Investigation of the Torque Transmission Characteristics in Dual-Flux-Modulated Magnetic Gear

Due to the field-modulation effect, the coaxial magnetic gear (CMG) can achieve a low-speed high-torque transmission. To further improve the torque capability, a dual-flux-modulated CMG (DFM-CMG) derived from conventional CMGs is presented. The DFM-CMG has two rotors, two modulators, and three air gaps. The operation principle and torque transmission are revealed. The air-gap magnetic fields are modulated by the two modulators. The output torque of DFM-CMG can be adjusted by the relative angular displacement between the two modulators. The optimal shift angle of the inner modulator is 0. The DFM-CMG is a combination of CMGs I and II. The CMG I component makes a major contribution to the output capability. The measured pull-out torque of the DFM-CMG prototype is 6.08
$\text{N}\cdot \text{m}$
. It shows a 28.3% growth over CMG I.