20
20
M R O
Q U I Z
Machinery & Equipment MRO
September 2021
TROUBLESHOOTING INDUSTRIAL CHAIN DRIVES Chain drives operate through tension engagement, where teeth on both the drive and driven sprockets engage with and pull the chain links.
T
here are two basic types of industrial chain drives. Roller chains contain pins that pivot inside bushings with a free turning roller surrounding each bushing to provide rolling contact with the sprocket teeth. This chain type is commonly used in power transmission systems for both horizontal and vertical applications. The distance between pin centers is referred to as the pitch. Extended pitch drive chain contain only half as many pitches and is lighter and less expensive than standard roller chain. Also called double pitch chains, these can be fitted with larger rollers
that act as wheels for use on conveyor systems. Many conveyor systems use chain drives that use polymeric or plastic rollers that are impregnated with self-lubricated materials. Does the maintenance group have a well-designed drive chain inspection schedule? Logic: A correctly sized and properly installed drive chain can be expected to provide at least 15,000 hours of service, provided regular inspections are carried out and potential problems dealt with immediately. In a 24/7 operation, it is recommended that at every shift change,
chain drives are visually inspected for adequate lubrication, obvious chain link or sprocket damage, unusual noise, evidence of vibration or improper alignment. At monthly intervals, the chain should be inspected for correct tension and any abnormal condition. If oil appears cloudy, dirty or darker than usual, it should be changed. Annual maintenance should include an inspection for cleanliness of components and removal of all dirt and foreign material from chain and sprockets. Inspect the chain for side plate wear, fatigue, elongation or corrosion. Inspect shaft and sprockets for proper alignment
Photo: © Aleksandr Kondratov / Adobe Stock
BY L. (TEX) LEUGNER
