Magnetic Gear System Research Articles

Manyetik Dişli Sisteminin Sonlu Elemanlar Yöntemi ile Analizi

The magnetic gear system works with magnetic forces obtained with the help of permanent magnets and has a structure that can be an alternative to classical gear systems. In order to transmit torque between the input and output shaft, unlike conventional gears, there is a transmission without mechanical contact in the magnetic gear system. Therefore, friction is eliminated. Elimination of friction means that magnetic gear systems operate at much higher efficiency compared to conventional gearbox systems. Since the movement and torque transmission in magnetic gear systems occur without contact, it never requires lubrication and problems arising from lubrication do not occur. In conventional mechanical gearbox systems, the conversion rate is determined by the number of teeth used. Similarly in magnetic gear systems, the number of permanent magnets used determines the conversion rate. In this study, a magnetic gear system with a coaxial structure was designed and its electromagnetic analysis was made with the finite element method. Axial torque values at certain speeds in the input shaft and output shaft were obtained as a result of finite element analysis depending on time.

Nonlinear forced vibration of the magnetic gear system with the internal resonance

Considering the nonlinear magnetic coupling stiffness among components of the magnetic gear with intersecting axes and a straight SP (MGIASS), the nonlinear dynamic model and differential equations of the MGIASS system are established. Then, the expression of the forced response is obtained when the excited frequency is close to the torsional mode frequency of the input rotor. The forced responses analysis of the example system shows that: the response frequencies include the excited frequency and the double frequency. Multiple proximity between the natural frequencies directly affects the stability and resonance amplitude.

Nonlinear Resonance Responses of Electromechanical Integrated Magnetic Gear System

Nonlinear differential equations for an electromechanical integrated magnetic gear (EIMG) system are developed by considering the nonlinearity in the magnetic force of the system components. Expressions for the main resonances and superharmonic resonances are obtained for output wave frequencies close to the natural frequency and half the natural frequency of the derived EIMG system. The response laws are discussed in detail. The magnetic coupling stiffness among the components is found to exhibit distinct nonlinearity, leading to strong main resonances and superharmonic resonances. Smaller values of the magnetic coupling stiffness and damping result in larger response amplitudes and transient responses that slowly decay to zero. When the main resonances and superharmonic resonances occur, the dominant frequency of the response is the natural frequency of the derived EIMG system, and the amplitudes of different components of the resonance display large differences.

Cogging Torque Mitigation in Axial Flux Magnetic Gear System Based on Skew Effects Using an Improved Quasi 3-D Analytical Method

Since the flux leakage phenomenon is dominant in the inner and outer radii of axial flux magnetic gears (AFMGs), a prominent overestimation of torque prediction is obtained by the 2-D analytical method (AM) in comparison with the 3-D finite-element method (FEM) simulations. The main motivation of this paper is to present an improved quasi-3-D AM (IQAM), which is an improvement and amendment of the 2-D AM by a simple and effective radial dependence modeling of the axial and tangential magnetic field distribution in AFMGs. This IQAM plays an important role in a reliable and accurate prediction of static and transient behavior of AFMGs. The cogging torque of the AFMG is predicted using the obtained IQAM and Maxwell’s stress tensor. However, the proposed IQAM will become more prominent by focusing on the effects of single- and dual-skews’ designs for ferromagnetic pole-pieces and permanent magnets through suitable step changes in a combined skewed-MG model, as an effective passive method, in order to mitigate the cogging torque and thereby intensively augmenting torque quality in an exemplary AFMG. The accuracy of the developed skewing method is verified using 3-D FEM simulations.

Integrated Multispeed Magnetic Gears: A Novel Approach to Design of Magnetic Transmission Systems

In this paper, a novel approach for the design of magnetic gears is proposed to provide various gear ratios per unit in a magnetic gear system, including a stator, a rotor, and steel segments. This design utilizes rod-shaped permanent magnets in the stator complex instead of arc-shaped permanent magnets used in ordinary magnetic gear systems. Interestingly, the number of pole pairs on a stator is varied only by rotating the rod-shaped magnets. The number of pole pairs on the rotor is kept constant. Therefore, the gear ratio is changed as a function of varying the number of pole pairs on stator. During changing the gear ratio, the number of the steel segments is changed with a specially designed configuration to maintain the maximum efficiency for the system. The concept and working principles of the proposed approach are presented. Simulation studies are employed to validate the performance of the system.

Combination Resonances of Field Modulated Magnetic Gear System Considering Eccentricity

Combination Resonances of Field Modulated Magnetic Gear System Considering Eccentricity

Production of magnetic planetary gear and measurement of basic properties

A non-contact gear mechanism is important for the non-contact transmission of a torque and a motion. In this paper, a magnetic gear system without contact which requires no lubricant oil is proposed. The driving gear consists of some iron discs with gear teeth whose shape is an involute curve. The discs of the follower gear are inserted in the gaps between the discs of the driving gear, and the attractive forces between the discs generate the torque transmission. Using the magnetic gear system, a magnetically connected planetary gear device is developed. Moreover we measure and study the slip torque as static property, and the step-out torque as dynamic property due to implication of rotational speed.

Magnetic coupling studies between radial magnetic gears

The torque of a magnetic gear system with different magnetic poles has been investigated by computer-aided simulation with 2 dimensional modeling processes of finite element analysis. With a fixed separation of distance, the torque shows a maximum for a special number of poles, which shifts to a higher number of poles as the ratio of the radius to the thickness of the magnets increases and shifts to a lower number of poles with addition of an iron yoke. Using this technique, we can obtain an optimum design of a radial magnetic gear system for practical usage.

Torque transfer through plastic bonded Nd 2Fe 14B magnetic gear system

Nd 2Fe 14B plastic bonded magnet segments prepared using the injection moulding technique were magnetised and then assembled in order to form magnetic multipole gear coupling systems. No load measurements were performed using various numbers of poles and various separation distances between the gears. The transmitted torque behaviour is associated with the configuration of the magnitude field distribution between the two multipoles.

Vibration Control Of A Magnetic Gear System By Using Sliding Mode Control

A new magnetic gear system with an actuator made by an electromagnet is proposed. Vibration due to the system parameter variations or external disturbance is absorbed by changing the magnetic fluxes in this electromagnet, and the controller is designed by variable structure system theory. Theoretical expressions for the transmitted torque, magnetic spring constant and control force versus electric current in the electromagnet are derived. Simulations of this magnetic gear system have been carried out by using sliding mode control and the results are compared with those obtained by the PID control method. The experimental results for the sliding mode controller confirm the theoretical analyses.

Robust Control of Magnetic Gear Transmitting System.

A new magnetic gear transmitting system with an actuator made of an electromagnet is proposed in this paper. The vibration due to the system parameter variations or external disturbance is absorbed by means of changing magnetic fluxes of the electromagnet and the controller is designed by variable structure system (VSS) theory. The theoretical expressions of the transmitting torque, magnetic spring constant and control force versus electric current in the electromagnet were derived. Both the simulations and experiments of this magnetic gear system were carried out by means of the sliding mode regulator and were compared with the PID linear control method. The experimental results confirmed the theoretical analyses.