Instruction manual

ÊMotor, Belt, and Pulley Replacement
Part numbers for belts, pulleys, and related components may be found on the Drive Chart and/or Drive Assem-
bly drawings for your machine. When ordering motors and motor parts from the Milnor
®
factory, provide the
machine model and serial number and the motor function (i.e., wash, drain, E1 (low extract), E2 (high extract) or
Autospot). Replacement rotors and bearings are available from Milnor
®
for some motors.
Whenever a motor, belt, or pulley is replaced, the corresponding pulleys must be precisely aligned when
reinstalled, the taper lock bushing properly tightened and the belt(s), properly tensioned. (See “V-BELT TENSION
ADJUSTMENTS” for tensioning procedure using a tension testing device available from the Milnor
®
factory.)
All pulleys (used for power transmission) on Milnor
®
Hydro-cushion
®
machines use taper lock bushings. This
feature greatly facilitates the removal and/or adjustment of these pulleys. Components of the taperlock bushing are
identified below.
ËTo Remove a Pulley
1. See FIGURE 2.
2. Remove the belts. Release belt tension by adjusting the
position of the component to which the pulley is attached
with the jack screws, until the belts easily slip off of the
sheave. Do not force belts off by using a pry bar or roll-
ing the sheave.
3. Loosen all three bushing cap screws.
4. Put two cap screws into the push-off holes in the bushing
flange and tighten alternately until the sheave has loosened
from the bushing (see FIGURE 2).
5. Remove sheave and bushing from the shaft.
ËTo Maximize Belt Life
1. Never mix new and used belts on a drive.
2. Never mix belts from more than one manufacturer.
3. Always replace with the right type of belt and observe V-belt matching limits.
4. Inspect belt grooves in sheaves and replace sheave for any of the following reasons:
a. Worn groove side walls. Walls should be straight (not curved inward) when viewed in cross section.
b. Chipped or broken side walls.
c. Shiny groove bottoms (indicating that belt is bottoming out).
ËTo Replace Pulleys and Belt(s)
1. Clean the tapered bore of the sheave, mating surface of the bushing, bore of the bushing, and the shaft until
free of any foreign substance (including paint).
NOTE: Do not use lubricants, “Locktite,” or other adhesives on these mating surfaces.
2. Assemble the key in the shaft keyway checking to ensure the key is a snug fit, neither too tight nor too loose.
3. Loosely assemble the sheave and bushing on the shaft in the approximate location for proper belt alignment,
allowing for take-up movement of the sheave. Make certain Grade 5 bolts, identified by the head marking
shown in FIGURE 3, were supplied.
4. Carefully tighten the cap screws alternately and progressively until the taper is seated (approximately the “In-
itial Torque” as shown in the “Taperlock Bushing Bolt Torque Specs” elsewhere herein). Rotate the sheave
to detect any wobble or runout (see FIGURE 2 next page).
5. Install the belts onto the sheaves (driving and driven) and with the slack of each belt on the same side, adjust
Sheave
(pully)
Shaft
Bushing cap screws
Key
Push-off holes
Head marking
(grade 5 bolts)
Taper lock
bushing
ÎFIGURE 2
(MSSMA407BE)
ÎTypical Taperlock Bushing
Construction
Adjust motor
position to
eliminate gap
Gap between
pulley and
straight edge
at point D
Point A
Point B
Check for Wobble
Straight edge placed against mating groove side of pulley
Point D
Point C
Sheave must be con-
centric with shaft
Check for Runout
Sheave
must
be at right
angle to
shaft
ÎFIGURE 3
(MSSMA407BE)
ÎTest for Pulley Alignment
(Straight edge must touch points A, B, C, and D)
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