For those who love to calculate gear ratios, here's some teeth counts for you. Power Split Sun Gear: 30 Power Split Pinion Gear: 23 Power Split Ring Gear: 78 Motor Speed Reduction Sun Gear: 22 Motor Speed Reduction Pinion Gear: 18 Motor Speed Reduction Ring Gear: 58 Counter Gear (replaces chain) Drive Gear Teeth: 54 Couter Gear Driven Gear Teeth: 55 Final Gear Drive Gear: 24 Final Gear Driven Gear: 77 Total Final Drive Ratio: 3.267:1 And for kicks, the Transmission weighs (fully filled) 92kg or 202.8lbs Fluid is still type WS and at 3.0L (3.2 qts). There is no specified replacement interval in the maintenance guide.
Thank you! This matches my expectation. This allows calculation of MG1 maximum power (unless you happen to have it too.) Bob Wilson ps. I called Toyota Technical Information System, 1-800-622-2033, and they report the repair manuals should be available in about 3-4 weeks.
Actually the NCF only specifies power for MG2. Another interesting note: MG1 is liquid cooled, while MG2 is only air cooled. Lubrication is sling style w/ an upper oil catch basin with a drain that drips lubrication to other essential parts. Bob, you really should review the NCF. TIS is $10/day for another few days, then goes to $15/day. :-D
Thanks for the 'heads up' but being an old and forgetful guy, "NCF?" Is this the "New Car Features" document? Is there a Toyota part number on it? What I have been discussing in "Prius Technical Stuff" is the recent SAE paper 2009-01-0726, "Development of New Hybrid Transmission for Compact-Class Vehicles", Mizuno, Ibaraki, Kondo, Odaka, Watanabe, Mizutani, Kaneshige and Kitada. Bob Wilson
Rick, I think it is going to $15 for two days, they are doing away with the one day option. So it'll cost less per day but more overall...
You are correct! Column 1 Column 2 Column 3 Column 4 0 Type 2 Day* Monthly Yearly 1 Standard [/B]$15 US [/B]$75 US [/B]$400 US 2 *Now a Two Day term! That's only $7.50/day! Unfortunately monthly is going from $50 to $75 and yearly, $350 to $400. Technically, each time I've gotten the 1 day, it ends up being almost 2 anyway as they don't expire it till midnight the day after purchase. i.e. I bought yesterday evening, and my sub isn't expiring till tonight, which is giving me time to grab a few more things.
I found a real nice animation, interactive too. I get a message I can't post URLs until I have 5 posts ... This is only my third post.... guess I have to pick up the pace. How about it, does anyone want to see a real nice interactive animation of the Prius PSD?
If you have a different one than these two, please post.... when you can. Toyota Prius - Power Split Device A simulation of Prius's Planetary Gear
The first one of yours is the one I was referring to. I couldn't find anything like that on this forum. Did I miss it, or is it not here? It certainly is something that I found interesting and informative. When people compare the Prius and the Insight, much is similar. But the 'transmission' is one place they are very different. I recently saw the photos and principle of operation of the Insight "CVT" or "Honda Multimatic" transmission. I read words like "smooth" and "high reliability and durability", but I do not the other words like "metal belt" and "pulleys". This is similar to a snowmobile power train. After reviewing both approaches, I like what the Prius has done. :thumb:
Hi HTMLSpinnr, Are those teeth counts for the PSD quite right? I would expect Ring = Sun + 2*Pinion, and 30+2*23=76 not 78. (I believe that's the rule, from thinking it through. I've found a few places where are allusions to it, but they don't make it clear that it's a hard-and-fast rule.) Your counts for the speed reduction gear work out OK - 22+2*18=58. So would you mind just stripping down your PSD again and checking?! Many thanks.
I had same feeling as yours, however all documents from Toyota for Gen1 through Gen3 shows 30:23:78. Ken@Japan
Ha ha... no stripping down, just pulled from the Toyota docs. And way to dig up an old thread! Bumped it over to the Technical forum where it really belongs (but didn't exist when I first posted).
"Ring = Sun + 2*Pinion, and 30+2*23=76 not 78 was expected" But if you account that in the ring gear and sun gear teeth the contact area changes (also the contact radius) it is perfectly possible.
Right you are! The rule is hard-and-fast because it is just plane geometry. The diameter of the ring gear is equal to the diameter of the sun gear plus 2 times the diameter of a planetary pinion. And pi times those diameters means that the circumferences of the circles of contact also obey that equation. You can measure those circumferences in inches, centimeters, or whatever, and it is still true. So measure them in 'teeth' since all the gears must have the same pitch size for the planetary gear system to mesh. This implies that the Toyota documentation is wrong. You-Tube videos do show that the sun and ring gear tooth counts are correct. So the planetary pinions MUST have 24 teeth each, not 23. It would be nice if someone with a disassembled PSD would confirm it. Or tell us why geometry and algebra don't apply.
