The Experts below are selected from a list of 9522 Experts worldwide ranked by ideXlab platform
Lei Mei - One of the best experts on this subject based on the ideXlab platform.
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Research status and development of permanent magnet biased Magnetic Bearings
Diangong Jishu Xuebao Transactions of China Electrotechnical Society, 2009Co-Authors: Xu Sheng Zhao, Zhi Quan Deng, Xiao-lin Wang, Lei MeiAbstract:Permanent magnets biased Magnetic bearing is an important research content in high speed application field such as flywheel energy storage and turbo molecular pumps etc. In this paper permanent magnets biased Magnetic bearing's research status now and development in the future are expounded. Permanent magnets biased Magnetic Bearings are sorted as axial single degree of freedom (DOF) Magnetic bearing, radial two DOF Magnetic bearing, axial-radial three DOF Magnetic bearing and five DOF Magnetic bearing system. Their configurations are studied. Their sketch maps are presented. Their operating principles are analyzed through using Magnetic circuit maps. Same type's Magnetic Bearings are compared and where they can be applied is pointed out. Many permanent magnets biased Magnetic Bearings' configurations are advanced. Permanent magnets biased Magnetic Bearings with low power consuming, simple structure and easy controlled will be a primary researching direction.
Cheol-hoon Park - One of the best experts on this subject based on the ideXlab platform.
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High-Precision Roller Supported by Active Magnetic Bearings
Applied Sciences, 2019Co-Authors: Cheol-hoon Park, Tae Gwang Yoon, Dongwoo Kang, Hugo RodrigueAbstract:Magnetic Bearings support rotors in a non-contact way using Magnetic force. Therefore, there is no friction and it is possible to measure and control the position of a rotor in the air gap. In this study, the rotational vibration of a roller was minimized using Magnetic Bearings, and a precision roller capable of automatic alignment using the position control function of Magnetic Bearings was proposed. A rotation accuracy of approximately 4.6 μm (peak-to-peak) was observed, even under a rotation of 30 rev/min and a radial force load of 300 N. The rotor position control experiment for Magnetic Bearings showed that 1-μm resolution position control is possible. To further improve the accuracy, the automatic alignment algorithm was proposed using Magnetic Bearings for the roller misalignment condition, and it was confirmed that alignment is possible at a level that the pressing force difference between both ends of the roller is within 0.3 N. Through this study, it was confirmed that rollers with Magnetic Bearings can be applied to precision equipment. It is expected that the implementation of the automatic alignment function will simplify the equipment configuration and maintenance compared to conventional rollers with ball Bearings.
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Design of Magnetic Bearings for turbo refrigerant compressors
Mechanics & Industry, 2014Co-Authors: Cheol-hoon Park, Sang Kyu Choi, Sang-yong HamAbstract:Magnetic Bearings are oil-free Bearings that are widely employed in turbo machineries such as turbo refrigerant compressors in order to eliminate lubrication systems, avoid contamination, and increase efficiency. We have developed a 145 refrigerant ton (RT)-class turbo refrigerant compressor using homopolar-type radial hybrid Magnetic Bearings (HMBs) and thrust Magnetic Bearings. The thrust mag- netic bearing comprises a thrustHMB and a permanent magnet that generate downward forces to overcome high upward thrust forces of 2000 N at 21 000 rpm. A test rig and controller for the compressor with Magnetic Bearings were fabricated, and rotordynamics such as the unbalance response and axial displacement were investigated. Rotordynamics analyses using the finite element method predicted that the 1st bending mode is located at a high frequency with sufficient margin from the operating speeds. Further, the zero-to-peak displacement caused by the unbalanced response was sufficiently small. The rotor was stably supported with few vibrations across the entire range of the operational speeds. Our results demonstrate that the advantages of oil-free Bearings can be easily exploited in turbo machineries such as turbo refrigerant compressors by adopting HMBs.
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Design of hybrid Magnetic Bearings for turbo refrigerant compressor
17th International Congress on Sound and Vibration 2010 ICSV 2010, 2010Co-Authors: Cheol-hoon Park, Sang Kyu Choi, J. Y. Park, D.w. YunAbstract:145RT class turbo refrigerant compressor using oil-free bearing is under development. For turbo refrigerant compressor, oil-free bearing has merits that the continuous operation is possible because the lubrication system is not need and the refrigerant is not contaminated by the oil. Magnetic bearing is one of oil-free bearing and recently it started to be applied to a few turbo refrigerant compressors because of easy maintenance thanks to no friction and no wear in bearing. This paper presents the design procedure of Magnetic Bearings for turbo refrigerant compressor which consist of hybrid homopolar type radial Bearings and hybrid thrust bearing using both of permanent magnet and electromagnet. Magnetic Bearings are designed to support 2,000N thrust force by compressor at 21,000rpm operating speed. The controller for Magnetic bearing was designed and the rotordynamics such as critical speed, and unbalance response in case that the rotor is supported by Magnetic Bearings are simulated by using finite-element method.
Xu Sheng Zhao - One of the best experts on this subject based on the ideXlab platform.
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Research status and development of permanent magnet biased Magnetic Bearings
Diangong Jishu Xuebao Transactions of China Electrotechnical Society, 2009Co-Authors: Xu Sheng Zhao, Zhi Quan Deng, Xiao-lin Wang, Lei MeiAbstract:Permanent magnets biased Magnetic bearing is an important research content in high speed application field such as flywheel energy storage and turbo molecular pumps etc. In this paper permanent magnets biased Magnetic bearing's research status now and development in the future are expounded. Permanent magnets biased Magnetic Bearings are sorted as axial single degree of freedom (DOF) Magnetic bearing, radial two DOF Magnetic bearing, axial-radial three DOF Magnetic bearing and five DOF Magnetic bearing system. Their configurations are studied. Their sketch maps are presented. Their operating principles are analyzed through using Magnetic circuit maps. Same type's Magnetic Bearings are compared and where they can be applied is pointed out. Many permanent magnets biased Magnetic Bearings' configurations are advanced. Permanent magnets biased Magnetic Bearings with low power consuming, simple structure and easy controlled will be a primary researching direction.
Elisabeth Olivierrulliere - One of the best experts on this subject based on the ideXlab platform.
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stacked structures of passive Magnetic Bearings
Journal of Applied Physics, 1991Co-Authors: Jeanpaul Yonnet, Guy Lemarquand, Sophie Hemmerlin, Elisabeth OlivierrulliereAbstract:The stiffness of Magnetic Bearings composed of only two permanent magnet rings is limited. To increase this stiffness, stacked structures are used. Conventional stacking is obtained by placement of the magnetizations in opposition. This article presents another type of stacking with rotating magnetization direction (RMD), which improves the stiffness by about a factor of 2 in comparison with the conventional stack.
Kenzo Nonami - One of the best experts on this subject based on the ideXlab platform.
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Research Trends on Magnetic Bearings
Jsme International Journal Series C-mechanical Systems Machine Elements and Manufacturing, 2003Co-Authors: Yohji Okada, Kenzo NonamiAbstract:Use of Magnetic Bearings for high-speed rotor and application in clean environment or in special circumstance have been gradually increasing. This article overviews research trends and application presented before the Eighth International Symposium on Magnetic Bearings (ISMB-8). Interesting research topics are the combined realization of motor and Magnetic bearing, low loss Magnetic Bearings and self-sensing techniques. New application fields include small spindles for data storage devices, energy storage flywheels, and artificial heart pumps. Various new technologies are reported related to these new application fields.
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Research trends on Magnetic Bearings: Overview of the 8th International Symposium on Magnetic Bearings (ISMB-8)] : Special issue on Magnetic bearing
Jsme International Journal Series C-mechanical Systems Machine Elements and Manufacturing, 2003Co-Authors: Yohji Okada, Kenzo NonamiAbstract:Use of Magnetic Bearings for high-speed rotor and application in clean environment or in special circumstance have been gradually increasing. This article overviews research trends and application presented before the Eighth International Symposium on Magnetic Bearings (ISMB-8). Interesting research topics are the combined realization of motor and Magnetic bearing, low loss Magnetic Bearings and self-sensing techniques. New application fields include small spindles for data storage devices, energy storage flywheels, and artificial heart pumps. Various new technologies are reported related to these new application fields.
