An unusual multistage magnetic gear with
3D printed parts, Neodymium magnets and brushless motor.

The reduction ratio is much higher than a typical series multistage gear with similar stage ratios. A speed and torque analysis reveals large amounts of power circulating back and forth between gear stages.
The analysis shows that the use of Newton's 3rd law in magnetic free body diagrams differ from that of mechanical planetary gears.

0:00 Standard multistage gear demo
2:46 Disassembly
3:43 Compound differential concept (research article)
4:36 Assembly and demonstration
5:59 Speed ratio check and explanation
7:18 Torque analysis- standard multistage
10:13 Torque analysis- compound differential
16:56 Circulating power analysis
20:38 Newton's third law for magnetic gears vs mechanical gears
23:22 Efficiency challenges
24:27 Appropriate application and efficiency remedies


Magnetic gear basics:
   • Magnetic gears : Axial drivetrain pro...  

Referenced research article:
https://bpb-us-e2.wpmucdn.com/labs.ut...