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MOTOR DRIVEN PUMPS - INSTALLATION AND OPERATION
Pumps operating against a closed valve
can cause system failure, personal
injury and property damage
Hazardous pressure
can cause personal
injury or property
damage
V-BELT DRIVE
1. For installation of Blackmer V-belt units, first mount
the pump and the motor base to the unit base. Do not
fully tighten the motor mounting bolts until properly
installing and adjusting the belts as follows:
2. Wipe the cone surface of the pump QD hub (152A)
and the inside of the pump sheave hub with a clean
cloth moistened with a light grade of machine oil. This
will allow for a more uniform draw and prevent the
cone surfaces from “freezing” before being tightened.
3. With the pump shaft key (35) in place, align the key
seat and slide the QD hub (152A) on the shaft, flange
end first. Slide the large end of the sheave (152) bore
over the taper on the QD hub. Insert the three sheave
capscrews (152G) through the clearance holes in the
sheave, and start them into the tapped holes of the
QD hub (152A). Repeat this procedure to assemble
the motor QD hub (152E) and sheave (152D).
4. To install the belts (181), shorten the center distance
of the drive by moving the motor towards the pump,
until the belts can be put on the sheaves (152 &
152D) without forcing.
5. Align the sheaves so that the faces are parallel, then
snug up the sheave capscrews (152C & G).
6. Measure the span length as shown in Figure 8.
Figure 8 - V-Belt Adjustment
7. Adjust the motor base (183) and apply a specified
force (see Table 1) against the belt, at the center of
the span, so that the belt is deflected 1/64 inch (0.04
mm) for every inch (25.4 mm) of span. For example,
the deflection of a 20 inch (508 mm) span would be
20/64 or 5/16 inch (7.9 mm). The force required
should be within the range given in Table 1 for a
properly tensioned drive. A new set of belts should be
initially tensioned to the upper limit.
SMALL SHEAVE
OUTSIDE DIAMETER
BELT DEFLECTION
FORCE
Minimum Maximum
2.5” to 4.5”
(63 mm to 114 mm)
3.0 lbs
(1.4 kgs)
4.75 lbs
(2.2 kgs)
4.75” to 7.0”
(121 mm to 178 mm)
4.0 lbs
(1.8 kgs)
6.0 lbs
(7.7 kgs)
Table 1 - Deflection Force Per Belt
8. Check again to ensure the sheaves (152 & 152D) are
parallel, then tighten the sheave capscrews (152C &
152G), the motor mounting nuts (183B) and the
adjusting screw locknut (183B).
9. Assemble the belt guard (182) and the belt guard
brace (182A) to the unit base (32).
Operation without guards in place can
cause serious personal injury, major
property damage, or death.
Do not operate
without guard
in place
10. Check the belt tension after 24-48 hours of operating.
Recheck the tension periodically and tighten the belts
as required. DO NOT overtighten belts. Inspect belts
periodically for signs of excessive wear, and replace
as required.
V-BELT DISASSEMBLY
1. Remove the belt guard (182) and the guard base (182A).
Loosen the adjusting screw locknut (183B) on the motor
base (183) and the motor mounting nuts.
2. Ease the tension on the belts (181) by moving the motor
towards the pump to shorten the center distance of the
drive. Remove the belts by sliding them over the sheaves
(152 & 152D). DO NOT force the belts over the grooves.
3. To remove the sheave from the hub, first remove the three
sheave capscrews (152C or 152G). Then screw two of the
capscrews into the threaded holes in the sheave hub
(152A or E). If the cone grip is hard to break loose, tap the
end of the shaft or the QD hub with soft-faced mallet while
maintaining pressure on the screw.
4. The QD hub should slide smoothly off the shaft. If it is tight
on the shaft, gently pry it loose with a screwdriver or a
small wedge placed in the split part of the flange.
5.
Refer to Blackmer V-Belt Parts List and Instructions
for V-belt drive and guard part numbers.
