Table of Contents
Advertisement
5.3 Adjusting Tip Clearances
1.
Place an identifying number on the leading
side of the first blade e.g .. #1'. This is
important - it is easy to miss a tip unless
every blade is marked as it is adjusted.
2.
Loosen the retaining screws holding the
wear tip on blade #1. You wilt need a ¼"
allen key.
3.
Rotate the blade until it is about 1" (25mm)
inside the airlock casing opposite the
flexible tip wiper. Note: Blades are angled
slightly on the shaft so one end will be
further inside the casing than the other.
4.
Place a feeler gauge (or shim) between the
tip and casing 4" (10 cm) from each end of
the blade tip (2 feelers or shims needed) -
use 0.008" (8 thousandths of an inch)
5.
Gently lever the blade upwards until it
contacts the feeler gauges or shims.
6.
Tighten tip screws ... CENTRE SCREW
FIRST!
7.
Rotate the airlock counter-clockwise for a
full revolution (viewed from driven end) and
listen for binding noise between the tip and
the casing. A light grinding noise is normal
and will disappear as tips seat fully during
first few hours of operation.
8.
Repeat the Tip Adjustment Steps for
Each Blade. Mark each blade with its
number (i.e. #2, #3 etc) as you work on it to
ensure that none are missed.
9.
Adjust the Flexible Tip Wiper. Each tip
should contact the flexible tip wiper lightly
as the rotor turns. Replace if Wiper is worn
excessively or damaged .
• Check that Rotor turns
COUNTER-CLOCKWISE
after Connecting Power·
(viewed from driven end)
5.4 Out-Of-Round Casing Wear
An airlock that has excessive out-of-round
wear in casing will operate poorly. Airlocks
wear rate and out-of-round wear increase
greatly if the rotor is operated in the
incorrect direction. It MUST rotate counter-
clockwise when viewed from the shaft
(driven) end.
To check for excessive out-of-round wear in
the casing:
1. Adjust airlock tip clearances as per 5.3
2. Any clearances above .020" will reduce
performance.
3.
If tips need setting at higher than .11"
performance may be unacceptable
especially in light feeds. The out-of
round casing will need machining.
Airlocks must be re-machined by tool
shops with experience in this type of work.
Inaccurate alignment of end-plates and
casing is the most common error in a re-
machining job. They MUST align on the
same shaft centre-line. End-plates would
normally be dowelled to the casing after
machining to ensure correct alignment.
10
Advertisement
Table of Contents
