Scroll Medical & Laboratory Compressed Air Systems
Powerex
•
150 Production Drive
•
Harrison, OH 45030
•
USA
P 1.888.769.7979
•
F 513.367.3125
•
www.powerexinc.com
IN907800AV
•
08/2018
Page 30 of 40
The figure below shows the baseplate pulled out giving access for
pump maintenance. The pump may be removed if necessary, or the
motor may be unbolted and removed as well. Removing the motor or
the pump will require the belt guard to be removed first.
Slide Out
After the required work is performed, reverse the steps used for
disassembly. Be sure to open the intake isolation valve before turning
the power on.
Belt Tension Checking and Adjustment
The Powerex scroll compressor system uses premium vee-belts to
transfer power from the motor to the pump. The precision machined
drive pulley and pump sheave are aligned and tension is set during
initial construction to achieve optimum belt life. The belt construction
is referred to as raw edge belts, and rubber dust from the edge of the
belt may be deposited near the belt guard. This is normal and not a
cause for concern. The rate of dust shedding will diminish as the belts
break in to their long term optimum tension.
The most obvious sign that belts need attention is squeak or chirp
that is heard at start up when the motor is applying higher than normal
torque to the pump. The belt guard has a slot in the top surface so
a spring scale type tension gauge can be used without removing it.
A value of 20 pounds tension can be used as the minimum before
tightening the belt. (Deflection force of 3.75 pounds at 0.2 inches)
The motor slide base is provided to facilitate tensioning. Loosen
the clamping bolts on the side of the slide base underneath the back
of the motor and the bolts just behind the belt guard just enough to
allow sliding to occur. THE tension bolt can be used to pull the base
and motor away from the pump. Tighten the clamp bolts when the
desired tension is achieved.
For retightening of an existing belt set, use 30 to 35 in-lbf torque on
the tension bolt.
When installing new belts use 45 to 50 in-lbf torque. Note: if a belt
tension gauge is used, do not be concerned about the torque value.