Transaxle Modifications

[RetroZero]

That's the plan on Tuesday. We like complicated over here. So many 'would be DIY' s' are gutted by regulations to make sure no 'backyard garage conversions' happen. All about who is responsable/liable when there is a failure - a piece of certifiable paper covers your ar@#*.... Whilst we think 'common sense', authorities think law suites...' The world of Norms '. No worries, will work out a plan with engineering company next week.

[RetroZero]

To give you an insight into context. In France, conversions can only be done in series - no one offs. The conversion is a certified kit going into a homologated specific model..Modifications to additional vehicle models (which are very similar to original homologated vehicle) will be allowed - at a fee. The 'company' creating the 'kit' is held liable in case of any mechanical failures due to modifications...
My plan is start with Gen 2 inverter, transaxle and battery pack of 250v. Prove that the assembly of parts is according to the original(Prius) so no need for certification, besides the 'lockup gear mod', engine/transale mounting support and a Hubneur/Maguire logic brain approach. If it works here, everyone can profit

[Kevin Sharpe]

To give you an insight into context. In France, conversions can only be done in series - no one offs.

I fully understand the context which is why I advised you to use the homologation services of EV Romania for your first build (which will teach you a lot)

[RetroZero]

Yup, thanks for that. .

[xp677]

Yeah, not sure why this is so difficult, Damien has already posted instructions and a 'how to' video

Ahh, sorry, I see it was planets to carrier, not ring. Makes sense for disassembly. Same principle, though

[RetroZero]

Mock up gear made. Remove planet gears and outer part of their cage is next. Measure thickness required for new part, to simply re-use original planet gear pins to secure a ring gear... More pics to come.

[RetroZero]

Mock up gear 3D printed

[sfk]

This is something to be machined out of steel to drop into the PSD?

[RetroZero]

Machined out of steel.

[kalebludlow]

Machined out of steel.

Looking good. If this works will you share the model? I would much prefer to have a new gear machined than weld the old ones

[NiHaoMike]

If the engine shaft is still connected in that configuration, such a configuration would be useful for converting a Prius transaxle and engine into a backup generator for off grid homes. It could be integrated into a solar/battery setup with much more fine control than what a conventional generator would offer.

[RetroZero]

That's the plan. With such stupid and strict guidelines, I'm trying to find the simplest (cheapest) way, but able to industrialise reproduction for quicker assembly. Will share as I go along. The project is to create as much 'drop in' parts to help safer builds, as controles and laws becomes stricter.

[RetroZero]

The plan is to make a wider gear and spot weld onto carrier..

[RetroZero]

I assume that the oil pump will rotate when Mg1 and Mg2 are locked up via slot at the end of input shaft?

[johnspark]

that is correct RetroZero.

My project has finally started moving again. I have had an axle that mates with MG1 and MG2 directly. My first shaft didn't have a slot for the oil pump, but the company making the shaft have worked out a way to add the oil pump slot.

if you are going to use the spline for output in one of your versions, you will need to calculate torque output. I looked at spline calcs, found there were about 30 parameters to set and gave up. The existing Toyota one can at least carry the torque of the petrol motor.

my shaft has a 25mm output, which is smooth and can carry way in excess of 400Nm.

[RetroZero]

I'll be using as much existing parts as possible. Output shaft splines are not part of the plan(the ones connecting to original engine). The plan is transaxle with battery pack where ICE was, and bolt to original chassis mountings. If Mg's can be coupled and synchronised, we have 80kw... In small city runabouts, that should cover a larger amount of vehicle types

[johnspark]

This graph is my guess of the torque and power outputs:.

I have guessed the generator has a flat torque curve until twice motor speed, because normally the generator travels at twice the speed of the motor.

[RetroZero]

Thanks for that. I'm trying to follow Damiens inverter blow up thread too. If my guess is correct, connecting 200v pack to inverter as intended, requires 400 amps to get 80Kw from transaxle... Normally ICE and MG1 doing the voltage generation, and not battery pack, so very interested in how to work with locking up the Mg's and low voltage pack will turn out...

Are these purely theoretical, based on Toyota info? Cheers

[johnspark]

No worries RetroZero.

So i am hoping to use a 309 volt pack with Gen 3 Toyota inverter, and use the DC DC converter the way it was originally intended. That way the Ldi/dt needs to be less to generate 400 Volts or so for the highest speed. I hope that means less power dissipation in the DC/DC inductor, and that it can cope. Also, the motor won't be able to provide much torque at the higher speeds but will provide back emf that may help the inductor for operating the generator now running as a motor.
Yes, you are right, there are lots of things to test here, so don't know yet if this is going to be successful.

[RetroZero]

Just ordered a planet flange gear as per Toyota parts list. It's the gear connecting MG2 to Planet Carrier, which in turn drives chain and differential.
All my dear ENGINEERS want to know so much about the gear before even looking at it, that I took the initiative to buy the closest possible gear and have it 'slightly' modified...
They require, tooth angle, pitch, depth, clearance, type of (hardened) steel used etc etc....
So, since the Flange Gear is what transfers torque to the wheels (via the chain drive), MG1 and ICE are complimentary and basically provide extra Amps to inverter to keep MG2 happy...I think.
So if MG2 flange can handle 50kW, it can surely manage 30kW from MG1 no?

Will then have the flange gear lined up with pinion and teeth modified to correct depth ....cross fingers there is no COVID 2!!

[RetroZero]

After a long 3 months of finding some one willing to do some "out the box" machining....One "soon to be welded up" Gen2 PSD lock up solution (when in tight regulations situation) is going intoo next phase...
Take one MG2 output gear, machine it along with MG1 output pignon. Then machine the outer carrier to match the MG2 outer teeth (remove 1.5mm).
Then find some nice people to weld it all up ( with a spacer in the middle for some clearance)

[Jack Bauer]

What concerns me the most here is all this work being done without anyone even running one in a car. Doesnt have to be road legal. Throw one in, battery in the back seat and go driving around in a field until something breaks or you run out of charge.

[RetroZero]

Yes, I am getting ahead of myself. Part of the greater plan to prove to authorities that it can be a viable solution here. With "estimated homologation costs around 80 000€" I hope to present an openinverter project with minimal mods.
A locked up PSD, a higher density battery pack around 230v (for single phase home charging) and a nice little black box that does magic tricks.
Cut out as much" jumping through hoops" processes - its stock standard out of already electric car.
It's a risk i'm taking, but I have so much faith in our Japanese friends, thanks to you interpreting their language, it will work .

Got me some 200 volts now, which I'll hook up "progressively". Need to figure out how to recharge it safely and hook up some economisers to Prius relay pack.
Got me a nice Gen2 inverter running MG1 motor in closed loop, but needs tweeking.
So all that's left is a nice little.....VW Polo?
I agree that we need a Gen2 transaxle turning some wheels - soon.

[Kevin Sharpe]

What concerns me the most here is all this work being done without anyone even running one in a car. Doesnt have to be road legal. Throw one in, battery in the back seat and go driving around in a field until something breaks or you run out of charge.

Agreed... if I was developing a product based on this transaxle I'd throw one in a wrecked Prius and run it around the track for a week... we seem to forget the value of testing ideas in the real world

[RetroZero]

I hear you