Spencer Vacuum Cleaning Systems - Manual (Page 8)

8
V. Standard Overhung
Machine
Instructions for Disassembly and Reassembly (Multi-Stage)
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 the Notes on accompanying illustration.
General Configuration
The most common Spencer machines (standard overhung type
construction) have the impellers mounted directly on the
extended motor shaft and are available as either single-stage or
multi-stage units. The multi-stage units are provided with deflectors
to channel the air efficiently from one impeller to the next. The
single-stage units are equipped with one impeller mounted
between the end head and division head of the machine housing.
The motor bearings support the shaft and impeller assembly.
Besides the customary motor maintenance, no additional attention
is required by the unit.
Disassembly
1. Remove End Head Bolts (5) and End Head (6).
2. Mark the motor shaft and impeller (8) hub with an arbitrary 12
o’clock reference point. Remove the first stage impeller (8A)
and mark it for reference during reassembly.
3. Check axial position of each deflector (7) at four radial points
with reference to end of casing and record for reference
when reassembling unit.
4. Remove spacer (14A) holding rope packing (4) in place.
Mark spacer for reference during reassembly.
5. Remove rope packing (4) holding deflector in place. Remove
deflector (7A). Mark for reference during reassembly.
6. Proceed to remove remaining stages in the same way,
marking each component to insure proper reassembly.
Note: Division Head (3) cannot be removed.
7. Unbolt division head packing plate (2A) and slide packing
plate and packing (2) back on the shaft.
8. Remove motor mounting bolts and slide motor (1) back.
Reassembly
1. Place the division head packing plate (2A) and packing (2) on
the shaft. If for any reason the packing (2) is damaged,
replace it. Install the motor (1) in the casing in its original
position. Be sure that the shaft is centered in the casing.
Assemble the packing (2) and packing plate (2A) to the
division head.
2. Run the motor (1) to check for vibration. If excessive vibration
is present, check the shaft for runout.
3. Place the first impeller (8C) on the shaft up against the
division head (3). Mark the shaft approximately 1/8” out and
withdraw the impeller to this point. This will insure a clear-
ance of 1/8” behind the impeller. Tighten the hub securely.
4. Inspect the interstage packing (9), if applicable, on deflector
(7B) and replace if damaged.
5. Place deflector (7B) back tightly against the stops in the
casing. Install the rope packing (4) firmly into the groove,
using a suitable tool.
6. Install the next impeller (8B) on the shaft up against the
deflector (7B). Mark the shaft approximately 1/8” out and
withdraw the impeller to this point. Tighten the hub securely.
7. Install the spacer (14B) into the casing. Make sure spacer
and deflector (7B) are pressed back tightly and at a uniform
distance from the end of the casing at four points.
8. Proceed in a like manner with remaining impellers, spacers
and deflectors.
9. Reassemble the end head (6) to the casing using a new
endhead gasket (12).
Balancing
Each machine is fully tested before leaving the Spencer factory
to be sure vibrations, if any, are well within specifications for this
particular machine. However, rough handling during shipment
or improper disassembly/reassembly of a machine can upset its
balance and/or result in excess vibration.
If there is any vibration due to an unbalanced condition after
assembly, use the following procedure.
After running at operating speed and when at rest, mark position
of end impeller hub on shaft. Loosen bolts or screws holding
impeller on shaft. Rotate impeller 90˚ on shaft. Retighten bolts
or screws. Run machine again at operating speed, and check
vibration. Repeat this process until the best position is located
for the impeller on the shaft so that there is no vibration in the
machine.
Note: In the event of trouble, notify The Spencer Turbine
Company, Windsor, Connecticut, or the nearest Spencer repre-
sentative, describing in detail the nature of the difficulty before
attempting to disassemble the machine.