Spencer Vacuum Cleaning Systems - Manual (Page 12)

12
VII. Four-Bearing
Outboard Machine
Instructions for Disassembly and Reassembly
Warning: Be sure all electrical power is disconnected prior
to performing Vacuum Producer maintenance.
Caution: Parts must be reassembled in exactly the same
relative positions. Therefore, it is recommended that each
part be marked as it is removed from the machine to facilitate
later reassembly. It is especially important that the location
of each impeller, as well as its position on the shaft, be
marked.
When ordering replacement impellers and deflectors, refer
to Notes on accompanying illustrations.
General Configuration
In four-bearing units of the outboard type, the impellers are
mounted between two supporting bearings of the Vacuum
Producer. The equipment is driven by means of a flexible coupling,
and although most standard makes of couplings can be used, a
gear type is normally furnished unless otherwise specified.
Standard sleeve bearing or ball bearing motors with standard
shaft dimensions are included, and the entire assembly is typically
mounted as shown.
Caution: Most four-bearing outboard machines have a
duplex (tandem) bearing assembly. These bearings are
available only from Spencer as a custom-matched set of
two: one bearing for thrust and one bearing for radial load.
These bearings are not interchangeable with commercially
available bearings carrying the same part number; they
can only be used in matched sets as furnished by The
Spencer Turbine Company. For best results, follow instruc-
tions enclosed with each matched set of bearings.
Disassembly & Reassembly
1. Remove packing plate nuts from packing plate (32 and 20)
on each end of machine. Slide both packing plates and pack-
ing (32 and 20) on shaft away from heads. Remove all pack-
ing from packing box when applicable (38 & 39).
2. Remove snap ring and back off coupling sleeve. Check gap
between coupling hubs. See coupling manufacturers instruc-
tions for other than Sier Bath.
3. Measure distance “B” from outboard bearing bracket (19) to
outboard bearing cap (17). Remove bolts in thrust assembly
housing cap.
4. Remove lock nut (15) and washer from end of shaft, and
loosen bolt (21) binding housing in bracket.
5. Remove bracket bolts (19A). Using puller, remove complete
thrust assembly and bearings.
6. Remove bolts on end head, holding flat ring and end head to
casing. (Use a chain hoist if available to hold head while
removing bolts). After removal of end head, keep shaft
supported while removing internal parts.
7. Remove intake spiral (13) after marking position to insure
correct reassembly. See note (A).
8. Remove rope packing (10) and half deflector (26).
9. On other than keyed construction measure distance from
impeller hub to any step or shoulder on shaft, and mark for
reassembly. On stacked and keyed construction, remove
nuts and washers (24A) and shaft sleeves (24B). Remove
impeller (29) and its hub spacer, number or mark them for
replacement in their proper position. See note (B) following
paragraphs.
10. Check axial position of each deflector at 4 radial points with
reference to end of casing and record.
11. Remove spacer (27) holding rope packing in place. Number
or mark for replacement.
12. Remove rope packing holding deflector in place. Then pull
or work deflector (11) out of casing. Number or mark for
replacement.
13. Proceed to remove the remaining stages in the same way,
numbering or marking all impellers, spacers, deflectors,
etc., to insure proper replacement.
14. Check deflector stops for damage.
15. Reassemble in reverse order, replacing end head gasket
(22) and any worn packing (32, 10, 25, 20).
To Change the Inboard Bearing (Motor End of the Machine)
1. Remove snap ring and back off coupling sleeve.
2. Check gap on coupling hubs.
3. Loosen and remove motor bolts, and slide motor back.
4. Remove coupling hub from machine shaft.
5. Remove packing plate nuts from packing plate (32 and 20)
on each end of machine. Slide both the packing plates and
packing (32 and 20) on the shaft away from the heads.
Remove all packing from packing box where applicable.
6. Remove bolts on both caps (8 and 8A) on three-arm
bearing bracket (33).
7. Slide front cap off shaft, and push back cap away from
bracket.
8. Remove bolts holding inboard bracket in position while
supporting end of shaft.
9. Slide inboard bracket off bearing.
10. Remove locknut, washers, and bearing.
11. Replace bearing and parts in their proper order.
Realign coupling and check the hub before and after bolting
motor in place (Refer to page 4).
Notes:
(A) Upon reassembly, with all internal parts installed, the intake
spiral edge should project slightly beyond end of casing so that
end head will hold all stationary parts in position.
(B) On stacked and keyed impeller construction, the first nut
installed is tightened with a spanner wrench, then loosened one
full turn to allow for impeller hub expansion. The second nut is
brought up to the first nut with the lockwasher in between. Lock
nut in position with washer tabs.
Balancing
Each machine is fully tested before leaving the Spencer factory
to be sure vibration, if any, is within specifications for the partic-
ular machine. However, rough handling during shipment or
improper disassembly/reassembly of a machine can upset its
balance and result in excess vibrations.
When a machine is being disassembled for repairs, mark the
parts as they are removed. If this is done, no trouble should be
expected from vibration when they are re-assembled in the
same order.
However, if the impellers are being replaced or there is any
vibration due to an unbalanced condition after assembly, use
the following procedure:
If there is any vibration or unbalance, the coupling should be
checked first for misalignment. If realignment does not correct
imbalance, rotate coupling hubs or machine shaft and motor
shaft in 90˚ increments until minimal vibration is obtained.