Dresser Roots DVJ WHISPAIR, Installation Operation & Maintenance

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  Dresser Roots

Maintenance/Replacements

A good program of inspection and maintenance servicing, if 
followed consistently, is the most reliable means of prevent-
ing costly repairs to a blower. A simple record of procedures 
and dates will help maintain this work on a regular schedule. 
Basic requirements are lubrication and cleaning, along with 
periodic checking for increased vibration and hot spots on 
the cylinder. Inlet and discharge pressures and temperatures 
should be observed frequently, to minimize the chances for 
trouble resulting from blower ratings being exceeded. 

Above 

all, the unit must be operated within its specifications.

In a blower properly installed and operated, there is no 
moving contact between the two impellers, or between the 
impellers and cylinder or headplates. Wear is then confined 
to the timing gears, the bearings which support and locate 
the shafts, and shaft seals. All are lubricated, and wear 
should be normal if they are always supplied with clean, high 
grade lubricating oil. Shaft seals, weather lip type or rotating 
mechanical type, are subject to deterioration as well as wear. 
They may require replacement at varying periods. O-rings 
should be replaced at each disassembly. 
If trouble should occur during operation, and its cause cannot 
be readily determined, consult the TROUBLESHOOTING 
CHECKLIST. Remedies suggested there can usually be 
performed by qualified mechanics, using procedures detailed 
in this manual. Major repairs not covered here are considered 
beyond the scope of maintenance, and should be referred 
to the nearest Sales Office. See listing on the last page. 

Warranty failures

 should not be repaired at all, unless 

specific approval has been obtained through a Sales Office 
before starting the work. Unauthorized disassembly within the 
warranty period may void the warranty.
Where repairs involve parts replacement, it is recommended 
that Factory Parts be used to insure fit and suitability. Delay 
in making such repairs can be reduced by having spare parts 
on hand.
When ordering parts, please furnish all information from the 
blower nameplate.
Repairs or adjustments to blowers should be performed by 
personnel with a good background of general mechanical 
experience and the ability to follow the detailed instructions 
in this manual. Some operations involve extra care and a 
degree of precision work. This is especially true in timing 
impellers, and in handling bearings. Experience indicates 
that a high percentage of bearing failure is caused by dirt 
contamination before or during assembly. Therefore, clean 
the work area before starting disassembly, and protect new 
or reusable parts during progress of the work.
The following detailed work procedures cover repairs and 
adjustments that can normally be handled successfully at the 
installation site. Numbers shown in brackets ( ) correspond 
to Item Numbers used in the sectional assembly drawings 
and in Table 9. Refer to the drawing applying to the type unit 
being repaired while reading the instructions.

A - REMOVING GEARS WITH GEAR LOCKING 
ASSEMBLIES

1.  Drain oil at plug (67) near bottom of gearbox (3).
2.  Loosen cap screws (30) attaching gearbox to headplate
3.  Attach lifting device to support gearbox and remove 

capscrews. Move gearbox out of way.

4.  Match mark gears so that they can be returned to the 

same shafts in same position.

5.  Gradually release gear locking assembly capscrews 

evenly all round. Initially each screw should be released 
about a quarter of a turn only to prevent tilting and jam-
ming of collars. DO NOT REMOVE LOCKING SCREWS 
COMPLETELY OR THE COLLAR MAY SPRING OFF 
CAUSING INJURY. Just loosen the locking assembly, 
both collars should be loose on the tapered inner rings. 
To loosen the back collar, tapping on the locking screws 
may be necessary. To loosen the front collar, use of 
wedges between the collar and the gear web may be 
required

6.  Using two puller holes in the gear (see Table 6 for size) 

pull the gears off the shafts,

B - INSTALLING GEARS WITH GEAR LOCKING 
ASSEMBLIES

1.  Apply NEVERSEEZ paste on the gear locking device 

screw threads, under the screw heads, on the tapered 
rings, on the collar tapers, and on the gear hub outside 
diameters.

Figure 6 - Gear Locking Assembly

Table 6 - Puller Hole Sizes

Blower Size

Gear Puller Hole Size Carrier Puller Hole Size

1000

1/2/13

5/8/11

1200

3/4/10

5/8/11

1400, 1600

8-Jan

3/4/10

1800, 2000

1-1/4 - 7

8-Jan