Detail of stator and rotor assembly Where two young, intrepid engineers attempt to electrify two bicycles for under $200 using an odd motor without any magnets.

Goals

  • Electrify two bicycles for under $200 each
  • Demonstrate axial-flux switched-Reluctance motor technology
    • Using hubmotor built into rear wheel
    • Using motor driving a chain or belt on rear wheel

Preliminary model of SRM hubmotor

The switched reluctance motor

Switched reluctance motors rely on the electromagnetic attraction of ferromagnetic materials (such as steel) to an applied magnetic field, instead of relying on permanent magnets or magnetic induction.

Advantages

  • Can be made cheaper due to the lack of permanent magnets
  • No detent torque (cogging) from permanent magnets

Challenges

  • Axial flux-type motors are relatively rare for switched-reluctance motors
  • Control technology is still somewhat undeveloped (leads to characteristic V8 sound)

Preliminary work

  • Preliminary CAD of hubmotor: Detail of entire motor assembly Detail of stator and rotor assembly Detail of stator assembly

Useful Technical Documents