Permanent Magnet Couplings Research Articles

Multi-parameter optimization analysis of permanent magnet couplings using response surface methodology and genetic algorithm

Multi-parameter optimization analysis of permanent magnet couplings using response surface methodology and genetic algorithm

Active Inertia Extended Resonance Ratio Control for Permanent Magnetic Coupling Transmission System

Active Inertia Extended Resonance Ratio Control for Permanent Magnetic Coupling Transmission System

Experimental and theoretical analysis of magnetic-thermal-mechanical coupling of permanent magnet coupling

Experimental and theoretical analysis of magnetic-thermal-mechanical coupling of permanent magnet coupling

Study on Magnetic Field Modeling and Transmission Performance of Radial Solid Permanent Magnet Coupler

Study on Magnetic Field Modeling and Transmission Performance of Radial Solid Permanent Magnet Coupler

A novel key performance analysis method for permanent magnet coupler using physics-informed neural networks

A novel key performance analysis method for permanent magnet coupler using physics-informed neural networks

Electromagnetic analysis and detent force minimization of a linear vernier motor

This paper proposes a new dual-sided linear permanent magnet vernier motor (LPMVM). The advantages of high thrust density, low thrust ripple, positive force elimination and structural stability are introduced in detail. The double-sided structure and toroidal winding proved the novelty of the machine tool, which is suitable for high definition digital control machine tools. Firstly, the basic structure and working principle of the engine are introduced. Through theoretical analysis, the expressions of electromagnetic thrust and detent force are derived. Thirdly, basic characteristics of permanent magnetic magnet flux coupling, backless electromotive force, detent force and electromagnetic drive are analyzed by using a a simplified three-phase model with symmetric boundary in 3-D finite element analysis. Finally, the thrust density and the detent force of the designed motor are calculated and analyzed. The results show that the designed motor is superior to the linear permanent magnet synchronous motor.

Design and development of modular magnetic bio-inspired autonomous underwater robot – MMBAUV

This paper describes the design and construction of a magnetically coupled modular bio-inspired underwater robot named the Modular Magnetic Bio-Inspired Underwater Vehicle (MMBAUV). Designed to form a traveling wave to mimic efficient Body Caudal Fin (BCF) swimming and manoeuvring, its modularity allows for flexible system setup and offers an opportunity for redundancy and cost reduction through a common design structure. The specific feature of this design presents a novel application of a permanent synchronous magnetic coupling between neighbouring modules with a rotational degree of freedom (DoF). The actuated magnetic coupling provides a reliable and low maintenance solution to the fundamental issues of water tightness of flexible underwater structures. When encountering extreme conditions, the magnetic coupling allows the safe decoupling of the modules increasing the survivability of the robotic system. Presented lab testing results demonstrate the function of the design and provide initial evidence of its thrust generation and manoeuvrability.

Influence of structural parameters of cartridge-type synchronous magnetic coupling on transmission performance

The study of the structural parameters of the permanent magnet magnetic coupling is particularly important because they determine its transmission performance. In this paper, we first compare and analyze the results of theoretical calculation and simulation, and conclude that the calculation results of the 3D simulation model are closest to the actual situation. Maxwell software is used to study the effect of the cartridge type synchronous permanent magnet coupling on the transmitted torque at different working air gaps, permanent magnet thickness, yoke thickness, and aspect ratio under different pole numbers. The results show that: the increase of working air gap is not conducive to increasing the transmitted torque; the increase of permanent magnet thickness is beneficial to increase the transmitted torque, but the increase rate gradually decreases; the increase of yoke thickness has a small increase on the magnetic torque within a certain range, and the yoke thickness is slightly larger than the permanent magnet thickness is optimal; the increase of permanent magnet’s aspect ratio also increases the torque, and the torque density growth rate is the fastest when the aspect ratio is in the range of 0.5~0.7. Through the analysis, it is important for the design of synchronous magnetic coupling and other researches.

A fast and accurate solution to optimal design of eddy-current PMCs with standard disc type

Although permanent magnet couplings (PMCs) have been under research for many years and have found successful industrial applications, this is still a technology under development. Accurate parameter determination is of significance for performance analysis and critical decisions on PMC design. However, the determination can often lead to an unacceptable increase in computation, especially when the finite element (FE) method is used. The study aims to develop an FE model that is used for the structural design of a standard-disc type PMC for optimal torque. For the quick and accurate design, an integration optimal solution of the response surface methodology (RSM) and the Taguchi’s method was proposed. To verify the simulation, a series of experimental investigations were conducted on a self-developed testing platform. Furthermore, for a minimum set of FE analyses (FEA), a quantitative indicator called contribution rate, which can reflect effect level of structure parameters on the torque, was given based on the Taguchi method. Apart from this, the orthogonal matrix was used for the reduction of the FE calculation. Based on the contribution rate, the response surface methodology was adopted for the optimal torque determination with no increase in the PM volume. According to the optimization results, a fitting formula, which considers the contribution rates of the optimization variables, was presented. The results suggest that the FE simulations agree very well with the experiments, and the fitting formula can be used in the PMC design.

Research on magnetic field analytical modeling and transmission characteristics of squirrel cage asynchronous permanent magnet coupling

Research on magnetic field analytical modeling and transmission characteristics of squirrel cage asynchronous permanent magnet coupling

Development of Axial-Flux Single-Drive Bearingless Motor With One-Axis Active Positioning

This study proposes a novel axial-flux bearingless permanent magnet motor with one-axis active positioning. This bearingless motor consists of an axial-flux surface permanent magnet motor with coreless coils and a repulsive permanent magnet coupling located at its center. Therefore, it has a single three-phase winding and needs only one three-phase inverter for both rotation and magnetic suspension; it is, thus, referred to as a single-drive bearingless motor. The axial position of the rotor is actively controlled, whereas the radial and tilting motions are passively stabilized. The suspension force and torque are regulated by the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> -axis and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">q</i> -axis currents, respectively. The structure of the proposed axial-flux single-drive bearingless motor is presented, and its torque and suspension force are obtained by both theoretical derivation and numerical modeling (using the finite-element method). A prototype machine is fabricated, and the obtained experimental results are presented and discussed.

Theoretical Computational Model for Cylindrical Permanent Magnet Coupling

Permanent magnet coupling is extensively studied owing to its economic efficiency and stability. In this study, a computational model for cylindrical permanent magnet coupling (CPMC) was designed using the magnetic field division method to divide an air gap magnetic field. An equivalent magnetic circuit model was also designed based on the equivalent magnetic circuit method. The novelty of this study is that both the skin effect and the working point of the permanent magnet are taken into consideration to obtain the magnetic circuit and induce eddy current characteristics of permanent magnet coupling. Furthermore, a computational model was obtained for the transmission torque of the CPMC based on the principles of Faraday’s and Ampere’s laws. Additionally, the accuracy of the model was verified using a finite element simulation model and a test bench.

Demonstration of a 220-GHz Continuous Wave Traveling Wave Tube

The 220-GHz continuous wave (CW) folded waveguide (FWG) traveling wave tube (TWT) is presented as the high-power amplifier for the terahertz (THz) communication system in this article. This tube is designed and fabricated including FWG circuit, electron gun, periodical permanent magnet system, coupling window, and thermal management structure. The test results show that with the pencil beam of 20.5 kV and 52.4 mA, the output power is 16 W and the corresponding bandwidth is 7 GHz from 213 to 220 GHz, and the maximum power and the corresponding gain are 30 W and 31.2 dB at the frequency of 217 GHz.

Application and Innovative Design of Permanent Magnetic Coupler Drive

Application and Innovative Design of Permanent Magnetic Coupler Drive

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

This paper presents magnet shape optimization of permanent magnet coupling (PMC) for a 50 hp chemical pump system considering the linear and non-linear design parameters. Firstly, the size and topology of PMC are considered for the initial model. PM eddy currents are analyzed to select the initial model. Secondly, an optimization process is performed to get the maximum pullout torque for a given PM volume. The optimization is based on a two step process; firstly, non-linear design parameters are considered for optimization using 2-D finite element method (FEM). The optimization is performed to maximize the pullout torque of the PMC and reducing the PM volume. Kriging method and genetic algorithm are utilized due to the non-linearity of the design parameters in the optimization process. Secondly, linear design parameters are adjusted and 3-D FEM is utilized to achieve the target and incorporate the end effects. Using two-step design process, the number of design parameters are reduced in the first step which simplify the optimization process and computational time is reduced using 2-D FEM. After that, the axial length of the PMC can be used as a linear design parameter to obtain the required pull-out torque. The optimized model is then simulated using 3-D FEM to incorporate the end effects and experimental results are then presented.

Analytical Modeling and Design of Novel Conical Halbach Permanent Magnet Couplings for Underwater Propulsion

Permanent magnet couplings can convert a dynamic seal into a static seal, thereby greatly improving the stability of the underwater propulsion unit. In order to make full use of the tail space and improve the transmitted torque capability, a conical Halbach permanent magnet coupling (C-HPMC) is proposed in this paper. The C-HPMC combines multiple cylindrical HPMCs with different sizes into an approximately conical structure. Compared with the conical permanent magnet couplings in our previous work, the novel C-HPMC has better torque performance and is easy to process. The analytical calculation method of transmitted torque of C-HPMC is proposed on the basis of torque calculation of the three common types of HPMCs. The accuracy of the torque calculation of the three HPMCs is verified, and the torque performance of the three HPMCSs of different sizes is compared and discussed. The “optimal type selection” method is proposed and applied in the design of C-HPMC. Finally, on the basis of torque analysis calculation and axial force calculation, a complete flowchart of the design and performance analysis of C-HPMC is described.

Optimization of a 3D-Printed Permanent Magnet Coupling Using Genetic Algorithm and Taguchi Method

In recent decades, the genetic algorithm (GA) has been extensively used in the design optimization of electromagnetic devices. Despite the great merits possessed by the GA, its processing procedure is highly time-consuming. On the contrary, the widely applied Taguchi optimization method is faster with comparable effectiveness in certain optimization problems. This study explores the abilities of both methods within the optimization of a permanent magnet coupling, where the optimization objectives are the minimization of coupling volume and maximization of transmitted torque. The optimal geometry of the coupling and the obtained characteristics achieved by both methods are nearly identical. The magnetic torque density is enhanced by more than 20%, while the volume is reduced by 17%. Yet, the Taguchi method is found to be more time-efficient and effective within the considered optimization problem. Thanks to the additive manufacturing techniques, the initial design and the sophisticated geometry of the Taguchi optimal designs are precisely fabricated. The performances of the coupling designs are validated using an experimental setup.

Semi-Analytical Model for Temperature Estimation of Permanent Magnet Couplers

Temperature estimation is highly significant in the design stages and analysis of permanent magnet (PM) machines. In this paper, for permanent magnet couplers (PMCs), a semi-analytical model to estimate the temperature is developed, which is able to give consideration to efficiency and applied in more complicated structure. Also, the magnetic flux path, as well as the eddy currents, are depicted through a simplified geometric topology. Moreover, the eddy current loss, taken as the heat source loss, is effectively and quickly calculated by employing magnetic equivalent circuit and Kirchhoff's law. Compared with the experimental results, this model has a good agreement with the experimental results where the deviation is within 6.67%. Finally, some constructive suggestions have been given for prediction, optimization and monitoring of PMCs.

Thermal Analysis Strategy for Axial Permanent Magnet Coupling Combining FEM with Lumped-Parameter Thermal Network

Thermal analysis is exceptionally important for operation safety of axial permanent magnet couplings (APMCs). Combining a finite element method (FEM) with a lumped-parameter thermal network (LPTN) is an effective yet simple thermal analysis strategy for an APMC that is developed in this paper. Also, some assumptions and key considerations are firstly given before analysis. The loss, as well as the magnetic field distribution of the conductor sheet (CS) can be accurately calculated through FEM. Then, the loss treated as source node loss is introduced into the LPTN model to obtain the temperature results of APMCs, where adjusting conductivity of the CS is a necessary and significant link to complete an iterative calculation process. Compared with experiment results, this thermal analysis strategy has good consistency. In addition, a limiting and safe slip speed can be determined based on the demagnetization temperature permanent magnet (PM).

The Analysis of Thermal Magnetic Coupling of Tubular Permanent Magnetic Coupler

Due to the existence of induced eddy current, the internal of the permanent magnet coupling’s temperature increases during the operation, which affects the performance of the permanent magnet coupling. In this paper, considering the influence of temperature on the remanence, coercive force of the permanent magnet, the conductivity of the conductor and steel frame. We analysed the coupling performance of thermodynamics and electromagnetism. Electromagnetic field simulated with ANSYS Maxwell and temperature field simulation with Workbench. The analysis results lay a foundation for the subsequent analysis of the thermo-magnetic coupling of the permanent magnet couplings.