Belt Drive systems are a part of most industrial processes and can be critical to production. With the current signature capability of electric motor test equipment, belt drive problems can easily be identified. Belt drive systems exhibit similar indications for the following list of belt drive problems:
- Worn Belts
- Loose Belts
- Excessive Belt Tension
- Dished Belt
- Bad Belt Seam
- Mismatched Belts
- Eccentric Drive or Driven Sheave
- Misaligned Sheaves
Belt problems all share the same pulleys, pulley pitch diameter and belt length, so any problem with the drive system will result in a fault frequency related to those values.
For calculating belt frequencies use the formula below. Frequency = RPM/60 (or line frequency)
RPM WILL ALWAYS BE LESS THAN EITHER PULLEY RPM
Normally generates 3-4 multiples of belt
Often the 2x belt frequency is dominant
Loose cog belt show at number of cogs times RPM
When belt frequencies are present, the best resolution is to check belt tension and alignment of the sheaves. After alignment is completed and belt frequencies are still present, the problem is one of three things:
- defective belt
- eccentric driver sheave
- eccentric driven sheave
As part of a routine maintenance monitoring program, belt problems can be trended and identified as problems start developing. Use of infrared and vibration can also assist with the identification and correlation of data.