Best BestReach BRR23030, Operation, Maintenance And Parts Manual, Page: 7 / 76

7
Maintenance Schedule, Motors
DC Motor Brush Maintenance
All motors used to power the conveying surfaces of the Best Reach Rigid Roller and Best
Flex conveyors are DC permanent magnet motors. These motors have a pair of
serviceable brushes that wear with use. Brush life is affected by the speed of the motor,
the loads being conveyed, the number of start-stop cycles and other factors. Therefore,
brush life will vary from application to application.
To ensure long motor life, brush inspection should be included in the normal maintenance
schedule of the conveyor. Brushes should be periodically removed, visually inspected and
measured.
The brushes are accessed by removing the two caps on the end of the motor opposite of
the gearbox (see photo 1 on page 8). With the cap removed, the brush may be removed
from its holder by pulling on the spring. Visually inspect the brushes for chips or grooves.
The shunt wire should not be frayed or broken. The brush should be replaced if it
measures 0.125 inches or less as shown in Figure 1. Possible armature damage could
result from running the brushes beyond this wear point.
When being installed, the brush should slide freely into the holder. The brass contact
connected to the top of the spring should be installed so its tabs are aligned with the motor
shaft (photo 2). One tab should be facing the rear of the motor and the other tab toward
the front. The tabs should go easily into the brush holder. Do not over tighten the plastic
cap that holds the brush in place.
Figure 1
(continued)