... elastohydrodynamic lubrication hard disk drives lubricants magnetic bearings seals Magnetic torque M × H and viscous torque ( ω p − Ω ) in ferrofluid flow generate the rotational viscosity in ferrofluids [ 1 , 56 , 57 ]. In the presence of the magnetic field, the fluid and particles...

...P. Samanta; H. Hirani The present work portrays the latest review of the progressive advances in passive magnetic bearing (PMB) technology. PMB is an old technology with many encouraging properties. However, there are a number of inherent issues with design, analysis, and performance...

...Zhao Yulan; Liu Xingnan; Yang Guojun; Shi Zhengang; Zhao Lei The high-temperature gas-cooled reactor pebble-bed modular (HTR-PM) has been proposed by the Institute of Nuclear and New Energy Technology of Tsinghua University, in which the active magnetic bearings (AMBs) are equipped to support...

...K. P. Lijesh; Mrityunjay Doddamani; S. I. Bekinal Passive magnetic bearing's (PMB) adaptability for both lower and higher speed applications demands detailed and critical analysis of design, performance optimization, and manufacturability. Optimization techniques for stacked PMB published in recent...

...Yulan Zhao; Guojun Yang; Patrick Keogh; Lei Zhao Active magnetic bearings (AMBs) have been utilized widely to support high-speed rotors. However, in the case of AMB failure, emergencies, or overload conditions, the auxiliary bearing is chosen as the backup protector to provide mechanical supports...

..., a hybrid (hydrodynamic + rotation magnetized direction (RMD) configured magnetic) bearing has been proposed. The hybrid bearing consists of square magnets to repel the shaft away from the bearing bore. Load-carrying capacities of four configurations of hybrid bearings were determined. The results...

... = axial force, N H c = coercive force, A/m K z = axial stiffness, N/m μ r = relative permeability μ 0 = absolute magnetic permeability, H/m References [1] Sotelo , G. G. , Andrade , R. , and Ferreira , A. C. , 2007 , “ Magnetic Bearing Sets...

...Siddappa I. Bekinal; Soumendu Jana This work deals with generalized three-dimensional (3D) mathematical model to estimate the force and stiffness in axially, radially, and perpendicularly polarized passive magnetic bearings with “n” number of permanent magnet (PM) ring pairs. Coulombian model...

... 2015 25 05 2015 Passive magnetic bearing (PMB), made of high remanence rare earth permanent magnets, is brittle in nature; therefore, precautions must be taken to reduce the chances of vibration transmitting to the permanent magnets. In the present work, a rotation magnetized direction (RMD...

...Yulan Zhao; Guojun Yang; Zhengang Shi; Lei Zhao The auxiliary bearing is applied to provide mechanical uphold for the rotational dropping rotor when contact event happens due to the active magnetic bearing (AMB) failure emergencies. During the rotor drop process, the auxiliary bearing will endure...

.... Bearing design Magnetic bearings Active magnetic bearings (AMBs), made of eight poles as shown in the Fig. 1( a ) , find their wider usage in flywheel energy storage systems [ 1 ], turbomolecular vacuum pump [ 2 ], artificial heart blood pump [ 3 ], etc., due to their built-in fault diagnostics...

... have been developed for design and optimization of radial axial polarized passive magnetic bearing (PMB) with single layer for facilitating easy and quick solution, obviating the need of costly software. Seven design variables: eccentricity, rotor width, stator width, rotor length, stator length...

...Antti Kärkkäinen; Marlene Helfert; Beat Aeschlimann; Aki Mikkola Active magnetic bearings present a technology that has many advantages compared to traditional bearing concepts. Active magnetic bearings, however, require retainer bearings in order to prevent damages in the event of a component...

...M. Saint Raymond; M. E. F. Kasarda; P. E. Allaire Rotors supported by active magnetic bearings (AMBs) can spin at high surface speeds with relatively low power losses. This makes them particularly attractive for use in flywheels for energy storage in applications such as electric vehicles...

...Patrick S. Keogh; Woon Yik Yong Under normal operation, a rotor levitated by magnetic bearings will rotate without making contact with any stator component. However, there are a number of circumstances that may lead to temporary or permanent loss of levitation. These include full rotor drop events...

... for publication in the ASME JOURNAL OF TRIBOLOGY . Manuscript received by the Tribology Division March 13, 2003 revised manuscript received September 18, 2003. Associate Editor: L. San Andre´s. 13 March 2003 18 September 2003 28 06 2004 magnetic bearings machine bearings lubrication...

...M. O. T. Cole; P. S. Keogh; C. R. Burrows The dynamic behavior of a rolling element bearing under auxiliary operation in rotor/magnetic bearing systems is analyzed. When contact with the rotor occurs, the inner race experiences high impact forces and rapid angular acceleration. A finite element...