Dynamics of active magnetic thrust-bearings.

Fukata, Satoru; Kouya, Yoshinori; Shimomachi, Takashi; Mizumachi, Yutaka; Kuga, Makoto

doi:10.1299/kikaic.56.1524

Cited by 4 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The form derived theoretically from Maxwell's equations is given by (2) [7]. The method presented here is an alternative approach to modeling the magnetic control force with a first order time lag as presented by Fukata, Kouya, et al [8] ( 2)where 3The frequency dependent permeability is used in the calculation of the magnetic circuit path reluctance. Fig.…”

Section: Tangential Flux Thrust Bearingmentioning

confidence: 99%

Comparison of the dynamic response of radial and tangential magnetic flux thrust bearings

Kenny

Palazzolo²

2002

IEEE/ASME Trans. Mechatron.

View full text Add to dashboard Cite

Theoretical predictions were made for the dynamic performance of a tangential flux magnetic thrust bearing. A prototype bearing was built with the stators and rotors made from tape wound strip. The performance of this bearing was measured and compared to the theoretical predictions and also to the performance of a radial flux thrust bearing. Tangential flux bearings are intrinsically amenable to construction from tape wound cores. Tape wound cores come in high saturation alloys like supermenduer which can give the bearing a high force to size ratio. The thin tape laminates give the bearing a broad frequency bandwidth. By comparison it is shown that it is difficult to make a laminated rotor magnetically efficient for radial flux bearings. A test rig is described that was built to measure the performance of the tangential flux bearing. A power amplifier with current feedback provided dc and harmonic current to the coils. A load cell was built into the test rig to measure the axial thrust, an inductive/hall sensor was included to measure the coil current, and a hall probe to measure the gap flux. Index Terms-Magnetic bearing, magnetic circuit, tape wound core. NOMENCLATURE Half pole face area. Laminate thickness or thinnest dimension of flux path. Denominator terms. Stacking factor. Magnetic force per stator. Magnetic flux. Coil current. Path length. Coil inductance. Inductive parts of laminate reluctance. Number of poles per stator. Numerator terms. Turns per coil times bias current. Turns per coil times control current. Permeability of metal. Permeability of air. Relative permeability of metal Permeability normal to laminations. Permeability tangential to laminations. Density of laminate metal.

show abstract

Section: Tangential Flux Thrust Bearingmentioning

confidence: 99%

Comparison of the dynamic response of radial and tangential magnetic flux thrust bearings

Kenny

Palazzolo²

2002

IEEE/ASME Trans. Mechatron.

View full text Add to dashboard Cite

show abstract

“…As a result, to predict the dynamic operating characteristics is necessary to avoid costly trials. A few simple dynamic models including eddy currents are described for magnetic actuators [19][20][21][22][23][24][25]. The finite element method (FEM) is also used to analyze the eddy-current effects on the active thrust MBs.…”

Section: Introductionmentioning

confidence: 99%

Modeling and Analysis of Coupling Performance of Dynamic Stiffness Models for a Novel Combined Radial‐Axial Hybrid Magnetic Bearing

Han

Zheng

2014

Mathematical Problems in Engineering

View full text Add to dashboard Cite

The combined radial-axial magnetic bearing (CRAMB) with permanent magnet creating bias flux can reduce the size, cost, and mass and save energy of the magnetic bearing. The CRAMB have three-degree-of-freedom control ability, so its structure and magnetic circuits are more complicated compared to those of the axial magnetic bearing (AMB) or radial magnetic bearing (RMB). And the eddy currents have a fundamental impact on the dynamic performance of the CRAMB. The dynamic stiffness model and its cross coupling problems between different degrees of freedom affected for the CRAMB are proposed in this paper. The dynamic current stiffness and the dynamic displacement stiffness models of the CRAMB are deduced by using the method of equivalent magnetic circuit including eddy current effect, but the dynamic current stiffness of the RMB unit is approximately equal to its static current stiffness. The analytical results of an example show that the bandwidth of the dynamic current stiffness of the AMB unit and the dynamic displacement stiffness of the CRAMB is affected by the time-varying control currents or air gap, respectively. And the dynamic current stiffness and the dynamic displacement stiffness between the AMB unit and the RMB unit are decoupled due to few coupling coefficients.

show abstract

“…Certainly, some excellent analytical methods have been given out for non-laminated structures. Fukata et al [8] analysed the dynamics of an MTB using a linear model in considering of the effect of eddy current. In this model, the eddy current was simplified to be a one-loop circuit and the skin effect was ignored.…”

Section: Introductionmentioning

confidence: 99%

Calculation of eddy current loss for magnetic thrust bearings

Tian

Sun

2011

Proceedings of the Institution of Mechanical Engineers, Part J:

View full text Add to dashboard Cite

A magnetic circuit model of eddy current loss for a magnetic thrust bearing (MTB) is presented based on the effective reluctance and the magnetic circuit theorem. Considering the skin effect of eddy current, the effective reluctance is introduced into the flux path, and the magnetic flux, coil impedance and eddy current loss are analysed. In addition, a harmonic analysis on the finite element method model of the MTB and the magnetic circuit model is conducted and the results are compared in consideration of such affecting factors as material non-linearity, leakage, and fringing flux. It shows that the magnetic flux and the coil impedance have the same frequency domain properties in the above two models. The eddy current losses derived from these two models agree well with the experimental results.

show abstract

Dynamics of active magnetic thrust-bearings.

Cited by 4 publications

References 0 publications

Comparison of the dynamic response of radial and tangential magnetic flux thrust bearings

Comparison of the dynamic response of radial and tangential magnetic flux thrust bearings

Modeling and Analysis of Coupling Performance of Dynamic Stiffness Models for a Novel Combined Radial‐Axial Hybrid Magnetic Bearing

Calculation of eddy current loss for magnetic thrust bearings

Contact Info

Product

Resources

About