Nexen PRD1100 966902 - Manual (Page 11)

FORM NO. L-21274-A-0113 11
Proper roller to tooth meshing can be verified by two
methods depending on which you find easier to interpret:
Option 1: Apply a slow drying machinists dye to the pinion
rollers and move the RPG system back and forth over a
short distance (about 1/2 meter). It is important the dye
remain wet so it transfers to the gear teeth and is not
depleted. Analyze the dye pattern transferred to the teeth.
If the meshing geometry is good the dye will be spread
evenly all the way across the tooth face over the middle
2/3 - 3/4 of the teeth with none at the top and bottom. If
this section is properly aligned clean off dye residue and
repeat as necessary to verify the RPG alignment over the
entire rotation as shown in Figure 12.
Option 2: Apply a small amount of high contrast grease
to each gear tooth face over 1/2 meter of circumference.
Operate the RPG system back and forth over this 1/2
meter of travel. If the meshing geometry is good the
grease will be completely wiped away all the way across
Good Alignment Poor Alignment
Contact Pattern Contact Pattern
Figure 12
the tooth face over the middle 2/3 - 3/4 of the teeth with
some remaining at the top and bottom. If this section is
properly aligned clean off grease with a solvent and repeat
as necessary to verify the RPG alignment over the entire
rotation as shown in Figure 12.
SYSTEM ALIGNMENT VERIFICATION
If the dye or grease contact pattern indicates a meshing
problem, diagnose the problem, correct it, and then repeat
the Applying Preload and System Alignment Verification
procedures.
Table 4
Screw
Tightening Torque
Nm [in-lb]
Preloader Screw
All Models - 1.7 [15] Max
Shoulder Screws (Mtg. Plate)
RPS-PRE-064 M8x1.25 40 [350]
RPS-PRE-090 M8x1.25 40 [350]
RPS-PRE-110 M8x1.25 40 [350]
RPS-PRE-140 M8x1.25 40 [350]
RPS-PRE-200 M12x1.75 120 [1060]
Gearhead Screws (Mtg. Plate)
RPS-PRE-064 M4x0.7 5.3 [47]
RPS-PRE-090 M5x0.8 10 [88]
RPS-PRE-110 M5x0.8 10 [88]
RPS-PRE-140 M6x1.0 17.5 [155]
RPS-PRE-200 M8x1.25 40 [354]
Preloader Mtg. Screws (2x)
All Models M6x1.0 17.5 [155]
3. Verify that the pinion rotational axis is as parallel as
possible to the gears rotational axis, and the gear
is centered between the pinion bearing flanges as
shown in Figure 1.
4. Rotate the preload adjustment screw clockwise to
separate the pinion from the gear. This will ensure
that clearance is initially present. Then seat the pinion
into contact by turning the preload adjustment screw
counterclockwise until a slight resistance is felt and
then back the screw off 1/8 of a turn. This step is
critical to prepare for preload settings.
5. Place a magnetic base dial indicator on the same part
of the machine as the motor and reducer, and locate
its probe on the OD of the pinion flange such that it
measures in the direction of preload travel.
6. Apply the preload of 0.010 - 0.015 mm [0.0004
- 0.0006 in] with the preload application screw(s)
and then tighten the preload lockdown bolts to
their recommended torques. See Table 4 for Nexen
Preloader System torque values. Typically the preload
will change slightly when the preloader lockdown bolts
are tightened. If tightening the preload bolts causes
the amount of preload to fall outside of specifications,
record how much it changed when tightening the
preloader lock down bolts then loosen the preloading
system and repeat the preloading procedure but
adjust the initial preload (more or less) by the recorded
preload deviation. This procedure will ensure that
when the preloader lockdown bolts are tightened the
amount of preload should fall within specifications.
7. With the pinion preloaded to specifications manually
rotate the gear by hand (if possible) checking for
smoothness and uniformity of resistance. If manually
applied motion is not possible, use the servo motor
to rotate the gear, with just enough torque output to
move it while looking and listening for resistance to
motion.