Wilo 4/5 TYPE 17, Инструкция по установке и эксплуатации

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Installation and operating instructions WILO Mather and Platt – Sump Pumps 28
10.4 Examination of Internal Components
With the disassembled rotating element, the internal components
and clearances should be checked.
10.4.1 Casing neck ring
Use an internal micrometer to measure the bore of casing ring,
taking measurements at intervals around the circumference to
check for uneven wear. A comparison between this dimension and
that of the impeller neck will indicate the amount of diametrical
clearance between the casing neck ring and the impeller neck. If
this clearance is 150% or more than the original design clearance,
or if the deterioration in hydraulic performances has been such that
no further deterioration can be tolerated during the next operation
period, the neck ring should be replaced.
Refer Pump Technical
Data for Details (Pg. No. 24)
The impeller-wearing ring to casing neck ring clearance must be
restored to the original design value by fitting small in-bore neck
rings, bored out to suit the diameter of the impeller.
10.4.2 Shaft Sleeves
The shaft sleeve should be examined to see if it is grooved or
generally worn. The outside diameter of the sleeve should be
measured, and a comparison made with the bore of the stuffing box
bush through which the sleeve passes. The amount of clearance
between the two can thus be checked to determine whether or not
it is within acceptable limits.
10.4.3 Impeller
Inspect the impeller as follows:
•
Inspect the impeller for mechanical damage, corrosive pitting,
cavitation etc. If damage is extensive, the impeller may need
replacement.
•
Examine around the eye at neck portion for grooving; slight
grooving is acceptable, but deep or profuse grooving must be
remedied by machining the impeller and fitting small-in-bore neck
ring.
To check wear around eye, use precision tools such as outside
micrometer to accurately measure outside diameter of impeller.
When this diameter is subtracted from internal diameter of neck
ring, which is measured in sequence 2.1, clearance obtained should
not be more than 150% of maximum designed clearance.
Refer
Pump Technical Data for Details (Pg. No. 24)
10.4.4 Shaft & keys
Shaft should be checked for the trueness, or any other mechanical
damage and corrosion. If the shaft is not true within 0.1 mm TIR
(Total Indicated Reading), it should be replaced / repaired. Examine
the shaft keys and keyways. Remove damaged or worn out keys.
10.4.5 Bearings
•
Visually inspect the bearings. The balls, the inner and outer tracks
must all be free from chipping, cracks, abrasion or discoloration.
•
Inspect the bore for any sign of damage. The burrs of any scratches
caused during bearing withdrawal should be carefully removed by
the hand application of a fine oil stone, the treatment being
confined to the minimum possible area.
•
Visually inspect the outside diameter for signs of fretting; any stains
may be carefully polished off, but abrasion must be kept to the
absolute minimum that is required, followed by cleaning.
•
Check that bearing rotates freely and smoothly. If there is any doubt
regarding the serviceability of the bearing it should be renewed.
10.4.6 Bearing Cartridge
•
Visually inspect the bore for any signs of fretting; any stains
may be carefully polished off, but abrasion must be kept to
the absolute minimum that is required, followed by cleaning.
•
Where fretting has occurred, bearing and cartridge should be
cleaned, and trial assembled. Bearing should be transitional
fit.
10.5 Reassembling the Pump
Follow the procedure given below in case of pumps to be
erected for the first time or pumps to be assembled after
dismantling for overhauling. Clean all the parts thoroughly
with kerosene, petrol to remove dust, dirt etc. Check the
sleeves bore and shaft outside diameter which is free from
burs and scratches. Deburr if required. Replace the parts with
a new one if found damaged. Use new gaskets and O rings at
the time of reassembling.
a) Fit the bearing bush (pump end) in the back cover. Mount
the support pipe (Bottom) on the back cover. Fix the screws
between support pipe and back cover.
b) Insert the shaft sleeve on pump shaft (Impeller end) with
key and insert the intermediate sleeve at the other end
(muff coupling) and tighten the grub screw with the shaft.
Insert the pump shaft through the back cover.
c) Place the key in position and mount the Impeller. Place
the lock washer, take care that the pinch projection in
washer should lock with the hole provided in the Impeller
face and screw the Impeller nut. Tighten the Impeller nut
along with lock washer and fold it along with the impeller
nut for securing the nut from unscrew.
d) Insert the assembly so far completed into the pump
casing with O ring (in between back cover and casing) in
proper position. Tighten the hex. nuts on pump casing studs
diametrically opposite evenly.
e) Fit the bearing bush (Intermediate) in the Intermediate
bearing bracket and mount it on the support pipe (bottom)
top face.
This completes the casing assembly. At this stage the
pump shaft will be projected above the Intermediate
bearing assembly.
f) Insert the intermediate shaft sleeves on the Intermediate
shaft both ends and tighten the grub screw.
g) Connect the Intermediate shaft to the pump shaft by
means of muff coupling. The muff coupling sleeve first be
slide on the intermediate shaft. Put the keys on both ends
of the shafts and bring both the shaft ends close together
in line. With slight adjustments of shaft fit the split collars
on the both ends of the shafts and slide the muff coupling
on the pump shaft till it rests on the shaft step. Ensure
proper fitting of the muff coupling with both the shafts and
tight the grub screws provided on the muff coupling.
h) Lower the intermediate support pipe and connect it to
the bottom support pipe. Tighten diametrically opposite
bolts evenly.
i) Repeat the same procedure till top shaft. (Ref. fig. 15;
Page No. 12)