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Nexen RPG25A-GE486T 966740 User Manual

Page 11

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11

FORM NO. L-21235-G-0413

ROLLER PINION INSTALLATION

Note: There are two pinion mounting styles, shaft

or flange mount. Refer to the following section that

applies to your situation. In either case it is critical to

minimize radial variance. It will effect pinion preload

and positional accuracy throughout the run.

Shaft Mounted Pinion Installation

NOTES:

• Refer to product drawings for shaft details.

• Refer to GENERAL DESIGN GUIDELINES and

Figures 1 and 2 for Roller Pinion mounting

requirements.

• The pinion should be mounted as close to a shaft

supporting bearing as possible to minimize shaft

deflection and obtain optimal performance.

• The shaft the pinion is mounted on must meet

minimum shaft insertion requirements as shown

in the RPS Selection Guide drawings for proper

pinion support and maximum torque transmission.

1. Clean the shaft the pinion will be mounted on and verify

that variance is less than ±0.013 mm [±0.0005 in] as
shown in Figure 11.

2. Inspect the shaft, pinion bore and the inner and outer

coupling halves to ensure they are clean and have no
defects.

3. Put oil that does not contain any pressure additives on

the shaft, the tapered part of the coupling and bolts as
shown in Figure 11. Do not lubricate the bore of the
pinion coupling or shaft where the coupling contacts
it or the torque transmission capacity of the coupling
will be reduced.

apply oil to these areas

<0.013 mm
[<0.0005 in]

<0.030 mm

[<0.001 in]

Figure 11

Figure 12 Coupling Installation Details

Align the outer coupling
slots between the inner
coupling slots

Coupling bolts

Outer Coupling Half

Inner Coupling Half

1

2

3

4

5

Threaded holes for
coupling removal

Tightening Order

4. Insert the outer coupling half into the roller pinion bore

until it bottoms in the roller pinon.

5. Insert the inner coupling half into the outer coupling

half (previously inserted into the pinion) while ensuring
that the inner and outer coupling half slots are not

aligned as shown in Figure 12. For RPS32 and
below you will also have to simultaneously ensure the
coupling bolt through holes align with the pinion bolt
holes. On RPS40 and larger the coupling bolts thread
into the other half of the coupling, not the pinion body
so misalignment is not possible. The threaded holes
in the outer coupling end are for coupling removal.

NOTE: Ensure that the slots in the two components

that make up the coupling are not aligned as shown

in Figure 12.

6. Insert the shaft into the pinion and coupling bore.

7. Insert the coupling fasteners into the through holes.

Only use the provided coupling fasteners.

8. Locate the pinion on the shaft and lightly tighten the

fasteners to take clearance out of all the coupling
parts but still allow the pinion to be moved axially on
the shaft. Position the pinion and coupling assembly
on the shaft so that the gap between rack face and
pinion roller bearing shoulders is even on both sides.
As the coupling fasteners are tightened the pinion
will be drawn slightly in the coupling direction so it is
recommended that the pinion and coupling assembly
be offset axially away from the coupling side 3 - 5 mm
[0.1 - 0.2 in] initially so when the coupling fasteners
are fully torqued the pinion ends up centered on the
rack.

9. Equally tighten the coupling fasteners with 25% of

the recommended tightening torque listed in Table
3. Start tightening at the top fastener and alternate
back and forth across the face in a star pattern as
shown in Figure 12. (The number of bolts will vary
with RPS size.) Repeat this procedure with 50% and
then full torque. An additional 1 or 2 repetitions at
full torque are recommended to ensure all fasteners
have reached their target torque values. Progressive
tightening of non-adjacent coupling fasteners is
important to prevent any misalignment of components
while installing the coupling.