Design Optimization for Pullout Torque Improvement of a Magnetic Coupling in Chemical Pump Application

Abstract This paper presents a design optimization of an axial-flux eddy-current magnetic coupling. The design procedure is based on a torque formula derived from a 3D analytical model and a population algorithm method. The main objective of this paper is to determine the best design in terms of magnets volume in order to transmit a torque between two movers, while ensuring a low slip speed and a good efficiency. The torque formula is very accurate and computationally efficient, and is valid for any slip speed values. Nevertheless, in order to solve more realistic problems, and then, take into account the thermal effects on the torque value, a thermal model based on convection heat transfer coefficients is also established and used in the design optimization procedure. Results show the effectiveness of the proposed methodology.

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Design Optimization of Magnetic Coupling Using Genetic Algorithm and 2D FEM Model

Fracture Methodologies and Manufacturing Processes ◽

10.1115/pvp2004-2313 ◽

2004 ◽

Author(s):

Petr Krejci ◽

Cestmir Ondrusek

Keyword(s):

Genetic Algorithm ◽

Design Optimization ◽

Permanent Magnets ◽

Magnetic Coupling ◽

Optimization Procedure ◽

Magnetic Characteristics ◽

Fe Model ◽

Fem Model ◽

Additional Advantage ◽

Torque Transmission

Magnetic couplings (Figure 1) are widely used to torque transmission between two shafts without any mechanical contact. They are especially well suited for used in hazardous environments, to transmit torque through a separation wall. An additional advantage of a magnetic coupling is that slipping occurs when excessive torque is applied, this can be used to prevent mechanical failure due to torque overloads. This paper deals with influence of temperature on behavior of magnetic coupling and magnetic coupling design optimization. The permanent magnets that are used for torque transmission cannot be used close to Currie point, which is a point of loss of magnetic characteristics. We intend to use the magnetic coupling for pump of radioactive liquid materials for transmutation devices, where the temperature is close to four hundred centigrade. Because of we suggest the design changes for elimination of temperature influence. This paper presents the finite element (FE) parametric model of magnetic coupling, experimental verification of FE model and optimization of the inner part of magnetic coupling in order to increase the maximal torque. The genetic algorithm method in connection with FEM model of magnetic coupling was used for the design optimization procedure.

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Grain separation enhanced magnetic coercivity in Pt/Co multilayers.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151027 ◽

1993 ◽

Vol 51 ◽

pp. 1038-1039 ◽

Cited By ~ 1

Author(s):

G.A. Bertero ◽

R. Sinclair

Keyword(s):

Remanent Magnetization ◽

Strong Influence ◽

Uniaxial Anisotropy ◽

Magnetic Coupling ◽

Recording Media ◽

Magnetic Media ◽

Signal To Noise ◽

Out Of Plane ◽

Longitudinal Recording ◽

The Relationship

Pt/Co multilayers displaying perpendicular (out-of-plane) magnetic anisotropy and 100% perpendicular remanent magnetization are strong candidates as magnetic media for the next generation of magneto-optic recording devices. The magnetic coercivity, Hc, and uniaxial anisotropy energy, Ku, are two important materials parameters, among others, in the quest to achieving higher recording densities with acceptable signal to noise ratios (SNR). The relationship between Ku and Hc in these films is not a simple one since features such as grain boundaries, for example, can have a strong influence on Hc but affect Ku only in a secondary manner. In this regard grain boundary separation provides a way to minimize the grain-to-grain magnetic coupling which is known to result in larger coercivities and improved SNR as has been discussed extensively in the literature for conventional longitudinal recording media.We present here results from the deposition of two Pt/Co/Tb multilayers (A and B) which show significant differences in their coercive fields.

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Imaging magnetic microstructure with SEMPA

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010015099x ◽

1993 ◽

Vol 51 ◽

pp. 1032-1033

Author(s):

M. H. Kelley ◽

J. Unguris ◽

R. J. Celotta ◽

D. T. Pierce

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Scanning Electron Microscopy ◽

Sandwich Structure ◽

Magnetic Coupling ◽

Polarization Analysis ◽

Secondary Electrons ◽

Magnetic Microstructure ◽

Escape Depth ◽

Scanning Electron

By measuring the spin polarization of secondary electrons generated in a scanning electron microscope, scanning electron microscopy with polarization analysis (SEMPA) can directly image the magnitude and direction of a material’s magnetization. Because the escape depth of the secondaries is only on the order of 1 nm, SEMPA is especially well-suited for investigating the magnetization of ultra-thin films and surfaces. We have exploited this feature of SEMPA to study the magnetic microstrcture and magnetic coupling in ferromagnetic multilayers where the layers may only be a few atomic layers thick. For example, we have measured the magnetic coupling in Fe/Cr/Fe(100) and Fe/Ag/Fe(100) trilayers and have found that the coupling oscillates between ferromagnetic and antiferromagnetic as a function of the Cr or Ag spacer thickness.The SEMPA apparatus has been described in detail elsewhere. The sample consisted of a magnetic sandwich structure with a wedge-shaped interlayer as shown in Fig. 1.

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