Joined
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77 Posts
Greetings all.
If you haven't read
http://www.toyota.co.jp/IRweb/special_r ... rts_12.pdf
please take the time to do so.......very interesting and well laid-out. A question I have concerns the power split device. The attachment included shows the ICE, generator, motor and power split device. Toyota explains that there is a linear relationship between the rpm's of the three gears in the planetary gear arrangement (see drawings labeled "Colinear graphing of planetary gear relationships" in the aforementioned pdf). Looking at these drawings, it appears (and makes good sense) that at any one moment, any one of the three component gears (the sun gear connected to the generator, planetary gear carrier connected to the ICE and the ring gear connected to the motor/power shaft) could be motionless while the others are spinning. The power shaft could keep the ring gear motionless via the parking brake mechanism as is the case when the ICE is running to charge the battery when parked. The ICE compression could keep the planetary carrier motionless during stealth mode but I'm not sure that compression alone is used. I have no idea what would keep the sun gear motionless during normal driving when no electricity is being generated. Could it be that the sun gear is never motionless or is there some kind of clutch/braking element that would hold it motionless thereby putting all available power generated by the ICE and motor to the power shaft? Either way, what a great and simple system!
Also, I'd like to see the shaft arrangement that connects the ICE to the planetary gear carrier. I can't quite visualize how it works as it passes through the generator.
These Toyota engineers are to be commended!
If you haven't read
http://www.toyota.co.jp/IRweb/special_r ... rts_12.pdf
please take the time to do so.......very interesting and well laid-out. A question I have concerns the power split device. The attachment included shows the ICE, generator, motor and power split device. Toyota explains that there is a linear relationship between the rpm's of the three gears in the planetary gear arrangement (see drawings labeled "Colinear graphing of planetary gear relationships" in the aforementioned pdf). Looking at these drawings, it appears (and makes good sense) that at any one moment, any one of the three component gears (the sun gear connected to the generator, planetary gear carrier connected to the ICE and the ring gear connected to the motor/power shaft) could be motionless while the others are spinning. The power shaft could keep the ring gear motionless via the parking brake mechanism as is the case when the ICE is running to charge the battery when parked. The ICE compression could keep the planetary carrier motionless during stealth mode but I'm not sure that compression alone is used. I have no idea what would keep the sun gear motionless during normal driving when no electricity is being generated. Could it be that the sun gear is never motionless or is there some kind of clutch/braking element that would hold it motionless thereby putting all available power generated by the ICE and motor to the power shaft? Either way, what a great and simple system!
Also, I'd like to see the shaft arrangement that connects the ICE to the planetary gear carrier. I can't quite visualize how it works as it passes through the generator.
These Toyota engineers are to be commended!