scholarly journals Magnetic gear with intersecting axes and straight stationary pole-pieces

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401880886
Author(s):  
Xiuhong Hao ◽  
Hongqian Zhu ◽  
Xuemei Guan ◽  
Deng Pan

Based on the magnetic field modulation effect, this article presents a magnetic gear with intersecting axes and straight stationary pole-pieces. Except for a higher utilization of permanent magnets and a greater output torque, the magnetic gear with intersecting axes and straight stationary pole-pieces provides several advantages, such as a smaller volume, higher torque density, and lower processing cost. The magnetic gear with intersecting axes and straight stationary pole-piece topology is herein introduced and the deduced constraints of the structural design are outlined. The transmission mechanism is demonstrated by analyzing the output torque in the middle of the air gaps. The effects of the main design parameters on the maximum static torque are evaluated using the finite element method. Based on the orthogonal experimental design and the response surface method, the optimum design results are provided. Prototype of the magnetic gear with intersecting axes and straight stationary pole-pieces has been realized and the static torque has been verified experimentally.

2020 ◽  
Vol 64 (1-4) ◽  
pp. 771-778
Author(s):  
Yuma Mizuana ◽  
Kenji Nakamura ◽  
Yuma Suzuki ◽  
Yuhei Oishi ◽  
Yuichi Tachiya ◽  
...  

Magnetic gears can change output-torque and -speed without any mechanical contacts. Therefore, they have a low acoustic noise and vibration, and their maintainability and reliability are high. Especially, a flux-modulated type magnetic gear is expected to be put into practical use because its torque density is higher than that of other magnetic gears. For the practical use, further improvement of torque and losses is important, especially, reduction of eddy current loss in permanent magnets (PMs) due to asynchronous harmonic magnetic fluxes is necessary. This paper investigates an interior permanent magnet (IPM) structure to improve the efficiency by reducing the eddy current loss in PMs. In addition, this paper presents a method for increasing torque of the IPM magnetic gear by changing a position of magnetic-bridge.


2012 ◽  
Vol 721 ◽  
pp. 237-242 ◽  
Author(s):  
Masaru Oka ◽  
Takashi Todaka ◽  
Masato Enokizono ◽  
Kousuke Nagaya ◽  
Tomoyuki Fujita

Magnetic gears are a force transmitter consisting of permanent magnets. The mechanical input can be transmitted to an output shaft without contact by magnetic forces. The magnetic gears are not worn out because there is no friction. As a result, the running costs such as the maintenance fee can be suppressed and the resources can be saved. However, the transmission torques of the conventional magnetic gears, which have so far been developed, are very low. Besides, new structure models designed for high torque density need a lot of permanent magnets and multi-pole constructions. Those structures are complex and the manufacturing is difficult. In this research, we applied a flux concentration type surface permanent magnet arrangement to a surface permanent magnet type magnetic gear in order to improve the transmission torque and to reduce the amount of permanent magnets. The magnetic flux distribution, the gap flux density and the transmission torque of the developed new models are numerically analyzed by using the two-dimensional finite element method. In this paper, a permanent magnet structure optimized to reduce its amount and influence of the flux concentration type surface permanent magnet arrangement on the gap flux density distribution and transmission torque are reported.


Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 2003
Author(s):  
Fang Hu ◽  
Yilan Zhou ◽  
Hesong Cui ◽  
Xiao Liu

In order to study the contribution of each harmonic to the output torque and axial torque of the axial magnetic gear with Halbach permanent magnet arrays (HAMG), torque and axial force calculation formulas of the HAMG are proposed based on the air-gap flux density distribution of the HAMG. Because of the difference of the air-gap flux densities at different radii, two simplified torque and axial force calculation formulas are proposed and compared. To improve the torque capability of the HAMG, parametric analysis of eight dimensional parameters is firstly conducted. By parametric analysis, six parameters such as the inner radius have been found to have obvious impact on the output torque and output torque density of the HAMG. The optimization using Maxwell software is then executed for maximizing the output torque density of the HAMG. The output torque density of the optimized HAMG is improved from 78.1 kNm/m3 to 93.3 kNm/m3 with an increase of 19%. Furthermore, spectrum analysis is also presented to illustrate the significant output torque improvement based on the torque calculation formulas.


2013 ◽  
Vol 479-480 ◽  
pp. 230-233
Author(s):  
Yi Chang Wu ◽  
Bo Syuan Jian

This paper presents finite-element analysis (FEA) of the magnetic field of a magnetic gear mechanism. An external type magnetic gear mechanism, which consists of two identical magnetic gears with sector-shaped permanent magnets, is introduced first. Then, the magnetostatic field distribution and transmitted torque of the magnetic gear mechanism are simulated by a commercial FEA package Ansoft/ Maxwell. Next, the effects of design parameters, including the air-gap length, the number of magnetic pole pairs, and the height of permanent magnets, on the maximum transmitted torque are discussed. The results of this work are beneficial to the design of magnetic gear mechanisms.


Author(s):  
Janne E. Heikkinen ◽  
Siavash Pakdelian

Trans-Rotary Magnetic Gear (TROMAG) has recently been introduced as a reliable and efficient way of converting low-speed, high-force translation into high-speed, low-torque rotation, or vice versa. The gear can be used in any high force linear motion application; specifically, it would be a strong contender for wave energy harvesting. The TROMAG consists of two main parts: a rotor and a translator, both of which are formed by furnishing tubular ferromagnetic iron cores with helically-disposed permanent magnets. In this paper, the dynamics of the rotor is studied by employing the Finite Element Method (FEM) and using a simplified model where a flexible rotor is spinning on the flexible isotropic bearings. The rotor system has non-idealities that may excite the system to vibrate. In addition, the non-idealities in geometry cause uneven magnetic pulling force that is considered as an external force. The transient response of the rotor-bearing system is studied by varying the eccentricity of the rotor with respect to the translator. The vibration characteristics of the rotor-bearing system of the TROMAG are evaluated and presented in this paper.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4656
Author(s):  
Yusuf Akcay ◽  
Paolo Giangrande ◽  
Oliver Tweedy ◽  
Michael Galea

Magnetic couplings (MCs) enable contactless speed/torque transmission via interactions between the magnetic fields of permanent magnets (PMs) rather than a physical mechanical connection. The contactless transmission of mechanical power leads to improvements in terms of efficiency and reliability due to the absence of wear between moving parts. One of the most common MC topologies is the coaxial type, also known as the radial configuration. This paper presents an analytical tool for the accurate and fast analysis of coaxial magnetic couplings (CMCs) using a two-dimensional subdomain approach. In particular, the proposed analytical tool resolves Laplace’s and Poisson’s equations for both air-gap and PM regions. The tool can be used to evaluate the impact of several design parameters on the performance of the CMC, enabling quick and accurate sensitivity analyses, which in turn guide the choice of design parameters. After discussing the building procedure of the analytical tool, its applicability and suitability for sensitivity analyses are assessed and proven with the analysis of a fully parameterized CMC geometry. The accuracy and the computational burden of the proposed analytical tool are compared against those of the finite element method (FEM), revealing faster solving times and acceptable levels of precision.


Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3868
Author(s):  
Jiaxing Lei ◽  
Chaofan Wei ◽  
Hui Yang ◽  
Hao Zheng ◽  
Wenjia Wang ◽  
...  

This paper presents general design considerations of a partitioned stator switched flux hybrid magnet memory machine (PS-SF-HMMM). The armature windings and permanent magnets (PMs) are placed on two separate stators, respectively, in the PS-SF-HMMM, and thus both high torque density and wide flux regulation capability can be obtained. The topology and working principle of the machine are introduced briefly first, and then different magnet arrangements and stator/rotor pole combinations are investigated. In addition, various design parameters are optimized based on finite element (FE) methods. Finally, a prototype is fabricated to experimentally validate the FE results.


2001 ◽  
Author(s):  
Moon Kim ◽  
G. K. Ananthasuresh ◽  
Haim H. Bau

Abstract Magnetically actuated diaphragm pumps were fabricated with low temperature co-fired ceramic (LTCC) tapes and Kapton polyimide film. The pumps consisted of a chamber machined in a LTCC substrate. The chamber was covered either on one or both sides with Kapton diaphragms on which copper coils were patterned. The diaphragms were actuated by passing electric current through the coils in the presence of permanent magnets. Passive Kapton flap valves were used to direct fluid flow into and out of the chamber. The first design consisted of a single, circular diaphragm pump. In the second design, two circular diaphragms were used. The two diaphragms are deflected into and out of the pressure chamber simultaneously. Flow rates of up to 7 mL/min were measured. The static response of a circular diaphragm subjected to magnetic forces was computed using the finite element method (FEM). The effect of the copper coils on diaphragm stiffness was accounted for. The design parameters (the number of windings and the size and location of the magnet) needed to maximize the volumetric displacement were determined. At relatively high currents, the coils heated up significantly and caused the pump’s performance to deteriorate.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 1381-1389
Author(s):  
Dezhi Chen ◽  
Chengwu Diao ◽  
Zhiyu Feng ◽  
Shichong Zhang ◽  
Wenliang Zhao

In this paper, a novel dual-stator permanent magnet machine (DsPmSynM) with low cost and high torque density is designed. The winding part of the DsPmSynM adopts phase-group concentrated-coil windings, and the permanent magnets are arranged by spoke-type. Firstly, the winding structure reduces the amount of copper at the end of the winding. Secondly, the electromagnetic torque ripple of DsPmSynM is suppressed by reducing the cogging torque. Furthermore, the dynamic performance of DsPmSynM is studied. Finally, the experimental results are compared with the simulation results.


Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 863 ◽  
Author(s):  
Weiqing Huang ◽  
Mengxin Sun

A piezoelectric actuator using a lever mechanism is designed, fabricated, and tested with the aim of accomplishing long-travel precision linear driving based on the stick-slip principle. The proposed actuator mainly consists of a stator, an adjustment mechanism, a preload mechanism, a base, and a linear guide. The stator design, comprising a piezoelectric stack and a lever mechanism with a long hinge used to increase the displacement of the driving foot, is described. A simplified model of the stator is created. Its design parameters are determined by an analytical model and confirmed using the finite element method. In a series of experiments, a laser displacement sensor is employed to measure the displacement responses of the actuator under the application of different driving signals. The experiment results demonstrate that the velocity of the actuator rises from 0.05 mm/s to 1.8 mm/s with the frequency increasing from 30 Hz to 150 Hz and the voltage increasing from 30 V to 150 V. It is shown that the minimum step distance of the actuator is 0.875 μm. The proposed actuator features large stroke, a simple structure, fast response, and high resolution.


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