Rans S-7S COURIER, Текстовое руководство

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09/01/2014
01A-02
MAIN GEAR WHEEL/BRAKE INSTALLATION
9. Become familiar with the Main Gear Wheel/Brake Installation Parts Drawings
and collect the parts shown in the drawings.
10. Bolt caliper mount, and axle to the gear leg assembly as per parts drawing.
Assemble the wheel and brake kit as per parts manual and manufacturer’s
instructions. With the aircraft in a level attitude, the brake assembly will be
orientated to the aft and down.
CAUTION: Be sure to safety wire the bolts
holding the brake disk. The tire pressure should be approximately 20-25 psi. To
install the wheel assembly, the outer brake pad removes via the 1/4" retainer
bolts.
11. Clean and pack the tapered wheel bearings. The tapered roller bearings are oiled
from the factory for rust prevention, but not greased. The roller bearings should
be cleaned, dried, and then packed with suitable grease. Packing grease without
first removing the oil will dilute the wheel grease, causing it to run out past the
seal and not lubricate properly.
12. Slip the bearings and wheel / tire assembly back onto the axle. Install the washer
and castle nut. Tighten the castle nut to manufactures specifications or bearing
failure may result. Secure with the large cotter pin.
IMPORTANT INFORMATION:
MATCO Mfg wheels using tapered roller bearings are equipped with Timken bearings
utilizing integrated grease seals on the bearing cone to ensure the longest possible life.
The torqueing procedure for bearings with these type seals is different than for tapered
roller bearings without them. A common torqueing technique for bearings
without
integrated seals is to tighten the axle nut until the wheel stops spinning freely and then
back off to the nearest locking feature. THIS TECHNIQUE WILL NOT WORK ON A
BEARING WITH AN INTEGRATED SEAL. The reason for a different torqueing
technique is that the grease seal produces some drag and makes the wheel feel
somewhat stiff when rotated. Reducing the axle nut torque until the wheel spins freely
will allow the grease seal and the bearing cone to improperly rotate with the wheel (the
cone must not rotate relative to the axle). The higher rolling drag is completely normal for
this bearing and allows for longer bearing life since the seal will keep most contaminants
out. Timken specification state, for example, that the two 1.25 inch tapered roller bearing
used on the WE51 will produce 18-26 inch pounds of torque (drag) when properly
installed. A light coating of grease on the seal will help reduce the drag on initial
installation. The drag will also reduce after the bearings have been installed and the seal
relaxes in the bore. It is important that the axle nut torque be sufficient to keep the seal
from rotating with the wheel. With the bearings cleaned, dried, greased, and inserted in
the wheel, the axle nut should be tightened until all play is out of the assembly. Rotate
the wheel back and forth while tightening the nut to help seat the bearings. When all play
is out of the assembly, and the wheel rotates freely, tighten to the next castle slot and
insert the cotter pin. The rubber seal on the tapered roller bearing will remain stationary
while the wheel rotates around it. If the seal is spinning on the axle, the nut should be
tightened further until the seal stops spinning with the wheel.