Has anyone used one of these yet?
Or know more about them?
I guess they are the same or similar to the RX400 ones from what I can see.
I've also been looking about and there is the suggestion that these transaxle motors operate on 650V despite the main battery pack being a nominal 288V.
Re: Toyota MGR Rear Traction Transaxle
Posted: Wed Sep 25, 2019 10:46 pm
by sfk
Toyota/Lexus like to use moderately low battery pack voltages (around 250V) and boost that to high voltage (around 600V) to operate the electric motors. This is done in the inverter/buck-boost/DCHV-DCLV unit.
I'm not aware of anyone using these motors on this forum, but there may be other projects on other forums.
I'm intrigued by their potential but have a different project that requires a different sort of drive unit.
Re: Toyota MGR Rear Traction Transaxle
Posted: Thu Sep 26, 2019 6:59 am
by Jack Bauer
Please don't lets get hung up on this high voltage thing. Motors don't care about voltage. They care about current. More voltage is only required to counter the back emf as the motor increases speed. Toyota only boost the voltage when needed, not all the time.
Re: Toyota MGR Rear Traction Transaxle
Posted: Thu Sep 26, 2019 8:34 am
by Mouse
Jack Bauer wrote: ↑Thu Sep 26, 2019 6:59 am
Please don't lets get hung up on this high voltage thing.
True enough but I'm guessing running it from ~300V it will have have about half the speed and power capability?
Jack Bauer wrote: ↑Thu Sep 26, 2019 6:59 am
Toyota only boost the voltage when needed, not all the time.
That is interesting to know.
Has anyone found any data or performance charts for these?
Re: Toyota MGR Rear Traction Transaxle
Posted: Thu Sep 26, 2019 9:32 am
by Mouse
sfk wrote: ↑Wed Sep 25, 2019 10:46 pm
I'm not aware of anyone using these motors on this forum, but there may be other projects on other forums.
I've not found a lot anywhere about them. Hence joining in the conversation here as at least there is a forum section for the Lexus cars that have them. Plus I've been following Johannes Youtube channel for a while.
sfk wrote: ↑Wed Sep 25, 2019 10:46 pm
I'm intrigued by their potential but have a different project that requires a different sort of drive unit.
Yea same here, they appear to be a capable slight weight drive unit for a smaller vehicle and also not fetching premium prices on the second hand market which are both of interest to me. I've worked with DC traction motors in kitcar conversions a few years ago but am still reasonably new to the capabilities and performance of three phase traction motors motors.
Jack Bauer wrote: ↑Thu Sep 26, 2019 6:59 am
Please don't lets get hung up on this high voltage thing.
More voltage is only required to counter the back emf as the motor increases speed.
True enough but I'm guessing running it from ~300V it will have have about half the speed and power capability?
No. Not necessarily.
To make reasonable comparison of a motors application for a particular job, one needs to look at the output parameters. ie: the torque, speed maximums, and power.
EV AC drive motors are designed over a wide range of voltages and current for relatively similar speed and torque output. Rated nominal operating voltage doesn't educate a guess on how the motor will perform.
Caveat;
Motors designed for high power output, are generally designed for higher voltages. When one is designing an electric drivetrain higher voltages are a common decision made by engineers to maintain operating currents within reasonable limits.
As JB said, it's a matter of current, not voltage.
Re: Toyota MGR Rear Traction Transaxle
Posted: Tue Oct 15, 2019 7:41 am
by Jack Bauer
Just picked up one of these on Ebay for 200 Euros delivered:) 2007 RX400h
Re: Toyota MGR Rear Traction Transaxle
Posted: Tue Oct 15, 2019 10:29 am
by Mouse
Jack Bauer wrote: ↑Tue Oct 15, 2019 7:41 am
Just picked up one of these on Ebay for 200 Euros delivered:) 2007 RX400h
SNAP!!
Jack, Are you planning on doing any speed vs rpm measurements as information appears to be a bit thin on the ground for these motors?
I paid £100 and collected it at the weekend.
It was sold to me as a "LEXUS RX 400H 2004-2008 209048010 "
It has 2FM on the casting and what looks like a barcode and serial number sticker.
Has anyone identified replacement connectors for the resolver and temp sensor?
Trying to decide if something like an inverter from a 2015 Yaris would be a suitable donor to power it as they are common and inexpensive.
I also guess they are more compact and a bit smaller than the Mk2 Prius inverters?
The tyres on a RX400h are 235/65R18 and have a rolling circumference of 2.396M.
When the MGR is at 4,000prm the output shafts are at 583rpm.
The car will be doing 84KPH.
At 100KPH the MGR will be doing 4,771rpm.
Conclusion: You could use this unit to drive a vehicle at highway speeds if 100Nm of torque and 50Kw of power is sufficient. Either you have a light vehicle, you're not obsessed with acceleration, or you use 2 MGR's in 4WD configuration. The RX400h inverter can easily drive 2. Or even 3 if that makes sense somehow.
That's exciting! The units are so small and not transverse in orientation.
Re: Toyota MGR Rear Traction Transaxle
Posted: Sat Oct 19, 2019 4:28 am
by Pajo_16
Updated my post above to backup the unsubstantiated power curve with data from the lexus.co.uk homepage. The data seems to correlate.
Re: Toyota MGR Rear Traction Transaxle
Posted: Sat Oct 19, 2019 11:38 am
by Kevin Sharpe
sfk wrote: ↑Sat Oct 19, 2019 3:56 amConclusion: You could use this unit to drive a vehicle at highway speeds if 100Nm of torque and 50Kw of power is sufficient. Either you have a light vehicle, you're not obsessed with acceleration, or you use 2 MGR's in 4WD configuration. The RX400h inverter can easily drive 2. Or even 3 if that makes sense somehow.
That's exciting! The units are so small and not transverse in orientation.
Worth remembering that my VW Bus was rated at 40 kW (54 PS; 54 bhp) DIN when it left the factory in 1967
Re: Toyota MGR Rear Traction Transaxle
Posted: Sat Oct 19, 2019 12:04 pm
by johu
We are considering an Audi A2 conversion here, trying to stay below the ICEs power for ease of registration. This could be the perfect solution. Would a Prius inverter do it justice?
Re: Toyota MGR Rear Traction Transaxle
Posted: Sat Oct 19, 2019 4:24 pm
by arber333
johu wrote: ↑Sat Oct 19, 2019 12:04 pm
We are considering an Audi A2 conversion here, trying to stay below the ICEs power for ease of registration. This could be the perfect solution. Would a Prius inverter do it justice?
I am quite sure Prius inverter would excell. Remember it did not use full amp rating on its IGBTs for weakening a high speeds, but rather it boosted voltage to raise RPM at the same KV. If you would use FW then you bypass boost stage and use some motor cooling for highway speeds.
EDIT: I was thinking for those dedicated drive applications, wouldnt it be better to just connect inductor input and boosts top transistor to completely bypass boost drive? What would Prius say to that???
Still in A2 i think the easiest solution would be to just use Prius transaxle with PSD welded to sun gear. Cooling is there, plenty of power for quick starts and you dont need to tell TUV inspector you use the second motor .
Comparing the RX300h to RX450h the performance improvement 'appears' to minimal based on the current cost difference. Some searching I fond the RX450h MGR to be approximately 3x the cost of the RX300h MGR. As always prices vary and if you can get your hands on an RX450h MGR at the same price as a RX350h MGR then go for it!!
.