Alan,
Be sure to note Matco MFGs. website or my website on the proper way to
torque wheel bearings. The inner race must not move (rubber seal does not
rotate).
The nose wheel is a Matco unit also. The easy method of fixing the bearing
is by axle nut torque with the inner race locked to a flange on the inner
race. Tough to do on a nose wheel.
The old style NG06 axle (the smooth one with the dumb spacers), is a piece
of cake to maintain.
To remove the axle from the wheel on a used aircraft:
No torches.
Put the wheel flat on a large vice or a couple of thick timbers across the
wheel rim with the axle in the slot. Whack the end of the axle with a dead
blow or wood mallet. The bearing will pop right off with no damage. Flip
the wheel over and hit the other side of the axle. Both bearings are free.
(I only drive one side off and clean and pack the other on the axle).
Take a single edge razor or a razor knife, and take off the Loctite, clean
with a bit of acetone. Pack the bearings as usual. Clean the inner race of
any grease.
Do not use a lot of Loctite 638, a small drop or two is sufficient on the
bearing.
Slide on the other parts and slip into the yoke. In 15 minutes, go fly.
(Realistically, do the mains next.)
So it takes 6 minutes to do a nose axle grease job.
If you desire, buy the new axle with a nut on the Europa website. Matco
basically copied this design. See their website. Europa Loctite's on the
nut, and Matco came up with a new nut with a set screw in it. The axle now
has a slot. This was incorporated on the RV10. Loctite works.
Split wheels on aircraft (not ultralights) are split rims due to structural
concerns. Our main wheels only hold 650 pounds of aircraft weight, right.
WRONG, these wheels are designed for impact loads exceeding 4000 lbs of
force. Hence the 1.25" bearings (stronger), the centrifugally cast wheels
with the extra meat on the bearing race areas are needed. Bearings must be
rigidly in contact with their races and not rotating on the axle to meet the
structural load conditions. No bearing wiggle or slop. In fact, properly
seated, the wheel is a bit draggy.
Split wheels are a pain, but strong for their weight. I highly recommend my
clients put a piece of one inch heavy paper ring on the inside of one of the
wheels to prevent pinching the tube when assembling the wheel. If my guys
in the shop pinch a tube not using the paper safety ring, they pay for it.
Hope this sheds some light on the wheels.
Regards,
Bud Yerly
-----Original Message-----
From: Alan Carter
Sent: Sunday, March 22, 2015 7:51 AM
Subject: Europa-List: Re: Nose Wheel Bearing
Thanks Guys,
As you may know i am not a builder, but have down loaded a diagram of the
nose wheel , I see it has tapered roller bearings, which as far as i can
see the outer shell is bonded to the actual 2 parts of the wheel hub,
The wheel component is made in two parts and bolted together to make the
wheel complete, and if necessary unbolted to split the wheel in order to
repair a tyre puncher,
If the outer shell of the bearing is bonded to these two wheel hubs you can
not split the wheel apart the bonded bearing shell holds it togeter ,, well
not quit true you need heat, and i don,t fly with a blow torch in the back
of the plane.
I am not an engineer either, but why could there not be two smaller width
bearing used, each being bonded to its respected half wheel hub, so each
contains its own bearing and can be split apart easily .
Also bonding why bond, surly there are bearing with( don,t know what you
call it ) but say 3 projected lug locators so as to drop into a located hub
housing to prevent the outer shell from turning.
I like 5 minute bearing changes,
Please comment and inform me of the why not,s . Basically I would just like
some explanation to satisfy my own mind, I may tend to see thing to simple.
I believe a mod has already been worked out for the nose wheel which I am
also looking into, and may have done,
Alan
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