Posted by Allen on October 18, 2006, 11:03 pm
Dick Byrd wrote:
> The reason that the ICE just revs up with no power being delivered when
> the main battery fails, is because the delivery of power to the ring gear of
> the Power-Split-Device (and to the wheels) is dependent on there being power
> delivered to MG-1 to counter the torque of the ICE. Otherwise the Sun gear
> just spins and no torque is delivered to drive the car.
> Dick
Thanks for that explanation, I have been trying all day to figure out
why the ICE behaved the way it did when the battery failed.
Will the newer Prius fail in the same manner if the main battery is
lost?
Allen
Posted by richard schumacher on October 19, 2006, 9:51 am
> Dick Byrd wrote:
> > The reason that the ICE just revs up with no power being delivered when
> > the main battery fails, is because the delivery of power to the ring gear of
> > the Power-Split-Device (and to the wheels) is dependent on there being power
> > delivered to MG-1 to counter the torque of the ICE. Otherwise the Sun gear
> > just spins and no torque is delivered to drive the car.
>
> Thanks for that explanation, I have been trying all day to figure out
> why the ICE behaved the way it did when the battery failed.
>
> Will the newer Prius fail in the same manner if the main battery is
> lost?
Yes. The mechanism is substantially the same.
Posted by Dick Byrd on October 20, 2006, 3:31 am
Allen:
Yes, this inherent in the design of the Power Split Device of the Hybrid
Synergy Drive, and it works this way for all Prius models.
It is very hard to explain in words just how this planetary gear train
works, but it can be seen, with a really terrific description, at Graham
Davies web site at: http://www.jantzen.nl/prius/Techniek/
Click on the Power Split Device page and you can study his moving diagrams
and descriptions for hours.
Dick
> Dick Byrd wrote:
>> The reason that the ICE just revs up with no power being delivered when
>> the main battery fails, is because the delivery of power to the ring gear
>> of
>> the Power-Split-Device (and to the wheels) is dependent on there being
>> power
>> delivered to MG-1 to counter the torque of the ICE. Otherwise the Sun
>> gear
>> just spins and no torque is delivered to drive the car.
>>
>> Dick
>>
> Thanks for that explanation, I have been trying all day to figure out
> why the ICE behaved the way it did when the battery failed.
> Will the newer Prius fail in the same manner if the main battery is
> lost?
> Allen
>
Posted by Bill on October 20, 2006, 4:10 am
> Allen:
> Yes, this inherent in the design of the Power Split Device of the Hybrid
> Synergy Drive, and it works this way for all Prius models.
> It is very hard to explain in words just how this planetary gear train
> works, but it can be seen, with a really terrific description, at Graham
> Davies web site at: http://www.jantzen.nl/prius/Techniek/
> Click on the Power Split Device page and you can study his moving diagrams
> and descriptions for hours.
> Dick
That's just great Dick. We can only hope Toyota will re-design the device
so the ICE can propel the car if the main battery fails.
Posted by Allen on October 20, 2006, 1:32 pm
Bill wrote:
> > Allen:
> > Yes, this inherent in the design of the Power Split Device of the Hybrid
> > Synergy Drive, and it works this way for all Prius models.
> > It is very hard to explain in words just how this planetary gear train
> > works, but it can be seen, with a really terrific description, at Graham
> > Davies web site at: http://www.jantzen.nl/prius/Techniek/
> > Click on the Power Split Device page and you can study his moving diagrams
> > and descriptions for hours.
> >
> > Dick
> >
> That's just great Dick. We can only hope Toyota will re-design the device
> so the ICE can propel the car if the main battery fails.
Toyota places a lot of faith in the main battery. They have designed
software that they think will keep the battery working for the life of
the car. So designing safe/driveable failure modes for the loss of
main battery probably was not high on the engineers list.
However, the battery is constantly monitored and will generally show
signs of impending failure long before it actually fails. I just want
the car to give me a warning that something really bad is going to
happen in the next hour or so, so I will no be surprised when the car
dies on the expressway.
It is taking 3 days for the dealer to get a new battery in to repair my
car, If I had been on a long trip hundrends of miles from home this
would of been very bad. I would of liked a "HAL" like announcment on
the display that there is an 90% chance of total battery failure within
the next 72 hours.
> the main battery fails, is because the delivery of power to the ring gear of
> the Power-Split-Device (and to the wheels) is dependent on there being power
> delivered to MG-1 to counter the torque of the ICE. Otherwise the Sun gear
> just spins and no torque is delivered to drive the car.
> Dick