The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
T. Nakamura - One of the best experts on this subject based on the ideXlab platform.
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Static tilt characteristics of aerostatic rectangular double-pad Thrust Bearings with double row admissions
Tribology International, 1997Co-Authors: T. Nakamura, Shigeka YoshimotoAbstract:Aerostatic Thrust Bearings have been used in linear guideway systems of various precision measuring apparatus by reasons of low friction, non-hysteresis and high accuracy of motion. In such a case that the measuring systems do not satisfy the Abbe principle, the accuracy of linear guideway systems is greatly influenced by the tilt characteristics in pitch, roll and yaw directions of aerostatic Thrust Bearings. This paper proposes the application of aerostatic rectangular double-pad Thrust Bearings with double row admissions of compound restrictors to the linear guideway systems subjected to tilt moments in both pitch and roll directions, and investigates, theoretically and experimentally, the static tilt characteristics of these aerostatic Thrust Bearings.
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dynamic tilt characteristics of aerostatic rectangular double pad Thrust Bearings with compound restrictors
Tribology International, 1996Co-Authors: Shigeka Yoshimoto, J Tamura, T. NakamuraAbstract:Aerostatic rectangular double-pad Thrust Bearings with compound restrictors have often been used in linear guideway systems of ultra-precision machine tools and precision measuring equipments, because high bearing stiffness is easily achieved in these Bearings. However, in actual devices, various dynamic loads as well as static loads are imposed on these aerostatic Bearings. Therefore, in this paper, the dynamic stiffness and damping coefficient of this type of bearing for tilt motion of a shaft are investigated, both theoretically and experimentally. It was consequently found that the dynamic tilt characteristics of the aerostatic Thrust Bearings considered in this paper are greatly influenced not only by design parameters such as the groove position and the groove depth but also by the squeeze effect.
Shigeka Yoshimoto - One of the best experts on this subject based on the ideXlab platform.
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Static Characteristics of Aerostatic Thrust Bearings With Multiple Porous Inlet Ports
Journal of Tribology-transactions of The Asme, 2015Co-Authors: Takako Hosokawa, Kei Somaya, Masaaki Miyatake, Shigeka YoshimotoAbstract:Aerostatic porous Bearings have been applied successfully to various precision devices, such as precision machine tools and precision measuring equipment, to achieve higher accuracy of motion. Recently, large aerostatic porous Thrust Bearings have been used as essential components in a lithography machine for large liquid crystal display (LCD) glasses. Conventional aerostatic porous Bearings are made of porous material that covers the whole of the bearing surface area, requiring a large piece of such material for large Bearings. However, making large pieces of porous material requires the use of a large electric furnace, which is a very expensive part of the bearing's manufacturing cost. To overcome this problem, this paper proposes an aerostatic Thrust bearing with multiple porous inlet ports. The proposed bearing has a number of small porous inlet ports on the bearing surface, thereby avoiding the need for large electric furnaces. The static characteristics of the proposed Bearings are investigated numerically and experimentally. The results show that the proposed aerostatic Thrust bearing is potentially very useful for the manufacture of large aerostatic Thrust Bearings, where it would have advantages over conventional aerostatic porous Thrust Bearings.
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Static tilt characteristics of aerostatic rectangular double-pad Thrust Bearings with double row admissions
Tribology International, 1997Co-Authors: T. Nakamura, Shigeka YoshimotoAbstract:Aerostatic Thrust Bearings have been used in linear guideway systems of various precision measuring apparatus by reasons of low friction, non-hysteresis and high accuracy of motion. In such a case that the measuring systems do not satisfy the Abbe principle, the accuracy of linear guideway systems is greatly influenced by the tilt characteristics in pitch, roll and yaw directions of aerostatic Thrust Bearings. This paper proposes the application of aerostatic rectangular double-pad Thrust Bearings with double row admissions of compound restrictors to the linear guideway systems subjected to tilt moments in both pitch and roll directions, and investigates, theoretically and experimentally, the static tilt characteristics of these aerostatic Thrust Bearings.
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dynamic tilt characteristics of aerostatic rectangular double pad Thrust Bearings with compound restrictors
Tribology International, 1996Co-Authors: Shigeka Yoshimoto, J Tamura, T. NakamuraAbstract:Aerostatic rectangular double-pad Thrust Bearings with compound restrictors have often been used in linear guideway systems of ultra-precision machine tools and precision measuring equipments, because high bearing stiffness is easily achieved in these Bearings. However, in actual devices, various dynamic loads as well as static loads are imposed on these aerostatic Bearings. Therefore, in this paper, the dynamic stiffness and damping coefficient of this type of bearing for tilt motion of a shaft are investigated, both theoretically and experimentally. It was consequently found that the dynamic tilt characteristics of the aerostatic Thrust Bearings considered in this paper are greatly influenced not only by design parameters such as the groove position and the groove depth but also by the squeeze effect.
J Tamura - One of the best experts on this subject based on the ideXlab platform.
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dynamic tilt characteristics of aerostatic rectangular double pad Thrust Bearings with compound restrictors
Tribology International, 1996Co-Authors: Shigeka Yoshimoto, J Tamura, T. NakamuraAbstract:Aerostatic rectangular double-pad Thrust Bearings with compound restrictors have often been used in linear guideway systems of ultra-precision machine tools and precision measuring equipments, because high bearing stiffness is easily achieved in these Bearings. However, in actual devices, various dynamic loads as well as static loads are imposed on these aerostatic Bearings. Therefore, in this paper, the dynamic stiffness and damping coefficient of this type of bearing for tilt motion of a shaft are investigated, both theoretically and experimentally. It was consequently found that the dynamic tilt characteristics of the aerostatic Thrust Bearings considered in this paper are greatly influenced not only by design parameters such as the groove position and the groove depth but also by the squeeze effect.
Lie Yu - One of the best experts on this subject based on the ideXlab platform.
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Theoretical and Numerical Analysis on the Load Capacity of Hydrodynamic Thrust Bearings with Fourier Series Decomposition
2019 IEEE International Conference on Mechatronics and Automation (ICMA), 2019Co-Authors: Baisong Yang, Sheng Feng, Jiale Tian, Lie YuAbstract:As an indispensable part of modern supporting technology, advanced hydrodynamic bearing still plays an irreplaceable role in turbomachinery. The high-speed turbomachinery in the 21st century still needs stable, low-friction Bearings to support their rotors to run both smoothly and efficiently. Although various types of Thrust Bearings have been investigated in the recent year, they suffer from load capacity and instability problems. Nonetheless, the hydrodynamic bearing current design methodology still dependents on empirical design, lacking corresponding theoretical guidance. There needs to establish a universal rule about topology structure for a variety of non-circular Bearings. The purpose of this paper is to focus on the static characteristics of hydrodynamic Thrust Bearings with topology design theory of Fourier series expansion of film thickness. Firstly, a universal mathematical expression for Thrust Bearings has been put forward based on the Fourier series theory. Secondly, the influence of periodic harmonics of film thickness on the static performance of different types of Thrust Bearings has been studied for the incompressible lubricant. Finally, the relationship between the k-th order harmonic component of the film thickness H0,k and the static pressure component P0,k of Thrust bearing was established for various geometry parameters including the stepped, tapered and tapered-flat type. This method can be used to rapidly estimate the bearing capacity of the component, designed more excellent lubricating film carrier curve to significantly improve its carrying capacity. This new investigation method can be used to improve the performance of the new type of hydrodynamic Thrust Bearings.
Anindya Chakravarty - One of the best experts on this subject based on the ideXlab platform.
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Simulation studies on aerostatic Thrust Bearings with special reference to cryogenic turboexpanders
Indian journal of cryogenics, 2016Co-Authors: Naveen Kumar, Anindya ChakravartyAbstract:The present paper details theoretical studies on aerostatic Thrust Bearings with special reference to cryogenic turboexpander rotors. A special case of 4.5K, 250W helium refrigerator has also been considered where both the turboexpanders are supported by aerostatic Thrust Bearings of similar dimensions. The Bearings experience continuously changing ambient (discharge) pressure during the start-up and shut-down transients, thereby requiring a proper estimation of bearing characteristics for successful turboexpander operation at all times. Performancecharts, intermsofloadcapacity, stiffnessandbearinggasflowwithrespect to change in clearance have been presented for different bearing gas supply and discharge pressures.
