Hi,

I haven't seen a sketch or diagram for the Camry transaxle. I know how our Prius transaxle work and figured the Camry was the same. But someone (not a Prius owner) thinks there is an extra planetary gear in the Camry transaxle and just don't know.

Has anyone seen a paper, maintenance guide or other sketch that shows the parts of a Camry transaxle?

Thanks,
Bob Wilson

 

Hi Bob,

The Camry Hybrid has the reduction gear same as Highlander and RX400h.
http://www.toyota.co.jp/en/tech/environment/powertrain/hybrid/index.htm

Ken@Japan

 

See attached. Page 2 specfically.
J

 

Yes, there are 2 electric motor/generators and 2 planetary gear sets.



Will Mayall

 

Thanks to all who replied! (What a great place, GreenHybrid.com!)

The motor speed reduction gear makes a lot of sense and it appears to be a fixed ratio reduction unit. I can see where it extends the range MG2 can contribute motive force. I've added the "Toyota.pdf" file to my records folder.

It would be misleading to suggest that this fixed ratio, planetary gear has any 'shifting' capability. It is basicly extending the low-end range of the MG2 over a wider speed range. Excellent!

Bob Wilson

 

Very interesting - I did not know a compound gearing was used on the TCH. A tech at the dealer said the TCH uses an isolated cooling circuit for the HSD, independent from the ICE cooling. I am most curious if anyone has any info on the cooling of the TCH. Is the temperature of the HSD lower than the ICE? Heat buildup in the Prius HSD is a limitation and possibly a contributor to the early breakdown of the HSD oil. A few folks have had oil analysis done on the Prius HSD oil at 60K miles, and it showed significant breakdown and loss of viscosity.

 

The second cooling system is for the DC-DC Inverter. An electronic component that potentially can develope a LOT of heat.
J

 

Also note that GS450h and LS600h have two speed (3.9:1 - 1.9:1) variable reduction gearset.
http://priuschat.com/index.php?showtopic=20684&st=10

Ken@Japan

 

Hi,
I can not answer about the TCH system but only the Prius I appears to have the problem. The current model, Prius II, does not have this problem after Toyota added some ball bearings and started using a lower viscosity transmission oil. No doubt the TCH benefits from this 'lessons learned.'

Bob Wilson