CAMCORP HVP with Roots Blower - Manual (Page 58)

11 For your nearest ROOTS office contact information, please consult the last page of this document.
Inspection & Maintenance: Universal RAI ® series blowers
A good program of consistent inspection and maintenance is
the most reliable method of minimizing repairs to a blower. A
simple record of services and dates will help keep this work
on a regular schedule. Basic service needs are:
• Lubrication
• Checking for hot spots
• Checking for increases or changes in vibration and noise
• Recording of operating pressures and temperatures
Above all, a blower must be operated within its specified rat-
ing limits, to obtain satisfactory service life.
A newly installed blower should be checked often during the
first month of full-time operation. Attention there after may
be less frequent assuming satisfactory performance.
Lubrication is normally the most important consideration and
weekly checks of lubricant levels in the gearbox and bearing
reservoirs should be customary. Complete oil change sched-
ules are discussed under LUBRICATION.
Driver lubrication practices should be in accordance with the
manufacturer’s instructions. If direct connected to the blower
through a lubricated type coupling, the coupling should be
checked and greased each time blower oil is changed. This
will help reduce wear and prevent unnecessary vibration. In a
belted drive system, check belt tension periodically and
inspect for frayed or cracked belts.
In a new, and properly installed, unit there is no contact
between the two impellers, or between the impellers and
cylinder or headplates. Wear is confined to the bearings
(which support and locate the shafts) the oil seals, and the
timing gears. All are lubricated and wear should be minimal
if clean oil of the correct grade is always used. Seals are sub-
ject to deterioration as well as wear, and may require replace-
ment at varying periods.
Shaft bearings are designed for optimum life under average
conditions with proper lubrication and are critical to the serv-
ice life of the blower. Gradual bearing wear may allow a shaft
position to change slightly, until rubbing develops between
impeller and casing. This will cause spot heating, which can
be detected by observing these surfaces. Sudden bearing
failure is usually more serious. Since the shaft and impeller
are no longer supported and properly located, extensive gen-
eral damage to the blower casing and gears is likely to occur.
Oil seals should be considered expendable items, to be
replaced whenever drainage from the headplate vent cavity
becomes excessive or when the blower is disassembled for
any reason. Some oil seal leakage may occur since an oil film
under the lip is required for proper operation. Periodically
leaked oil should be wiped off from surfaces. Minor seal
leakage should not be considered as indicating seal replace-
ment.
Timing gear wear, when correct lubrication is maintained,
should be negligible. Gear teeth are cut to provide the correct
amount of backlash, and gears correctly mounted on the
shafts will accommodate a normal amount of tooth wear
without permitting contact between lobes of the two
impellers. However, too high an oil level will cause churning
and excessive heating. This is indicated by unusually high
temperature at the bottom of the gear housing. Consequent
heating of the gears will result in loss of tooth-clearance ,
backlash and rapid wear of the gear teeth usually will devel-
op. Continuation of this tooth wear will eventually produce
impeller contacts (knocking), and from this point serious
damage will be unavoidable if blower operation is continued.
A similar situation can be produced suddenly by gear tooth
fracture, which is usually brought on by sustained overload-
ing or momentary shock loads.
Problems may also develop from causes other than internal
parts failure. Operating clearances within a blower are only a
few thousandths of an inch. This makes it possible for
impeller interference or casing rubs to result from shifts in
the blower mounting, or from changes in piping support. If
this type of trouble is experienced, and the blower is found
to be clean, try removing mounting strains. Loosen blower
mounting bolts and reset the leveling and drive alignment.
Then tighten mounting again, and make sure that all piping
meets blower connections accurately and squarely Foreign
materials in the blower will also cause trouble, which can
only be cured by disconnecting the piping and thoroughly
cleaning the blower interior.
A wide range of causes & solutions for operating troubles
are covered in the TROUBLE SHOOTING CHECKLIST. The
remedies suggested should be performed by qualified
mechanics with a good background. Major repairs generally
are to be considered beyond the scope of maintenance, and
should be referred to an authorized ROOTS distributor.
Warranty failures should not be repaired at all, unless specif-
ic approval has been obtained through ROOTS before start-
ing work. Unauthorized disassembly within the warranty peri-
od may void the warranty.