Belt Creep/Slip

Belt creep and slip — All belts

(except synchronous) creep, but creep

must be differentiated from slip. For

example, a V-belt under proper tension

creeps about 0.5% because of its

elasticity and the changes in cross

section and length taking place as a

section of the belt moves from the

tight side to the slack side of the drive

and back. That cyclical stressing, plus

the bending action of the belt as it

travels around the sheaves, causes

only a slight increase in belt temperature.

Most of that heat will be dissipated

by the sheaves so that they will

be only slightly warm if touched. (Of

course, the belt drive must be at rest

before an operator would dare touch

the sheaves.)

Slip, which is a movement greater

than the 0.5% creep, can create

enough heat to be very uncomfortable

if the sheaves are touched (again,

when the drive is stopped). Anotherway to check for slip is to touch the

belt (when it is stopped). If the belt is

uncomfortable to the touch (over 140F), it probably needs to be tightened.