16
Gear Setting Procedure
Part numbers and references—refer to
Figures 6 and 16
.
The proper mounting of the gear set is essential to obtain long
life and smooth operation of the gears. The pinion cage position
adjustment is obtained by shims under the flange of the pinion cage.
Shims are placed under the top interstage bearing cap to adjust
ring gear position. The gear setting may require several attempts
before obtaining the proper backlash and tooth contact pattern.
The gear and pinion are match-marked when lapped and must be
assembled the same way. The ring gear has the end of two teeth
marked "X" and the pinion has one tooth so marked—the gears
should be engaged with the X-marked pinion tooth between those
marked on the ring gear. Match marks can be checked through
the inspection opening.
With the marked teeth of the gear engaged, check backlash with
dial indicator—see
Figure 16
. The indicator can be installed through
the inspection cover opening. Change shims under top interstage
bearing cap until backlash is between .007–.009" (.178–.228mm)
normal to ring gear tooth.
POINT OF NORMAL
BACKLASH MEASUREMENT
Figure 16
Gear Backlash Measurement
With gears adjusted for proper backlash, blue (Prussian Blue in
oil) the gear teeth. Drive the pinion by turning ring gear in both
directions for several revolutions. Observe the contact pattern on
both gears on both sides of the teeth. The contact pattern should
be as shown in
Figure 17
.
If correct tooth contact pattern is not obtained on first attempt,
refer to
Figure 17
—these illustrations show the two cases of
“out-of- position contact” in the extreme. One of the remedies
indicated will correct the out-of-position contact—compare the
tooth contact pattern with the illustrations in
Figure 17
and choose
the required remedy.
When proper tooth contact has been obtained, recheck the back-
lash at marked teeth. If it is within the desired range—.007–.009"
(.178–.228mm), check backlash with dial indicator at two additional
points 120° apart (with inspection cover removed), and as shown
in
Figure 16
. All backlash readings must be within the specified
range. If backlash is not within the limits, adjust ring gear height
with shims until it is, checking again as described.
The tooth contact pattern should again be checked to determine
if adjusting the backlash has produced any shift. If it has shifted,
move the pinion in the opposite direction the gear was moved
with respect to the cone center. If the gear mounting distance
is reduced, increase pinion setting distance, and vice versa, (see
Figure 12
) an amount proportional to the number of teeth in the
respective members. For example: on a 10 to 1 gear set, if the
ring gear was moved .010" (.25mm), the pinion should be moved
0.001" (.025mm). This would be necessary only if the contact
pattern had visually shifted due to movement of the ring gear
while adjusting backlash.
When setting a used set of gears, follow the method outlined
above. However, depending upon the amount of wear, it may be
necessary to set the gears up with slightly greater backlash in
order to obtain proper contact.
Proper tooth contact pattern is
the most important factor for correct installation.
Should a condition be encountered where correct contact cannot
be obtained as described in this manual, the Geareducer should
be returned to Marley in exchange for a factory reconditioned unit.
DIRECTION OF ROTATION
RING GEAR
ORIGINAL
PATTERN
AFTER
BREAK IN
*
*
*
*
CONVEX SIDE
ENTERING
CONCAVE SIDE
LEAVING
CONCAVE SIDE
CONVEX SIDE
OUT OF POSITION CONTACT
CAUSE: PINION TOO CLOSE TO
GEAR CENTER.
REMEDY: MOVE PINION OUT.
OUT OF POSITION CONTACT
CAUSE: PINION TOO FAR FROM
GEAR CENTER.
REMEDY: MOVE PINION IN.
CORRECT PINION AND RING GEAR TOOTH CONTACT PATTERNS
INCORRECT RING GEAR TOOTH CONTACT PATTERNS
Figure 17
Spiral Bevel Gear Tooth Pattern
field repair
Содержание Geareducer 3600
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