I didn't want to post on the other motor stacking threads but I'm now starting on this conversion! It's going to be a long term project, probably over several (2-3 years) as I can't afford the batteries at the moment. But what I can do is build the motor and get it running on the bench with an IMA drive.
My desired specs.
1) 4 or 5 stacked IMA motors. I already have four and will have another one in a couple of weeks.
2) Insight drive electronics, 4-5 parallel mdm's or similiar. ( I have 3 currently)
3) Batteries A123 60-65S x 4-5P 20kwh pack (Might have to go cheaper in the end)
4) Batteries will all live in IPU box. Drive electronics will be in custom box on top of motors.
5) Insight DC-DC and 3kw charger will possibly live behind seat panel
Once the motor is built i shall drive it on bench with just a single motor powered. Once in the car i shall start with one motor operating and bring the others on stream one at a time measuring performance/heating etc as we go to get some proper performance data. We might find that 2 IMA motors is more than enough for a simple conversion.
Anyway I have dissasembled my 4 IMA motors and the casings have gone off today to the machine shop for the cable inlet to be machined off to allow stacking. I'll then do some measurements and discuss with the engineer how to proceed.
Has anyone else got any progress to report on there own stacked IMA motor threads?
Once the motor is built i shall drive it on bench with just a single motor powered.
When this happens, could you take voltage measurements at the stator cables? I have a theory there should be about 450V during drive instead of the 150-180v from the battery.
Good luck Peter. I like the idea of using IMA components to turn the car electric. I didn't post earlier because I don't have any ideas about mounting them together and you already know my enthusiasm of converting to electric through you previous EV conversion thread and PMs from earlier this year. I'll be watching your progress closely.
The four machined casings will be back Monday so tuesday am hoping to actually stack them together to see what inter stator clearances are like. I'm going air cooled but havent decided how to do it yet. I hope to have five motors in the stack but will settle with four if space is tight.
The machined 4 cases are back i have one more motor to come which will be available after 4th July.
So five stacked in total.
A few discoveries.
1) They will stack together without problems of stator/rotor clearance.
2) The cases outer profile do not match exactly face to face in two small areas. This is not a problem you can see it in the second photo.
Thinking about ease of assembly I think I am going to retain the clutch for mating with the gearbox and commutation sensor. This means the Motor (5th) on the left will be assembled exactly as in the car and mate in the same way. I am going to have a bearing support plate between the 4th and 5th motor see gap in the photo and a thrust type main bearing at the other end on another machine plate which will also have the engine mounting.
Hope that makes sense. My photos only show 4 motors but you get the idea.
Clutch -> Ima Motor x 1 -> Bearing Plate -> IMA motor x 4 -> Thrust main bearing plate and eng mount.
As we have a nice flat surface on the top of the motors a large machined plate will sit on top for drive packages with cable holes direct into tops of motors. So main cable runs will be very short from each drive igbt to motor terminals.
Very nice to see them fitting together so well. 5 electric rotors, looks like a whole bunch of motor in comparison to the 3 cylinders, should be mighty fun to drive with definitely more performance than stock.
Peter: Good to see you getting into your EV project. Assembly of my own stacked motor has been on hold for the last month or more but should get going again after the holidays.
Aluminum filled 2 part epoxy will solve the gap problem. Lay case on flat surface covered with poly film and apply epoxy to the well cleaned case surface. A shaped mold/dam is packed with the epoxy. A coat of car wax on the mold will allow you to reuse it. Be sure to wear gloves to protect your hands.
With the bearing plate on the side of the case that bolted to engine block, you will have to provide relief for the protruding stator assembly (beyond case) which could require considerable recess machining in the plate or an additional gasket-like spacer.
Your numbering of the stacks starts at what was the engine end, mine starts at the transmission end. Probably has something to do with UK right hand drive cars.
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UK Insight EV Conversion
