Page 339 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

Installation and Maintenance of VBelt Drives 319

Check Safe Speed Limits

Safe speed limits for sheaves manufactured by reputable companies
have been established by a rigorous burst testing program. The limit for
cast iron sheaves has been established at 6,500 fpm; the maximum speed in
rpm corresponding to 6,500 fpm is either cast or stamped on each sheave, as
shown in Figure 7-7.
Before installing the drive, this safe speed limit should be checked
against the speed of the shaft on which it is being installed. Operating
sheaves above recommended speeds could result in serious damage to
equipment and/or serious personal injury.

Typical Sheave and Bushing Installation Instruction

Tapered bushings are widely used, and have exceptional holding power
that eliminates wobble. Standard and reverse mounting features provide
greater adaptability. Quality bushings can be used interchangeably in
many of a given vendor’s products as well as those of other manufactur-
ers.
Before installation, you should thoroughly inspect the bore of the mat-
ing part and the tapered surface of the bushing. Any paint, dirt, oil, or
grease must be removed.
Assemble bushing into mating part in either the Standard or Reverse posi-
tions, as illustrated in Figure 7-8. (Since either the standard or the reverse
mounting assembly can be rotated so that the bushing flange is toward or
away from the motor, four ways of mounting are obtainable.)

Figure 7-7. Safe speed is cast into the arm of quality sheaves.