Outlander front transaxle and inverter 3D scans?

[OutlandishPanda]

Hi, has anyone taken a 3D scan of the Outlander front transaxle and inverter? Just wondering, before I build basic CAD models to package my Panda.

I've FINALLY got my Outlander front motor and gears turning so getting close to cutting metal...

My plan is to take out the Panda engine and transmission and put in the complete Outlander front transaxle. Not sure yet if I will remove the generator from this lump and make a blanking plate for it, but it is not that simple. It may help the weight distribution after putting 88kg of BMW battery in the boot.

Thanks.

[Bigpie]

I can't help you there are the moment. I could lug mine round to bobby_come_lately when his scanner arrives but that might be a while.

How come you went with the front instead of the rear? The single front motor is pretty weak, I've considered ripping out my gearbox and sticking the Outlander reduction in to use both, would need to look at the internal clutch as I've heard it doesn't engage until a certain speed to allow both units to apply power, and setting off is where I'm missing the umph.

[OutlandishPanda]

Thanks very much, but its not worth that effort - I'll get my tape measure out. I asked just to check it someone had it to hand. I'll share whatever models I end up generating.

Well, it was cheap... And my Panda is tiny and light. Looking at the tractive effort from the Panda's 1.2L engine and the Outlander front Transaxle with the same Panda wheels and tyres, it matches quite well for peak torque:

Assuming my maths was right... It may be a bit more spritely off the line, but no sports car!

[mjc506]

There must be a way of locking that clutch up to get torque from both motors... Although I'm not sure I'd want much more power in a Panda

[Bigpie]

I'd have thought just welding it would work, I would want that much power in my beetle, pulling the gearbox apart is on my todo list at some point to take a look.

[OutlandishPanda]

You've inspired me to test the generator! Yes I can spin that as well thanks to Damian's info here:

https://github.com/damienmaguire/Outlander-PHEV

These drives are very smooth and quiet I think. Anyway, yes, I was thinking about using the generator drive also. I've only 5 BMW 26Ah PHEV modules so I'll quickly hit their current limit, but I'll leave the generator in for now and have a play when the car is moving.

As you know, the clutch is actuated by an oil pump on the driveshaft so beyond a certain road speed it becomes possible to electrically enable the clutch via the electro-hydraulic valve. What the lowest road speed that will work at I don't know, but I think in the original application it is quite a high speed like 60mph?

I think if welded up, that would give a lot of drag when you don't need that additional power. I was thinking of adding a small external electric oil pump. Should be possible to connect up on the end plate some how and enable drive whenever needed:

If that did work, this would make a fairly attractive complete 120kW drive for the price and weight...

But I've got to focus on getting my Panda running first! Too many possibilities!

[mjc506]

I suppose you'd be driving a few extra bearings and the 'generator' if the clutch was welded. You're right though, the pump and valve look to be quite easily accessible, so "how hard can it be"

[tom91]

The main thing to keep in mind, the generator is rpm limited in reverse so you would have to disable the generate inverter section when driving in reverse. That is is the gearbox is mounted in the same way as in the outlander, if its reversed orientation the generator will not be able to provide torque in forward motion.

[OutlandishPanda]

Thanks Tom, do you know what leads to that limitation? I've had the generator accelerating unloaded in both directions, and it makes a slightly difference noise one way compared to the other in testing so far. (Drive motor makes same noise in both directions.) Makes sense, they would have no need to engineer it to work in both directions and could optimise it for one.

[OutlandishPanda]

Found the clutch pressure information and where to apply external electric pump pressure:

[tom91]

Thanks Tom, do you know what leads to that limitation?

Sorry I should have mentioned this is if you run the stock outlander front inverter and firmware on it.

[Bigpie]

Popped the side cover off for a look, not a lot to see.

[OutlandishPanda]

Interesting, thanks. I've built a simple transaxle model in 360 and found a Panda CAD model and it looks like it fits... Just about. Not much room for the inverter - my next challenge.

I'll share the model when I've checked a few more measurements on it.

I think I can achieve equal length driveshafts although I need to put some structure in the vehicle CAD model (I'm not yet ready to take the engine out and try it for real). Does anyone have advice on acceptable drive shaft angle range at rest position? I'm trading off height above the transaxle for the inverter, ground clearance and driveshaft angle. Thanks.

[OutlandishPanda]

Wasn't so easy to make it all fit. The Panda brake booster is rather large and the pipes around the master cylinder are all over the place, which I don't want to touch, but I think I've got it all in. Equal length driveshafts don't seem possible. I might need to extend the inverter<>power cables. I really wanted the DC-DC / Charger in there as well, which is a bit of a squeeze.

I've attached the Fusion 360 models of the Outlander parts if they are any use to anyone.

I should probably start a project page now I'm finally getting to the build stage...

[Bigpie]

Cracked open the main gearbox today. Will try to get in to the clutch a bit further.

[mjc506]

Thanks for those models I like your Panda CAD too!

The gearbox looks nice and clear inside. Tiny clutch, even my little 125 looks like it has a larger dia clutch, although this will have more plates and probably more clamping pressure. And probably doesn't have to manage any slip. Could even be a cone clutch? A good way of transmitting more torque in a small space, but wears quicker when slipping. So does it look like the clutch itself is mechanically activated? Or are there hydraulics inside do you think?

[Bigpie]

Not yet worked out how to get inside. Will update further when I'm in

[mjc506]

Might have to remove those gears, could be a pain

I was just thinking, if it's actually mechanically operated (external solenoid/piston pressing/pulling the central pin on the bearing only side) it might be possible to hold it locked with a simple spacer or similar. Or actually, it looks like there's a flat on the shaft? Perhaps locked/unlocked by turning it. Might be able to drive the stock actuator with an external pump.

EDIT: No, duh.. The flat must drive the hydraulic pump, and I think I can see ports both within the actuator and clutch shaft (between the o-rings) so it'll be hydraulically actuated internal. Makes sense. Should be able to lock it by applying hydraulic pressure to that port (probably not that much pressure either, can't transfer much power with a small flat on that shaft)

[Bigpie]

I think you're right, the shaft drives the pump, it looks to be internally activated. I think it'll be similar to a motorbike clutch pack. I don't have a press to remove the gears if that's required to get in.

Might get someone with a tig to have a go at welding it up while it's out.

[mjc506]

I think I might be tempted to attack the pump instead of the clutch. If you can drill into the pressure line from outside...

[Bigpie]

I cant see a situation where having the clutch welded up would be a drawback. Seems simpler.

[OutlandishPanda]

Looks interesting inside! Thanks for sharing that.

I posted the pressure and external port above to actuate the hydraulic clutch. Welding up certainly simpler, just you may then have a lot more losses at higher speed so may hurt range? Not so much mechanical losses but electrical losses as the PM generator will have to field weaken at high speed so not to "generate" when you are not asking for torque (cruise)? Could be wrong but that was what concerned me with that approach. If it was an induction motor, that would not be a problem I guess.

[Bigpie]

No idea I'm only half considering using it. If anyone wants to take it off my hands, along with the motor I'd quite happily let them go.