V-Belt Tensioning and Pulley Alignment Guidelines

Warning:

These guidelines are general in nature and are not intended to be “instructions”.

It is the operators’ responsibility to educate themselves using reference material readily obtainable from “power transmission industry” sources.

It is very important that no one be allowed to apply the following guidelines without adequate experience in the field of V-Belt power transmission.

Most importantly, the operator must have knowledge and experience concerning the inherent danger involved when working on V-Belt power transmission equipment.

RMS Roller-Grinder

assumes no liability for the use of the following guidelines.

V-Belt Tensioning Guidelines:

Important:

Always make sure the rolls are fully closed before tensioning V-Belts. If belt tension is set with the rolls open, the belts will be too loose once the rolls are closed. This may result in belt failure or motor shaft/bearing failure.

V-Belts should be tensioned only as tight as required to prevent the belts from slipping. There are two signs of excessive belt slippage:

  1. Belts “squeal” for more than one second on start up.
  2. Belts are hot after only a short time of running.

(New belts will run warm during initial break-in, and may need to be re-tightened after a few hours running.)

Pulley Alignment Guidelines:

Important:

Make sure the rolls are fully closed before proceeding with the following instructions.

  1. Motor Pulley Alignment: Start by making sure the motor pulley is “in line” with the roll pulley(s). Place the straight edge against the face of the roll pulley and extend it across to just below or above the motor pulley. By slightly turning the roll pulley, with the straight edge held tightly against and rotating with the roll pulley, the straight edge should just clear the motor pulley, or be within 1/8” either in or out of the just clearing. If the motor or pulley is more than 1/8” in or out it should be repositioned on the motor shaft so that it is “in line”.

  2. Motor to Roll Parallel Alignment: First make sure the belts are tight but not too tight. Place the straight edge against the face of the motor pulley and extend it across to just below or above a roll pulley. By slightly turning the motor pulley, with the straight edge help tightly against and rotating with the motor pulley, the straight edge should just clear the roll pulley. Use the 2 motor adjusting rods in the back of the machine to get “in line”. If the belts are not tight enough yet, finish tightening the belts by turning BOTH rods clockwise the same amount.