Drive Unit Assembly

Drive unit: Motor combined with old gearbox

Bommy (see comments) asked my to explain how I did the coupling of the old gear box with the electric motor. I added some further pictures under the tap “drive train”, which show how it was done http://www.bdrive.ch/ev-conversion/drivetrain/.

Basic Idea

The basic idea was to insert a new shaft in place of the old crank shaft which supports and holds the old input pinion exactly at the same position as it was before. The input pinion was then coupled with a tooth belt pulley so that the electric motor can drive the gear. Sound as it was a piece of cake – but it wasn’t!

A Challenge – hot Bearings and Input Pinion

There were several small challenges. E.g. I tried to run in a first approach the new shaft and its greased bearings and the old input pinion without active oiling. But during first runs the outcome was that the pinion and  shaft bearings got too hot due to the friction (input to 2nd pinion) and fast turning of the shaft (grease). Luckily a colleague of mine – crazy chap who restores in his spare time old Range Rovers – helped me to add an oiling system. We placed an additional oil pump which provides the bearings and the input pinion with oil. Now the drive unit runs soothly and very efficient.

Remark

I’ve seen other solutions how to couple motor and gearbox of the Mini. For instance a solution where the electric motor was directly coupled with main axle of the gear box. This is a very smart and compact design with less turning parts. It needs no additional shaft, input and 2nd pinion nor oiling system. However I do not know how the sealing of the axle was done so that no oil leaks out of the gear box. If there is someone out there who  knows how to dot it then please let me know …. ;-).

Happy New Year  …  Erich Butler

Approval for Road Use

License plate number: LU135719

Finally I managed to get the approval and the official license plate on Wednesday 13th December 2017.  I am very happy that everything went well in the second round. The chief expert tested the Electric Mini even on the motorway and reached a maximum speed of 120 km/h.

This is the link to the corresponding agency / authorities: strassenverkehrsamt.lu.ch

 

 

So far I did some test runs in Lucerne and its surrounding. I can summarize the first impressions and outcomes as follows:

Consumtion0.16 kWh/km
Range (calculated with consumption and battery capacity)65 km
Acceleration / SpeedNo problem to follow traffic
Problems1.) Voltage drop during heavy acceleration in 3rd gear. Converter starts to limit.
2. ) Battery pack needs to be better balanced

Keep you posted ….. take care …. Erich Butler

Final Acceptance

Waiting ……

On the 6th December 2017 the time finally came and we (the garage owner helping me with the mechanics and I) showed the Mini to the authorities. After a two hours inspection by the  chief expert himself we got a tentative OK for the use of public roads.
There was only a minor issue with the hand brake and that’s why we have to show the car again this Wednesday. I hope that everything goes well I can drive home with the Mini with the official vehicle’s registration plate.

 

Start of acceptance tests

I have to admit that the Department of Transportation of the Canton Lucerne was very open and supportive. This helped a lot to get the approval.

Keep you posted …. cheers Erich

Ready for the official Acceptance by the Authorities

I have not written for a longer time. I was absorbed with some family affairs and hobby priority #1 was to finish the car. Now the car is almost ready for the official acceptance by the authorities of the Kanton Luzern in Switzerland. I sent them a report with all technical details and got a first feedback (some remarks), but overall the green light to show the car the in the upcoming weeks. Keep you posted ….. cheers Erich