Important Notes; Additional Inspections; Post Inspection; Gaterotor Assembly Replacement (All Compressors Except Vsm 301-701 & Vsm 97-127 Compressors) - Emerson Vilter VSS Installation, Operation & Maintenance Manual

Section 5 • Maintenance/Service

Important Notes

1. Backlash cannot be checked if:
• The gaterotor is damaged in any way.
• The clearance between the gaterotor and the
shelf is too tight.
2. Make sure you check the backlash, not the float:
• The backlash is the clearance between the
gaterotor teeth width and the rotor groove.
• The float is the amount of play between the
gaterotor bushing and the damper pins.

Additional Inspections

In addition, visually inspect the main rotor and
gaterotors for signs of abnormal wear due to dirt or
other contaminants.
If some chipping is present on the edges of the
gaterotor, this will not influence the compres-
sor performance. If chipping is more than what´s
shown on Figure 5-39, take pictures and contact
Vilter Service Department.

Post Inspection

After all the inspections are complete, the gatero-
tor cover, suction tee, coupling center member and
coupling guard can be reinstalled and the unit can
be evacuated and leak checked before starting.
Figure 5-39. Chipped Edge of Gaterotor
5 – 42
VSS/VSM/VSH/VSSH • Installation, Operation and Maintenance Manual • Emerson • 35391SD
Gaterotor Assembly Replacement
(All Compressors Except VSM 301-701
and VSM 97-127 Compressors)
Table 5-14 lists the gaterotor tool sets needed to remove
and install gaterotor assemblies.

Table 5-14. Gaterotor Tool Kits

Model
VSM 97- VSM 127
VSM 71-VSM 401
VSM 501-701
VSS/VSSH 291-601
VSS/VSH 751-1301
VSS 1551-2101
VSS 2401-3001

Removal

1. Remove center member, see appropriate Drive
Coupling Replacement procedure.
All parts must be kept with their appropriate side
and not mixed when the compressor is reassembled.
2. Remove two upper bolts from side cover
3. Install guide studs in holes.
There will be some oil drainage when the cover is
removed.
4. Remove remaining bolts and side cover.
5. Turn main rotor so a driving edge of any one of the
main rotor grooves is even with the back of the
gaterotor support.
The gaterotor stabilizer is designed to hold the
gaterotor support in place and prevent damage
to the gaterotor blade as the thrust bearings and
housing is being removed.
6. Insert gaterotor stabilizer. The side rails are not
Tool Set VPN
N/A
N/A
A25205B
A25205B
A25205C
A25205E
A25205F
NOTE
NOTE
NOTE