Coupling Electric Motor with Gearbox (Version 1)
I combined in the first version of the Mini the existing gearbox with the help of a timing belt with the electric motor. An oil-pump was added to supply the different gear pinions with transmission oil. Due to the removal of the clutch shifting of gears is only possible in standstill. I drive mostly in the 3rd gear since the electric motor has enough torque to accelerate the Mini reasonably form standstill up to 80km/h – the maximum speed in this 3rd gear is 120km/h. In case I have to climb really steep slopes I switch previously to 2nd gear (Switzerland ;-).
I am currently preparing an update of the solution and intend to remove the gear pinions by a single shaft which forwards the torque from the asynchronous motor directly to the differential in the gearbox housing. See some further information in the sections below.
Coupling Electric Motor with Gearbox (Version 2)
A part of this project was to reverse engineer the gearbox and do the entire design with the help of CAD.