Journal articles: 'Air bearing surface'

1

Pitarresi, J. M., and K. A. Haller. "An Air Layer Modeling Approach for Air and Air/Vacuum Bearings." Journal of Manufacturing Science and Engineering 119, no. 3 (August 1, 1997): 388–92. http://dx.doi.org/10.1115/1.2831118.

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Air layer supported bearing pads, or “air bearings” as they are commonly called, are popular because of their high load capacity and low in-plane coefficient of friction, making them well suited for supporting moving, high accuracy manufacturing stages. Air/vacuum bearings enhance these capabilities by giving the bearing pad load resistance capacity in both the upward and downward directions. Consequently, it is desirable to know how to model the air layer between the bearing pad and the bearing surface. In this paper, a simple finite element modeling approach is presented for investigating the vibrational characteristics of an air layer supported bearing. It was found that by modeling the air layer as a bed of uniform springs who’s stiffness is determined by load-displacement tests of the bearing, a reasonable representation of the response can be obtained. For a bearing supported by air without vacuum, the dynamic response was very similar to that of a freely supported bearing. The addition of vacuum to an air bearing was found to significantly lower its fundamental frequency which could lead to unwanted resonance problems.

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2

Lee, Jongsoo, and Jiwon Kim. "Design Optimization of the Air Bearing Surface for the Optical Flying Bead." Transactions of the Korean Society of Mechanical Engineers A 29, no. 2 (February 1, 2005): 303–10. http://dx.doi.org/10.3795/ksme-a.2005.29.2.303.

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3

He, D. X., B. H. Sheng, Zu De Zhou, Q. Suo, Y. F. Li, and C. Y. Liu. "Improvement of Diamond-Cutting Surface by Means of Porous Bearing Laminar Flow." Advanced Materials Research 69-70 (May 2009): 88–92. http://dx.doi.org/10.4028/www.scientific.net/amr.69-70.88.

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Air bearings had been widely used in ultra-precision machine tools. In order to suppress the micro-vibration caused by air bearing, an effective way is keeping the air flow in laminar state. Porous bearing to control the micro-vibration was proposed in this paper, and the related experiments show that it can meet the requirement of decreasing the micro-vibration to less than 1nm, and the surface of diamond surface can be improved.

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4

Li, He, Yuxiang Hua, Qiquan Quan, Deen Bai, Yinchao Wang, and Zongquan Deng. "On the modeling of levitation force for ultrasonic journal bearings actuated by piezoelectric transducers." Journal of Intelligent Material Systems and Structures 29, no. 6 (September 20, 2017): 1113–19. http://dx.doi.org/10.1177/1045389x17730918.

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Different from conventional hydrostatic or hydrodynamic journal bearings, an ultrasonic journal bearing provides carrying force by air squeeze film generated by high-frequency vibration of bearing bush surfaces. Detailed investigation indicates that studies on levitating force modeling based on fluid dynamics for ultrasonic journal bearings are rarely conducted, and the existing theoretical models generally neglect some significant contributors to levitating force such as gas inertia, surface topography, rarefaction effect, or boundary effect. A modified Reynolds-type equation considering these factors is put forward in this study to predict the ultrasonic journal bearing’s carrying capacity. The numerical solving results can interpret the experimental data well. The proposed model will provide theoretical reference for the design of ultrasonic journal bearings.

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Zhou, Quan, Yu Hou, and Ru Gang Chen. "Application of Materials on Foil Thrust Bearings for Micro Turbines." Advanced Materials Research 201-203 (February 2011): 2759–62. http://dx.doi.org/10.4028/www.scientific.net/amr.201-203.2759.

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Foil bearing that has a soft surface is a kind of air bearing. The performances of foil bearings are greatly affected by the materials of bearing surface, which is called foil element. In order to estimate the performance of foil bearings, two kinds of foil thrust bearings that are made of different materials respectively were tested in a micro turbine system, which contains rotation part and static part. Load capacity and stability of these foil thrust bearings were investigated in experiments. The results show that bearing which contains rubber has higher load capacity and bearing which contains copper foil has higher stability. According to the work in this paper, applications with different requirements can adopt suitable foil thrust bearing.

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Xu, Fangcheng, Yi Sun, Guanghui Zhang, and Zhansheng Liu. "Effect of bump structural friction on the performance of bump foil bearing and rotor dynamic behavior: Experimental study." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 233, no. 5 (August 15, 2018): 702–11. http://dx.doi.org/10.1177/1350650118794536.

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Air foil bearings are a kind of self-acting lubricated bearing, which have potential applications in high-speed turbomachinery. Air foil journal bearings have simple structure that consists of top foil, bump foil, and bearing sleeve, and use gas as working fluid. However, the relative motion of top foil and bump foil, bump foil and bearing sleeve occurs when dynamic pressure is generated as long as there is spinning of shaft. Thus, the friction between each part of bearing should be considered when modeling. Many papers have theoretically shown the effect of Coulomb friction between top foil and top foil, bump foil and bearing sleeve on the static and dynamic performances of air foil journal bearing by developing many bump foil structural models. The results show that this foil structural Coulomb friction can significantly make bump foil stiffer. However, the improvement of the Coulomb friction effect through experiments is quite difficult and there is no study regarding this so far. The purpose of this paper is to certify the Coulomb effect on bearing performance by using experimental method. Two bump foil journal bearings are manufactured with different bearing sleeve surface roughnesses. Foil structure stiffness, bearing lift-off speed, and rotor dynamic behavior supported by two sets of bearings are measured and compared.

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Gogól, Jacek, and Janusz Franczak. "Thermal analysis of air gap between air bearing working surface and working guide surface." Mechanik, no. 5-6 (May 2016): 558–59. http://dx.doi.org/10.17814/mechanik.2016.5-6.85.

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8

Hu, Yong. "Ramp-Load Dynamics of Proximity Recording Air Bearing Sliders in Magnetic Hard Disk Drive." Journal of Tribology 121, no. 3 (July 1, 1999): 560–67. http://dx.doi.org/10.1115/1.2834104.

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The revival of dynamic load/unload (L/UL) technology forces us to rethink the air bearing design philosophy, which has traditionally been established for contact start/stop applications. Reliably loading a slider onto a full-rotating disk imposes its own requirements on the slider air bearing designs. This paper addresses the unique design requirements of dynamic L/UL technology, through an investigation of the air bearing characteristics of two proximity recording sliders during a dynamic load process. While the slider/disk contact force is employed as a key indicator of the reliability of the dynamic load mechanism, the air bearing suction force and squeeze flow effect are used to characterize the slider’s dynamics during loading. The effects of the slider’s loading velocity, pitch and roll static attitudes on its dynamic load performance are simulated. In comparison to the positive pressure air bearings, both the enlarged air bearing surface and shallowly recessed cavities of the subambient pressure air bearing sliders generate more squeeze flow, resulting in a rapid development of the air bearing lifting force at a higher attitude. This often leads to a more reliable dynamic load performance. The impact of the air bearing suction force on the slider’s dynamics during loading is determined by the suction force center. A towards-leading-edge suction force not only induces a negative pitch motion during the early stage, but also prolongs the pitch-up process. Both effects can result in a head crash for the slider with a large negative pitch static attitude. In summary, the subambient pressure air bearing sliders that feature the enlarged leading air bearing surface and towards-trailing-edge suction cavities with small recess depth offer a fast pitch-up load performance.

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9

Shuyu Zhang, G. Tyndall, and M. Suk. "Air Bearing Surface Designs for Less Humidity Sensitivity." IEEE Transactions on Magnetics 44, no. 11 (November 2008): 3653–55. http://dx.doi.org/10.1109/tmag.2008.2004210.

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10

Shen, Xinjiang, and David B. Bogy. "Particle Flow and Contamination in Slider Air Bearings for Hard Disk Drives." Journal of Tribology 125, no. 2 (March 19, 2003): 358–63. http://dx.doi.org/10.1115/1.1537746.

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For a particle entrained in an air bearing, various forces, such as the viscous drag force, Saffmann and Magnus lift forces and gravity force, will act on it. Such particles may pass through the air bearing or impact the slider or disk and then adhere to the surface or bounce off. In this paper, particle flow in an air bearing is simulated. The contamination of particles on a slider’s surface is analyzed using the assumption of adhesion upon impact. The effect of particle size and density on particle paths in the air bearing is studied. The numerical results show that particles are likely to contaminate slider surfaces in the transition regions on the rails. The density of the particles and the pitch angle of the slider are also found to strongly affect the flying path of the particles, and therefore, the accumulation of the particles on slider surfaces.

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11

Kodnyanko, Vladimir, Stanislav Shatokhin, Andrey Kurzakov, Yuri Pikalov, Iakov Pikalov, Olga Grigorieva, Lilia Strok, and Maxim Brungardt. "Numerical Modeling on the Compliance and Load Capacity of a Two-Row Aerostatic Journal Bearing with Longitudinal Microgrooves in the Inter-Row Zone." Applied Sciences 11, no. 12 (June 20, 2021): 5714. http://dx.doi.org/10.3390/app11125714.

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Aerostatic bearings are attractive, with minimal friction losses, high durability, and environmental friendliness. However, such designs have a number of disadvantages, including low load-bearing capacity and high compliance due to high air compressibility and limited injection pressure. The article proposes a double-row aerostatic journal bearing with an external combined throttling system and longitudinal microgrooves in the inter-row zone. It is hypothesized that the use of microgrooves will reduce the circumferential flows of compressed air, as a result of which the compliance should decrease and the bearing capacity should increase. To test the hypothesis, we carried out the mathematical modeling, calculations, and theoretical study of stationary operation modes of the bearing for small shaft eccentricities in the vicinity of the central equilibrium position of the shaft and bearing capacity for arbitrary eccentricities. Formulas were obtained for the numerical evaluation of compliance for bearings with a smooth bushing surface and with longitudinal microgrooves. Iterative finite-difference methods for evaluating the fields of the squared pressure are proposed, on the basis of which the load capacity of the bearings is calculated. Experimental verification of the bearing’s theoretical characteristics was carried out, which showed satisfactory agreement between the compared data. The study of the compliance and load capacity of a microgroove bearing yielded impressive results. We show that the positive effect from the application of the improvement begins to manifest itself already at four microgrooves; the effect becomes significant at six microgrooves, and at twelve or more microgrooves, the circumferential flows in the bearing gap practically disappear; therefore, the bearing characteristics can be calculated on the basis of one-dimensional models of air lubrication longitudinal flow. Calculations have shown that for a length of L = 1, the maximum load capacity of a bearing with microgrooves is 1.5 times higher than that of a conventional bearing; for L ≥ 1.5, the bearing capacity increases twice or more. The result obtained allows us to recommend the proposed improvement for practical use in order to increase the load capacity of aerostatic journal bearings significantly.

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12

DellaCorte, Christopher, Antonio R. Zaldana, and Kevin C. Radil. "A Systems Approach to the Solid Lubrication of Foil Air Bearings for Oil-Free Turbomachinery." Journal of Tribology 126, no. 1 (January 1, 2004): 200–207. http://dx.doi.org/10.1115/1.1609485.

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Foil air bearings are self-acting hydrodynamic bearings which rely upon solid lubricants to reduce friction and minimize wear during sliding which occurs at start-up and shut-down when surface speeds are too low to allow the formation of a hydrodynamic air film. This solid lubrication is typically accomplished by coating the nonmoving foil surface with a thin, soft polymeric film. The following paper introduces a systems approach in which the solid lubrication is provided by a combination of self lubricating shaft coatings coupled with various wear resistant and lubricating foil coatings. The use of multiple materials, each providing different functions is modeled after oil-lubricated hydrodynamic sleeve bearing technology which utilizes various coatings and surface treatments in conjunction with oil lubricants to achieve optimum performance. In this study, room temperature load capacity tests are performed on journal foil air bearings operating at 14,000 rpm. Different shaft and foil coating technologies such as plasma sprayed composites, ceramic, polymer and inorganic lubricant coatings are evaluated as foil bearing lubricants. The results indicate that bearing performance is improved through the individual use of the lubricants and treatments tested. Further, combining several solid lubricants together yielded synergistically better results than any material alone.

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13

Wang, Chuang, Ziwen Xing, Xi Pan, and Zhilong He. "Simulation of the characteristics of the water-lubricated journal bearing in twin-screw air compressor." Industrial Lubrication and Tribology 70, no. 8 (November 12, 2018): 1476–86. http://dx.doi.org/10.1108/ilt-05-2017-0134.

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Purpose The well-operating condition of journal bearing is the assurance to keep superior performance of water-lubricated twin-screw compressor. To design the journal bearing more reasonably for this type of compressor, this paper aims to study the effects of rotating speed and design parameters on bearing characteristics, considering surface roughness and bending deformation of the shaft at the same time. Design/methodology/approach The average Reynolds equation considering the effect of surface roughness is adopted and solved by finite difference method and successive over-relaxation method to calculate pressure distribution with real bearing shapes and boundary conditions. The bending deformation of the shaft is calculated using simply supported beam model of variable cross-section. Findings The dynamic lubrication characteristics of four water-lubricated journal bearings in twin-screw air compressor are calculated and analyzed. In addition, the static characteristics of journal bearing including friction coefficient, film thickness ratio distribution and water film pressure distribution are calculated numerically with different rotating speed and design parameters. Moreover, some design principles of water-lubricated bearing for twin-screw compressor are put forward. Originality/value The lubrication characteristics of the water-lubricated journal bearing in twin-screw air compressor are calculated considering surface roughness and bending deformation of the shaft at the same time. The paper’s results may provide design guidelines for journal bearing in this kind of twin-screw compressor.

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14

Hingawe, Nilesh D., and Skylab P. Bhore. "Tribological performance of a surface textured meso scale air bearing." Industrial Lubrication and Tribology 72, no. 5 (October 26, 2019): 599–609. http://dx.doi.org/10.1108/ilt-04-2019-0146.

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Purpose The purpose of this study is to improve the tribological performance of meso scale air journal bearing by adopting texture on the bearing surface. Design/methodology/approach The present study is based on numerical analysis. The detailed numerical investigation is carried out using a fluid flow based thin-film model in COMSOL 5.2 software. Findings The influence of texture design parameters: geometry (shape, orientation and slender ratio), and position on the tribological performance of meso scale air journal bearing is investigated. It is found that texture shape has a strong influence on the tribological characteristics such as load capacity and friction coefficient of the bearing. Slender texture improves the load capacity, but it has a negligible effect on the reduction of friction coefficient. In contrast, texture orientation is found to be insignificant for both increasing load capacity and decreasing friction coefficient. Furthermore, the maximum improvement in load capacity is obtained for partially textured bearing, but the minimum friction coefficient is achieved for full texturing. Originality/value The present study investigates the influence of texture design parameters viz geometry (shape, orientation and slender ratio), and position on the tribological performance of meso scale air journal bearing.

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15

Shen, Xinjiang, Mike Suk, and David B. Bogy. "Study of Transverse Flow Effects on Particle Flows and Contamination of Air Bearing Sliders." Journal of Tribology 126, no. 4 (October 1, 2004): 745–50. http://dx.doi.org/10.1115/1.1757489.

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For some complex slider designs the two dimensional approximation incorporated in the Reynolds equation for determining the airflow in the air bearing is not applicable due to steps in the air bearing surface. A model that incorporates some transverse flow effects is needed to better characterize the airflow between the slider and disk for some applications. In this paper such a model is derived to better predict the paths of contamination particles entrained in the air bearing. The characteristics of airflow and particle flow within the air bearing are then studied. The analysis including the transverse effects reveals that the transverse velocity of the air is not negligible in the geometric transition regions of the slider. This transverse velocity has a significant effect on the flight path of particles, and therefore, on the particle contamination profile on slider surfaces. The assumption of adhesion of the particles upon impact with a surface is used as the contamination criteria, and it is viewed as the worst-case scenario.

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16

Yoon, Sang-Joon, and Dong-Hoon Choi. "Probabilistic Designs of Air-Bearing Surface on Manufacturing Tolerances." Journal of Tribology 127, no. 1 (January 1, 2005): 149–54. http://dx.doi.org/10.1115/1.1828453.

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The focus in this paper is to automatically design the air-bearing surface (ABS) considering the randomness of its geometry as an uncertainty of design variables. Designs determined by the conventional optimization could only provide a low level of confidence in practical products due to the existence of uncertainties in either engineering simulations or manufacturing processes. This calls for a reliability-based approach to the design optimization, which increases product or process quality by addressing randomness or stochastic properties of design problems. In this study, a probabilistic design problem is formulated considering the reliability analysis which is employed to estimate how the fabrication tolerances of individual slider parameters affect the final flying attitude tolerances. The proposed approach first solves the deterministic optimization problem. Beginning with this solution, the reliability-based design optimization (RBDO) is continued with the probabilistic constraints affected by the random variables. Probabilistic constraints overriding the constraints of the deterministic optimization attempt to drive the design to a reliability solution with a minimum increase in the objective. The simulation results of the probabilistic design are directly compared with the values of the initial design and the results of the deterministic optimum design, respectively. In order to show the effectiveness of the proposed approach, the reliability analyses by the Monte Carlo simulation are carried out. And the results demonstrate how efficient the proposed approach is, considering the enormous computation time of the reliability analysis.

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17

Sy Truong, Dinh, Byung-Sub Kim, and Jong-Kweon Park. "Thermally affected stiffness matrix of angular contact ball bearings in a high-speed spindle system." Advances in Mechanical Engineering 11, no. 11 (November 2019): 168781401988975. http://dx.doi.org/10.1177/1687814019889753.

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Bearing stiffness directly affects the dynamic characteristics in a high-speed spindle system and plays an important role in terms of manufacturing quality. We developed a new approach for predicting the thermal behavior of a high-speed spindle, calculated the thermal expansion, and generated a bearing stiffness matrix for angular contact ball bearings. The heat convection of spindle housing in air, the balls in lubricant, the spindle shaft in quiescent air, and the bearing inner ring surfaces were determined. Heat sources such as bearing friction, and the heat contributed by the built-in motor, were simulated using an analysis systems (ANSYS) steady-state thermal model. The results were imported into a static ANSYS structural model. Ball thermal expansion was calculated based on changes in the coordinates of nodal points on the ball surface. Finally, a thermally affected bearing stiffness matrix was generated by applying the Newton–Raphson technique. Decreases in the bearing radial, axial, angular, and coupling stiffness values as rotational spindle speed increased were calculated. Also, the stiffness coefficients at a specific speed increased significantly caused by the thermal effects. Finally, for validation, the bearing stiffness was compared to that calculated using an earlier thermal network approach.

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18

Zhu, Hong, and David B. Bogy. "Hard disc drive air bearing design: modified DIRECT algorithm and its application to slider air bearing surface optimization." Tribology International 37, no. 2 (February 2004): 193–201. http://dx.doi.org/10.1016/s0301-679x(03)00036-7.

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19

Iida, Kohei, and Kyosuke Ono. "Analysis of Bouncing Vibrations of a 2-DOF Model of Tripad Contact Slider Over a Random Wavy Disk Surface." Journal of Tribology 123, no. 1 (September 19, 2000): 159–67. http://dx.doi.org/10.1115/1.1330743.

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We numerically analyzed the bouncing vibrations of a two-degree-of-freedom (2-DOF) model of a tri-pad contact slider with air bearing pads over a random wavy surface and manifested the design conditions of a contact slider. The effects of the design parameters such as air bearing stiffness, contact damping ratio, the coefficient of friction, and the characteristics of the disk surface waviness on dynamic behavior and the contact sliding ability of the slider have been investigated. As a result, we found that friction force decreases the contact sliding ability at the boundary of the intermittent and continuous contact sliding. We also found that the distance between the rear air bearing center and the contact pad has a significant effect on the contact sliding ability. If the contact pad is apart from the rear air bearing center, the contact pad tends to separate from the disk. Based on this analytical study, we have proposed two design concepts: (1) Make the distance between the rear air bearing center and the contact pad as small as possible; in this case, the larger the rear air bearing stiffness results are, the better the contact ability is; (2) If some distance between the rear air bearing center and the contact pad is inevitable, then make the rear air bearing stiffness much smaller than the contact stiffness.

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20

Peng, Z.-C., and M. M. Khonsari. "A Thermohydrodynamic Analysis of Foil Journal Bearings." Journal of Tribology 128, no. 3 (February 16, 2006): 534–41. http://dx.doi.org/10.1115/1.2197526.

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A thermohydrodynamic model is developed for predicting the three-dimensional (3D) temperature field in an air-lubricated, compliant foil journal bearing. The model accounts for the compressibility and the viscosity-temperature characteristic of air and the compliance of the bearing surface. The results of numerical solutions are compared to published experimental measurements and reasonable agreement has been attained. Parametric studies covering a fairly wide range of operating speeds and load conditions were carried out to illustrate the usefulness of the model in terms of predicting the thermal performance of foil journal bearings.

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21

Shen, Ching. "An Alternative Simulation Method for Calculation of Microgas Flows under Flying Head Sliders." Advances in Tribology 2009 (2009): 1–10. http://dx.doi.org/10.1155/2009/461793.

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The precise knowledge of the force and moment generated by the air squeezed under the read-write slider by the rotating disc is an engineering necessity in designing the air bearing surface slider. This paper reviews methods addressing the thin gas film bearings problem. It firstly reviews briefly the relatively well-known two methods of calculations of the microgas flows under flying head sliders, the generalized Reynolds equation, having given a number of useful results of slider design, and the DSMC method, which is precise and appropriate for the flow of complex configurations but is restricted to miniature (~micrometer) size sliders. The main purpose of the paper is to introduce to the reader an alternative method, the information preservation (IP) method, for use in simulation of the flows under air bearing surfaces. Some recent results of IP simulation of slider flows published on conference proceedings are introduced here.

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22

Myo, Kyaw Sett, Weidong Zhou, Xiaoyang Huang, Shengkai Yu, and Wei Hua. "Slider Posture Effects on Air Bearing in a Heat-Assisted Magnetic Recording System." Advances in Tribology 2012 (2012): 1–6. http://dx.doi.org/10.1155/2012/169207.

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This paper reports the effects of slider posture on the slider bearing in a heat-assisted magnetic recording (HAMR) system with the direct simulation Monte Carlo (DSMC) method. In this HAMR system, the heat issues on the slider bearings are assumed to be caused by a heated spot on the disk and/or slider body itself at various pitch angles. The simulation results show that with a heated spot on the disk, the air bearing pressure and air bearing force that acted on the slider surface will increase when the pitch angle becomes larger. It is also found that the bearing force increases with the heated spot size and the effects of a heated spot become more obvious at a larger pitch angle. On the other hand, the slider body temperature is observed to have a noticeable effect on air bearing pressure and force. The smaller pitch angle enlarges the tendency of bearing force variations with the slider temperature and makes the slider more sensitive to its temperature changes.

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23

Trinh, Quang Hung. "NUMERICAL AND EXPERIMENTAL STUDY OF AEROSTATIC BEARINGS WITH VIRTUAL RECESSES AND MULTI-HOLE ORIFICES." Journal of Science and Technique 15, no. 3 (July 1, 2020): 48–57. http://dx.doi.org/10.56651/lqdtu.jst.v15.n03.117.

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Aerostatic bearings are ones which carry loads with nearly frictionless movement, thanks to external supply of pressurized air. The bearing pad and guide surfaces are kept apart and lubricated by a micrometer-thick compressed air film with a load capacity depending mainly on the pressure distribution. The flow of air through the gap complies with the Navier-Stokes equations and conservation of mass and energy. As Navier-Stokes equations are nonlinear differential equations, solving the aerostatic-bearing problem by numerical simulation using finite volume method in combination with experiments is considered to be effective and reliable. In this report, the influences of a virtual recess and multi-hole orifice on the performance of a rectangular flat aerostatic bearing were numerically analyzed using Ansys CFX solver. The results show that the presence of a virtual recess and its dimensions largely influence the bearing performance in terms of pressure distribution and load capacity. Similarly, the multi-hole orifice also has a significant effect on the enhancement of the performance of the bearing. The area of positive gauge pressure has been shown to be extended to almost entire bearing surface in both cases, which considerably improve the load capacity and stability. The effect of gas gap studied on the multi-hole orifice bearing indicates that the load capacity decreases with increasing the gas gap, being found to be in a fairly good agreement with the experiment.

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Chiba, H., T. Musashi, Y. Kasamatsu, J. Watanabe, T. Watanabe, and K. Watanabe. "Chemically modified air-bearing surface for the near-contact regime." IEEE Transactions on Magnetics 41, no. 10 (October 2005): 3049–51. http://dx.doi.org/10.1109/tmag.2005.855259.

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Zhang, Mingsheng, Yijun Man, and Bo Liu. "High Selectivity Etching for Texture Fabrication on Air Bearing Surface." IEEE Transactions on Magnetics 43, no. 6 (June 2007): 2238–40. http://dx.doi.org/10.1109/tmag.2007.893420.

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Wang, Geng, Yufeng Li, and Hyung J. Lee. "The effect of air-bearing surface roughness on avalanche test." Journal of Applied Physics 87, no. 9 (May 2000): 6176–78. http://dx.doi.org/10.1063/1.372647.

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Liu, Sen, Hui Li, Shengnan Shen, and Shijing Wu. "Simulation of particle rebounding from the slider air bearing surface." Microsystem Technologies 22, no. 6 (February 2, 2016): 1475–81. http://dx.doi.org/10.1007/s00542-016-2847-x.

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Zhang, Mingsheng, Shengkai Yu, Jin Liu, and Bo Liu. "Flying height adjustment by slider’s air bearing surface profile control." Journal of Applied Physics 97, no. 10 (May 15, 2005): 10P309. http://dx.doi.org/10.1063/1.1853671.

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Murthy, Aravind N., Izhak Etsion, and Frank E. Talke. "Analysis of Surface Textured Air Bearing Sliders with Rarefaction Effects." Tribology Letters 28, no. 3 (September 28, 2007): 251–61. http://dx.doi.org/10.1007/s11249-007-9269-y.

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Zdziebko, Paweł, and Adam Martowicz. "Study on the temperature and strain fields in gas foil bearings – measurement method and numerical simulations." Eksploatacja i Niezawodnosc - Maintenance and Reliability 23, no. 3 (July 5, 2021): 540–47. http://dx.doi.org/10.17531/ein.2021.3.15.

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Gas foil bearings belong to the group of slide bearings and are used in devices in which operation at high rotational speeds of the shafts are of key importance, e.g., in gas turbines. The air film developed on the surface of the bearing’s top foil allows this structural component to be separated from the shaft. This ensures a non-contact operation of the bearing. In the case of the mentioned type of bearings, their resultant operational properties are influenced by both thermal and mechanical phenomena. The current work presents a model of a gas foil bearing developed making use of the Finite Element Method. The model takes into account thermomechanical couplings which are necessary for the correct simulation of the operation of physical components of the modeled system. The paper reports the results of numerical analyzes conducted for the elaborated model as well as the relevant conclusions concerning thermomechanical couplings present in gas foil bearings. The method for the experimental identification of the temperature and strain fields in the bearing’s top foil proposed to validate the numerical model is also presented.

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Wenski, T. E., T. Olson, C. T. Rettner, and Alejandro L. Garcia. "Simulations of Air Slider Bearings With Realistic Gas-Surface Scattering." Journal of Tribology 120, no. 3 (July 1, 1998): 639–41. http://dx.doi.org/10.1115/1.2834599.

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We have calculated the pressure distribution for an infinitely wide plane slider air bearing by using a particle-based direct simulation Monte Carlo method. These simulations include a sophisticated gas-surface scattering model and take measured accommodation coefficients as inputs. Our results are in good agreement with the molecular gas lubrication theory of Fukui and Kaneko for both glass and disk-drive surfaces.

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32

Ito, So, Kang Won Lee, Yuki Shimizu, and Wei Gao. "Improvement of an Air-Bearing Displacement Sensor with Nanometric Resolution." Key Engineering Materials 523-524 (November 2012): 945–50. http://dx.doi.org/10.4028/www.scientific.net/kem.523-524.945.

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A contact stylus-type displacement sensor is proposed for a surface form measurement of micro-structures. The stylus is supported by an air-bearing, thus it can be moved smoothly without friction between the stylus and the air-bearing. In order to reduce the measurement force, a novel controlling technique of a contact force has been developed. During the measurement one edge of the stylus is maintained contact with the measured surface by its own weight. Another end of the stylus is connected with a counter weight by a string and the stylus is hanging on the string in order to reduce the contact force between the edge of the stylus and the measured surface. Measuring force is estimated to confirm the effectiveness of the counter weight. Surface measurement of a steel ball is carried out using the developed air-bearing displacement sensor.

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Lu, Chung-Jen, and Tai-Kuo Wang. "New Designs of HDD Air-Lubricated Sliders Via Topology Optimization." Journal of Tribology 126, no. 1 (January 1, 2004): 171–76. http://dx.doi.org/10.1115/1.1631016.

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Optimization is an efficient tool for developing designs of slider air bearings that meet the strict performance demands of current hard disk drives. Previous studies in this field concentrated on determining the optimal size and shape of the air-bearing surface for a specified initial design. The resulting optimal design has the same topology as that of the initial design. Therefore, the performance of the final optimal solution depends strongly on the initial design, which is chosen either intuitively or inspired by already existing designs. In this study, a topology optimization method is developed for determining the optimal slider configuration. First, the air-bearing surface is discretized by a uniform mesh. The optimization consists in determining whether the material contained in each element should be removed or not. Then, a genetic algorithm is employed for the determination of the optimal solution from the possible candidates. An example is presented to demonstrate the effectiveness of the proposed approach. The resulting optimal design has a topology different from those of the initial designs and possesses improved performance.

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White, J. W. "Flying Characteristics of the Transverse and Negative Pressure Contour (“TNP”) Slider Air Bearing." Journal of Tribology 119, no. 2 (April 1, 1997): 241–48. http://dx.doi.org/10.1115/1.2833166.

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The TNP contour air bearing slider is composed of oversized transverse pressure contour (TPC) outer rails and a central negative pressure (NP) cavity. The NP cavity is separated from the TPC rails by an ambient pressure reservoir which serves two functions. First, it prevents direct hydrodynamic interaction between the various component air bearing surfaces and thus, eliminates pressure distortion and dilution, common causes of problems related to flying height and roll angle control. Second, the ambient reservoir allows the TPC rails and NP cavity to be configured and dimensioned independently so that they will track each other with a nearly constant force difference, resulting in a flying height that has significantly reduced sensitivity to altitude change. The multi-function TPC sections of the outside rails are able to overcome the effects of a changing radius and wide skew angle variation over the disk radius as well as a changing vacuum load and asymmetry of the NP cavity pressure, in order to provide a truly constant low flying height over the entire data surface. The combination of a high air bearing stiffness and a gradually developing cavity vacuum as disk velocity increases produces a rapid slider take-off from the disk surface. Dynamic stability of the TNP slider air bearing is enhanced by the unusual combination of a high air bearing stiffness and high air film damping in each of the three slider excursion modes. Finally, the TNP slider experiences a reduced sensitivity of flying height to manufacturing and operational tolerances as compared to non-NP type sliders. The entire TNP slider air bearing is created by a two-etch process. A shallow etch creates the TPC sections and leading edge step. A deeper etch forms the NP cavity, ambient pressure reservoir, and outermost edge of each side rail.

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Yoshimoto, S., and K. Kohno. "Static and Dynamic Characteristics of Aerostatic Circular Porous Thrust Bearings (Effect of the Shape of the Air Supply Area)." Journal of Tribology 123, no. 3 (June 30, 2000): 501–8. http://dx.doi.org/10.1115/1.1308027.

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Recently, graphite porous material has been used successfully in an aerostatic bearing. In actual bearing design, it is often necessary to reduce the thickness of porous material to make the bearing smaller. However, a reduction in thickness results in a reduction in the strength of the porous material. In particular, when the diameter of porous material is large, it is difficult to supply the air through the full pad area of porous material because it deforms. Therefore, in this paper, two types of air supply method (the annular groove supply and the hole supply) in a circular aerostatic porous thrust bearing are proposed to avoid the deflection of the bearing surface. The static and dynamic characteristics of aerostatic porous bearing with these air supply methods are investigated theoretically and experimentally. In addition, the effects of a surface restricted layer on the characteristics are clarified.

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Kang, Tae-Sik, Dong-Hoon Choi, and Tae-Gun Jeong. "Optimal Design of HDD Air-Lubricated Slider Bearings for Improving Dynamic Characteristics and Operating Performance." Journal of Tribology 123, no. 3 (July 6, 2000): 541–47. http://dx.doi.org/10.1115/1.1308031.

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Flying attitudes of the slider, which are flying height, pitch, and roll, are affected by air-flow velocity, skew angle, and manufacturing tolerances. In the traditional design process of air-bearing surfaces, we have considered only the steady state flying attitude over the recording band. To reduce the flying height variation during track seek as well as in steady state, we design a new shape for air-bearing surfaces. An optimization technique is used to improve the dynamic characteristics and operating performance of the new air-bearing surface shapes. The quasistatic approach is used in the numerical simulation of the track seek operation because the skew angle effect dominates the inertial effect even at high seek velocities. The perturbation method is applied to the lubrication equation to obtain the air-bearing stiffness. We employ the method of modified feasible directions and use the weighting method to solve the multicriteria optimization problem. The optimally designed sliders show enhanced flying and dynamic characteristics. The steady state flying heights are closer to the target values and the flying height variations during track seek operation are smaller than those for the original ones. The pitch and roll angles are kept within suitable ranges over the recording band during track seek operation as well as in steady state. The air-bearing stiffnesses of the optimally designed sliders are larger than those of the original ones.

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Sun, Qi Guo, Yue Fei Wang, Ying Wang, and Hong Bo Lv. "Comparing of Temperatures of Rolling Bearing under the Oil-Air Lubrication to the Spray Lubrication." Applied Mechanics and Materials 395-396 (September 2013): 763–68. http://dx.doi.org/10.4028/www.scientific.net/amm.395-396.763.

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The heat generating mechanism inside the cavity of rolling bearing is analyzed and the convective heat transfer coefficient of bearing raceway surface in different rotational speed is calculated under the oil-air lubrication and the spray lubrication in this paper. The fluid domain geometry model of deep groove ball bearing SKF6208 is established, employing the flow field module in Workbench. The comparing simulations of the temperatures of rolling bearing cavity under the oil-air lubrication to the spray lubrication are done in different rotational speed. The simulation results show that the highest temperature of bearing cavity with the oil-air lubrication is almost the same to the spray lubrication when the bearing rotational speed is lower, and the highest temperature of bearing cavity with the oil-air lubrication is far lower than the spray lubrication when the bearing rotational speed is higher. Those conclusions verify the advantages of the oil-air lubrication in high rotational speed.

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Xu, Wanjun, and Jiangang Yang. "The Air Lubrication Behavior of a Kingsbury Thrust Bearing Demonstration." International Journal of Rotating Machinery 2021 (February 27, 2021): 1–10. http://dx.doi.org/10.1155/2021/6690479.

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In order to understand the air lubrication behavior of Kingsbury thrust bearing demonstration, an experimental and theoretical investigation on a simulated Kingsbury thrust bearing was presented. The motions of the thrust disk and tilting pads were measured by eddy current sensors for three mass load cases. A simplified theoretical model governing the motion of the thrust disk was established. The bearing successfully passed the examination of lamp extinction and maintained the maximum rotation time of 16 s. The effective hydrodynamic film with a thickness of about 5 μm was concentrated on the middle region of the working surface under a flatness of 0.010 mm. The adverse effect of the three surface bumps was minimized by the swing motion of tilting pads. Moreover, about 1/3 air film thickness was shown to be wasted due to the surface irregularity. However, the requirements of surface quality and misalignment were appropriately relaxed through the design of the centrally pivoted tilting pads. This design is conducive to thin-film lubrication and is a potential application for microturbines.

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Hu, Hongyang, and Ming Feng. "Performance of novel air foil thrust bearings with taper-groove on surface of top foil." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 235, no. 1 (May 13, 2020): 79–92. http://dx.doi.org/10.1177/1350650120925338.

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To improve the load capacity of air foil thrust bearing, the micro taper-grooves on the surface of top foil was introduced and studied. A modified Reynolds equation considering the gas rarefaction effect was established, in which the Knudsen number was affected by the film thickness and pressure. A new bump stiffness model was built with the consideration of bump rounding, friction, and bending stiffness of foil. By considering the variation of gas film thickness, the load capacity, friction torque, and power loss of novel bearing with grooves were calculated by the finite difference method. Moreover, the effect law of groove parameters, groove shape and grooves number on the novel bearing performance was studied systematically. The results show that the predicted axial load capacity considering gas rarefaction effect is decreased slightly in smaller clearance and more consistent with the actual test data. The novel air foil thrust bearing with taper-groove can weaken the air end leakage and enhance the local dynamic pressure efficiently in the parallel portion of top foil, thus improving the static characteristics of bearing. For the novel air foil thrust bearing with taper-groove depth of 10 µm, the load capacity can be increased by about 13.33%, compared with traditional bearing. With the increments of taper-groove depth and length on top foil, the load capacity can be increased. However, the friction torque is decreased when there is a longer taper-groove in the circumferential direction. Meanwhile, the optimal groove width ratio is about 0.5, and the structure of multi-grooves is beneficial to the decreased friction torque. The validity of presented theoretical model has been verified by the literature data, and the results are expected to be helpful to bearing designers, researchers, and academicians concerned.

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Liang, Jie, Xiao Fang Xie, Jian Cao, and Xun Qiang Hu. "The Visual Simulation of Air-to-Surface Missile Bearing-Only Attack." Advanced Materials Research 457-458 (January 2012): 872–76. http://dx.doi.org/10.4028/www.scientific.net/amr.457-458.872.

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In order to evaluate the air-to-surface missile bearing-only attack effect u, the paper introduces a method which is based on EspCreator platform to develop the virtual reality simulation system. The 3D geometric models of the sea view、fighter plane、 air-to-surface missile and the target battleship are established by the 3D Max. The visual simulation of ASM Attack under bearing-only target indication is developed on the EspCreator simulation platform. The shared memory technology is applied in visual scene parameter driving and the technology of integrating DirectX API into scene loop is applied for the real-time simulation of the radar beam. The simulation system can modify the parameters easily and intuitive display simulation results. It’s a new convenient approach for research and evaluation of the weapon application simulation.

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Hingawe, Nilesh D., and Skylab P. Bhore. "Optimal design of surface texture in meso scale air journal bearing." Surface Topography: Metrology and Properties 9, no. 3 (July 7, 2021): 034001. http://dx.doi.org/10.1088/2051-672x/ac0f35.

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42

Liang, Jie, Xiao Fang Xie, Jian Cao, and Xun Qiang Hu. "The Visual Simulation of Air-to-Surface Missile Bearing-Only Attack." Advanced Materials Research 457-458 (January 2012): 872–76. http://dx.doi.org/10.4028/scientific5/amr.457-458.872.

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Yoon, Sang-Joon, Min-Soo Kim, and Dong-Hoon Choi. "Topological design sensitivity on the air bearing surface of head slider." KSME International Journal 16, no. 8 (August 2002): 1102–8. http://dx.doi.org/10.1007/bf02984020.

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Hong Zhu and D. B. Bogy. "DIRECT algorithm and its application to slider air-bearing surface optimization." IEEE Transactions on Magnetics 38, no. 5 (September 2002): 2168–70. http://dx.doi.org/10.1109/tmag.2002.802794.

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SUZUKI, Kenji, Takayuki AKIMATSU, Kenji SASAKI, and Masayuki KURITA. "Design of Structure and Air Bearing Surface for Active Head Sliders." Proceedings of the Conference on Information, Intelligence and Precision Equipment : IIP 2002 (2002): 77–80. http://dx.doi.org/10.1299/jsmeiip.2002.77.

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Shimizu, Yuki, Junguo Xu, Shozo Saegusa, and Noritsugu Umehara. "Air-bearing surface chemical modification for low-friction head–disk interface." Microsystem Technologies 13, no. 8-10 (November 4, 2006): 811–16. http://dx.doi.org/10.1007/s00542-006-0282-0.

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Zhao, Qi, Mingchen Qiang, Yu Hou, Shuangtao Chen, and Tianwei Lai. "Research Developments of Aerostatic Thrust Bearings: A Review." Applied Sciences 12, no. 23 (November 22, 2022): 11887. http://dx.doi.org/10.3390/app122311887.

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In aerostatic thrust bearings (ATBs), a high-pressure gas film with a certain bearing capacity and stiffness is formed by passing high-pressure gas between the moving surface and the static surface. Aerostatic bearings have outstanding advantages in the following aspects: high precision, high speed, and long service life, etc. They are widely used in many fields, such as high-speed air spindles, precision machine tools, air-bearing guideways, turbine machinery, and high-speed drills. With the pursuit of higher efficiency and high-precision machining machinery, there is an increasing demand for high-performance ATBs. Much effort has been spent on the study of ATBs, such as improvements in load capacity and stiffness, and the enhancement of stability. Some significant progress has been achieved. In this paper, the research developments of ATBs are summarized from several aspects, such as theoretical models and experimental methods, static performance, dynamic performance, and applications. In addition, insights on the breakthrough and development trends of ATBs are put forward. It is hoped that this paper can provide some guidance for the design and application of ATBs.

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Tagawa, Norio, and David B. Bogy. "Air Film Dynamics for Micro-Textured Flying Head Slider Bearings in Magnetic Hard Disk Drives." Journal of Tribology 124, no. 3 (May 31, 2002): 568–74. http://dx.doi.org/10.1115/1.1456084.

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This paper describes the air film dynamics for micro-textured flying head slider bearings in magnetic hard disk drives and it discusses their ability to increase the air film damping. In order to study the effects of micro-textures on air film dynamic characteristics of flying head slider bearings, two-dimensional micro-textures are modeled as deterministic rectangular models in the transverse and longitudinal directions. Dynamic analysis of these micro-textured flying head slider bearings is carried out by computing the impulse responses of the sliders and applying the modal analysis method to obtain their modal frequencies, damping ratios, and mode shapes. It is found that micro-textures on air bearing surfaces in the transverse direction have very significant effects and increase the air film damping of the slider’s three vibration modes but do not affect the air film stiffness. The same is not true for micro-texture in the longitudinal direction. The effects of transverse micro-textures’ spacing and depth on the air film dynamics are also numerically investigated in detail. The optimum values for high air film damping ratios are obtained. It is found that transverse micro-textures having small spacing are not very effective, being equivalent to the surface roughness effect.

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Duhri, Rahmat Alfi, Rianto Adhy Sasongko, and Yayom Dwi Laksmana. "Design and Simulation of Air to Air Missile Homing System." INSIST 2, no. 2 (January 25, 2019): 75. http://dx.doi.org/10.23960/ins.v2i2.84.

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This paper will talk about AIM 120 AMRAAM missile guidance for pursuing a moving target. The missile guidance system itself consists of missile dynamics, control system, seeker, and guidance methods. For general purpose, the missile dynamics approach will use non-linear equation of motions. The control surface that will be discussed follow the rule BTT (Bank-to-Turn) and control system that will be used is PID control system that widely used for control design. Lastly, the guidance method that will be studied here is proportional navigation and constant bearing course approach. The simulation will be conducted using MATLAB Simulink. The Simulink model consist of target dynamics, and guidance system. From the result of simulation, it will be shown that the missile can pursue its target quite well. Hence, the simulation system can be used well for preliminary design purpose.Keywords—Homing System, Control System, Proportional Navigation, Missile Dynamics, Seeker, Bank-to-Turn, Constant Bearing Course.

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Ikeda, Kazunori, Toshio Hirano, Tatsuo Yamashita, Makoto Mikami, and Hitoshi Sakakida. "An Experimental Study of Static and Dynamic Characteristics of a 580mm(22.8in.) Diameter Direct Lubrication Tilting Pad Journal Bearing." Journal of Tribology 128, no. 1 (August 19, 2005): 146–54. http://dx.doi.org/10.1115/1.2114929.

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Direct lubrication tilting pad journal bearings (DLTPJ bearings) have rarely been applied to large-scale rotating machinery, such as turbines or generators, whose journal diameters are more than 500mm. In this paper, static and dynamic characteristics of a 580mm(22.8in.) diameter DLTPJ bearing were studied experimentally using a full-scale bearing test rig. In the static test, distribution of metal temperature, oil film pressure, and bearing loss were measured in changing oil flow rate, with mean bearing pressure ranging up to 2.9MPa. The maximum metal temperature of the DLTPJ bearing was compared to that of a conventional flood lubrication bearing, and it was confirmed that the direct lubrication could increase load capacity. In the dynamic test, spring and damping coefficients of oil film were obtained by exciting the bearing casing that was floated by air bellows. These data will be used for analysis and design of steam turbine rotors and their bearing systems. Also, vibration of pads was investigated because metal failure on upper pads due to vibration has been found in some actual machines. In order to generate oil film pressure on the surface of upper pads, a Rayleigh-step was machined there, and it was confirmed that vibration was reduced by the Rayleigh-step.

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Journal articles on the topic 'Air bearing surface'

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