Specifications

Document No. DER05023 PREVENTIVE MAINTENANCE
Page 4 of 5 Effective Date 24 Apr 08
Drive Belts
The drive belts should be tensioned periodically and replaced if inspection reveals damage or
deterioration. To tension and/or replace the belts, proceed as follows:
WARNING! ALWAYS ALLOW ROTATING ASSEMBLY TO COAST TO A
COMPLETE STOP BEFORE REMOVING BELT GUARD.
1. Shut down, lock out, and tag out electric power to the centrifuge.
2. Remove belt guard.
3. Loosen four screws securing flexible coupling half (Figure 5023-2) to shaft of conveyor drive
motor, and slide coupling half toward motor until end of motor shaft is visible.
Figure 5023-2 Conveyor Flexible Coupling
4. Loosen bolts securing bowl drive motor to base, turn tensioning bolt to loosen belts, and
remove belts from bowl and motor sheaves by maneuvering out between conveyor drive
motor and conveyor shaft.
5. Install new belts onto bowl drive motor and bowl sheaves.
6. Turn tensioning bolt to apply tension to belt. Apply sufficient belt tension to permit a 1/2”
(13mm) deflection when pressed with a 17 lb (75 N) force at the midpoint of the belt (Figure
5023-3). Correct tension will prevent slippage without overloading bearings. After correct
tension is set, tighten motor base retaining bolts to secure motor.
7. Slide flexible coupling half back into engagement with coupling half on conveyor drive gearbox
shaft. Set gap between coupling halves in accordance with Rotex manual in Section 12. Install
and tighten screws to secure coupling half in accordance with Rotex manual.
8. Install and secure belt guard.