be improved. In the present study, a numerical analysis of a slider bearing with such an engineered slip/no-slip surface is analyzed. Slip is assumed to occur when a critical shear stress is exceeded and follows the Navier relation. The results show that with a critical shear stress of zero, a significant increase in load support and decrease in friction can be achieved with an appropriate surface pattern. With nonzero values of critical shear stress, an instability occurs over a range of speeds. At speeds above this range, the bearing behaves similar to the case with zero critical shear stress, while below this range it behaves like a conventional bearing. 相似文献
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