Dual Magnetic Gear for Improved Power Density in High-Gear-Ratio Applications

Park, Eui-Jong; Kim, Chan-Seung; Jung, Sang-Yong; Kim, Yong-Jae

doi:10.23919/icems.2018.8549367

Cited by 9 publications

(3 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One method to keep high torque density at high gear ratio is to use the harmonic or cycloid MGs having a single layer of air gap. The other method is to use the multistage FMMGs that can be built by simply connecting single-stage ones in series as shown in Figure 26 [114,115] or by the compound differential pattern as shown in Figure 27 [116]. The latter is able to offer gear ratio higher than that of the former but suffers circulating power flows leading to poor efficiency.…”

Section: Gear Ratiomentioning

confidence: 99%

A review on the field‐modulated magnetic gears: Development status, potential applications, and existent challenges

Yan,

Li,

Wang

et al. 2023

IET Electric Power Appl

View full text Add to dashboard Cite

As a type of magnetic device being able to realize contact‐free power transmission together with sufficient volumetric torque density, the field‐modulated magnetic gear (FMMG) has become a promising alternative to the mechanical gear having rigid construction yet suffering lots of issues generated by the continuous teeth friction. The conventional magnetic gears (MGs) that behave as simple copies of their mechanical counterparts and can be roughly defined as origination of the FMMG are briefly introduced at first. Subsequently, the topology and material advancements proposed to improve operational performance of the FMMG are comprehensively summarised so as to clarify its current development status. Finally, potential applications of the FMMG due to its inherent advantages are compared against the existent challenges. The review aims to provide referable guidelines for researchers working at the field of high‐performance MGs.

show abstract

Section: Gear Ratiomentioning

confidence: 99%

A review on the field‐modulated magnetic gears: Development status, potential applications, and existent challenges

Yan,

Li,

Wang

et al. 2023

IET Electric Power Appl

View full text Add to dashboard Cite

show abstract

“…Torque is transmitted by mutual interaction of magnetic fields generated by permanent magnets and steel segments. MGs have become more and more attractive due to their many advantages, such as their precise torque transmission capability, reduced maintenance, reduced vibrations and lower levels of acoustic noise, the absence of direct mechanical contact between rotors, inherent overload protection and improved overall reliability over the operational life of a device (Mateev and Marinova, 2020;Jing et al, 2019;Park et al, 2018;Zhou et al, 2020). However, MGs use soft magnetic materials and a large number of permanent magnets to obtain high magnetic torque.…”

Section: Introductionmentioning

confidence: 99%

Modelling of low-speed magnetic gear with viscose ferrofluid

Mateev

Marinova

2022

COMPEL

View full text Add to dashboard Cite

Purpose In this paper, a computational model of a coaxial magnetic gear (MG) design with viscose ferrofluid between rotors is proposed. Viscose ferrofluid is used to decrease the magnetic reluctance and therefore creates higher magnetic torque. However, viscose friction of ferrofluid is undesirable and must be minimised in this particular application. MG is supposed to operate under low rotational speeds, where the dynamic viscose friction is very low, and the effects of the viscose ferrofluid over the MG’s efficiency must be estimated. The paper aims to analyze the performance of MG with viscose ferrofluid and to estimate the MG efficiency by computational model using finite element method (FEM). Design/methodology/approach An MG design with viscose ferrofluid between the outer low-speed rotor and modulating steel segments was modelled as a coupled transient magnetic field problem and a kinematic model with viscous friction coefficients derived from a previously computed fluid dynamics model. Findings The proposed computational implementation is suitable for homogeneous magnetic fluid modelling in electromagnetic actuators and rotational machines. The results regarding power and torque transmission of MG were obtained by coupled finite element modelling. The efficiency of MG significantly decreased due to ferrofluid friction. Originality/value The described MG design with viscose ferrofluid is a novel device with new operational characteristics, and new results for the effects of viscose ferrofluid friction in the outer magnetic field over the MG efficiency are estimated.

show abstract

“…Even though CMG has become very well known to designers, researches are mainly focused on torque multiplier type, where gear ratio is set at > 1 [12][13][14][15][16][17][18][19]. Noticeably, there are limited publications that discuss the topic of speed multiplier where the gear ratio is set at < 1 [20][21][22].…”

Section: Introductionmentioning

confidence: 99%

A New Speed Multiplier Coaxial Magnetic Gear

Halim¹,

Sulaiman²,

Firdaus³

et al. 2020

PIER M

View full text Add to dashboard Cite

Due to certain conditions, electrical motor (EM) that operates at high speed may lead to magnetic saturation, thermal issue, and stress to rotor structure. Magnetic gear (MG) designed for speed multiplier enables the prime mover from EM to operate at lower speed while the output gear multiplies the speed by its designated gear ratio at reduced torque. In this paper, a new coaxial magnetic gear is designed for speed multiplier. The role between inner yoke with PM and pole piece is switched. The inner part of magnetic gear is made to be stationary while the pole piece becomes inner rotor. The working principle is presented analytically based on flux modulation techniques for torque and speed transmission. Torque characteristic and gear efficiency are analysed using finite element and compared with existing speed multiplier magnetic gear with the same gear ratio of 7/3. Based on the simulation result, the proposed speed multiplier MG offers 16% better torque density and 12% higher gear efficiency at higher speed range. The structure of the inner rotor is also found to be more robust as only pole piece ring together with plastic holding frame is rotated instead of yoke with PM.

show abstract

Dual Magnetic Gear for Improved Power Density in High-Gear-Ratio Applications

Cited by 9 publications

References 8 publications

A review on the field‐modulated magnetic gears: Development status, potential applications, and existent challenges

A review on the field‐modulated magnetic gears: Development status, potential applications, and existent challenges

Modelling of low-speed magnetic gear with viscose ferrofluid

A New Speed Multiplier Coaxial Magnetic Gear

Contact Info

Product

Resources

About