Aimco URW Series, Repair Manual

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October 2006
- 10 -
Disassembly and Reassembly of the Air Motor
(cont.)
4. Air Motor Plates: Inspect Plates for grooving. Light marks can be lapped out using a figure-eight motion
with 220 grit sandpaper on a Lap Plate. If heavy grooving is noted, replace.
5. Rotor: Inspect Rotor for sharp edges in Blade Slots and pitting and grooving on Plate Surface. Light marks
can be stoned with a medium oil stone. If deep markings exist, replace.
6.
O-Ring:
Inspect the O-rings for splitting or chipping; replace if necessary.
Reassembly
1. For the URW-6:
a. Remove the Casing from the Handle Casing.
b. Grease all Bearings. Place the Rear Plate on the rear of the Rotor and press the Rear Bearing onto the
Rotor. Note: There should be a slight amount of drag between the Rear Plate and the Rotor.
c. Lightly coat the Blades with air motor oil and install them in the Rotor flat-side out.
d. Place the Cylinder down over the Rotor making sure to line up the air port holes in the Rear Plate with
the holes in the Cylinder.
e. Install the Front Plate onto the Rotor and press the Front Bearing over the Rotor and into the Front Plate.
Note: The Cylinder should be tight between the Front and Rear Plate and the Rotor should turn freely.
f. Install the alignment Pin through the Rear Plate, Cylinder, and into the Front Plate.
g. Install the Air Motor into the Handle lining up the hole in the Handle with the alignment Pin in the Air
Motor.
2. For the URW-8N & 9N:
a. Grease all Bearings. Place the Rear Plate on the rear of the Rotor and press the Rear Bearing onto the
Rotor. Note: There should be a slight amount of drag between the Rear Plate and the Rotor.
b. Lightly coat the Blades with air motor oil and install them in the Rotor flat-side out.
c. Place the Cylinder down over the Rotor making sure to line up the air port holes and Roll Pin in the
Cylinder with the holes in the Rear Plate.
d. Install the Front Plate onto the Rotor aligning the Roll Pin in the Cylinder and press the Front Bearing
over the Rotor and into the Front Plate. Note: The Cylinder should be tight between the Front and Rear
Plate and the Rotor should turn freely.
e. Install the O-ring, Rear Plate Spacer, and Snap Ring into the Rear Plate.
f. Install the Air Motor into the Casing and install the Handle.
3. For the URW-8:
a. Grease all Bearings. Place the Rear Plate on the rear of the Rotor and press the Rear Bearing onto the
Rotor. Note: There should be a slight amount of drag between the Rear Plate and the Rotor.
b. Lightly coat the Blades with air motor oil and install them in the Rotor flat-side out.
c. Place the Cylinder down over the Rotor making sure to line up the air port holes and Roll Pin in the
Cylinder with the holes in the Rear Plate.