Magnetically geared conveyor drive unit - an updated version

This paper presents an updated design of a magnetically geared drive unit for chain conveyor applications. The magnetic gear is placed partially inside the sprocket that drives the chain, and the permanent magnet synchronous machine driving the gear is placed axially next to the gear. The first version suffered from very large rotational losses leading to poor efficiency and thermal problems which limited the drive unit to a very low speed if continuous operation were to be sustained. Furthermore, due to a bad pole configuration, large cogging torque was seen on the HS rotor. This paper presents an updated version where the primary focus is to show, that both cogging torque and rotational losses can be reduced to an acceptable level. With a reduction of the rotational losses by a factor of 4.6 and a peak-to-peak cogging torque which has been reduced substantially, the main goals have been achieved. The mechanical integration is also simplified and manufacturability is improved.