I think the ounce of rubber applies. Planetary gear sets are largely self
aligning. Not only the angle of the gear but the radial position of the
planet gear. If you constrain them too much then you get high point contact
stress concentrations. You just have to keep the planet gears from
interfering with each other that's all.
Paul Lamar ...No rotor no motor.
Paul,
I don't think that the planets can have that rubber sleeve if the drive
is being taken from the planet carrier as it is in the 2.85:1 units. If
they are driving the ring gear maybe...
Bill
Well the Ford planet carrier is straddle mounted pins so the
load goes into both ends of the pin more or less equally and
thence into the planet carrier and thence into the prop shaft.
There is no doubt a self aligning spherical bearing such as the Timken
could
do a better job of equalizing the loads from the planet gear going
into the pin instead of needle rollers.
Here is small bearing that works the same way almost.
The smallest Timken is about one inch or 25 MM bore.
-- Paul Lamar ...No rotor no motor.
---------------------------
BTW to get the same theoretical load ratings we have now you would need
four narrow (1/4 inch) pinion gears and these spherical ball bearings
per pin
for a total of 24 bearings and pinion gears. We would have to scale it up
as a 1/4 inch pinion shaft is not going to hack it. Going fast cost
money. How fast do you want to go ? :)
No beating needle bearings for a compact design.
Paul Lamar ...No rotor no motor.
No arguement Paul,
Needles are hard to beat for strength at a given (small) diameter.
Reguarding the "speed costs money." "How fast do you want to go?"
Question, the answer is faster than the next guy and for less money!
Something to note for those new to needle bearings, a needle bearing
that is caged is usually a stronger bearing at high speeds than loose
needle bearing that has the same needle diameter. This isn't obvious but
usually true. Yamaha and Kawasaki both had specialty bearings made for
the small end of their 2 stroke connecting rods. Very pricy but the
bearings would hold up at 10k RPM on the road racers. Remember 2 cycles
are usually close to square bore/stroke ratios so they can have enough
port area to be effective. These engines were redlined at about 11K but
had no power above 10k. They used a special cage that was made of
unobtainium and silver plated to boot. Some of these might fit the
planets we use. I'll check into it. Paul do you remember the minor
diameter of the Ford 6 pinion carrier?
Bill Jepson
There are at least two different sizes. I don't have a six pinion
here but the old 4 pinion should be the same as the only thing they
changed was the material and the number of pinions. For the planet
set that is 2.17 and 3.17 it is 2.2 inches. The one used for 1.85 and
2.85 is larger I think. That one is 2.6 inches.
Here is an old dwg long before Ford thought of it :)
Paul Lamar ...No rotor no motor.
The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site.
http://www.rotaryeng.net
Copyright 1998-2006 All world wide rights reserved.
