Overhead power conveyors greatly improve efficiency and safety in factories, warehouses, distribution centers, public utility plants, and other facilities, but only if they’re up and running. Downtime for your power conveyor can be costly and cause your facility to fall behind on important operations. Proper maintenance of your overhead chain conveyor will ensure this invaluable piece of equipment keeps providing a return on your investment for the long haul.
The lifespan of a conveyor chain is impacted by four factors, including:
- The weight of the load carried by the power conveyor
- The elevations and curves in the power conveyor itself
- The environment in which the chain operates. Extremes of temperature or exposure to corrosive substances may shorten the life of a conveyor chain.
- Maintenance and care
Facilities managers can address these factors to some degree. An efficient power conveyor system design is important to minimize the number of elevations and curves reducing chain wear. Next, if managers are involved in purchasing replacement conveyor chains, they need to make sure they are appropriate for carrying the loads they will be moving and for their operating environment. Steps to minimize chain exposure to corrosive substances and extremes of temperature can also mitigate environmental impacts to the chain.
Routine maintenance and care are the areas where facilities managers have the biggest opportunity to extend the life of their conveyor chain, as a carefully adhered-to schedule of inspection and repair can greatly extend the life of an overhead assembly line conveyor or power conveyor for other operations.
One of the greatest enemies of conveyor chain longevity is wear. System conveyor chain is in constant use in many manufacturing facilities, and the physical impact of metal on metal or metal on other surfaces causes the chain to deteriorate over time. On a conveyor chain, wear typically occurs between the chain pin, the link, and the drive.
Over time, wear can cause a chain to elongate. Many experts suggest that chains be replaced when they reach 1.5 to 2 percent elongation.
Chain elongation that is not monitored can create a multitude of operation malfunctions. Slack from elongation that is not removed can cause chain pulsation, which is the acceleration and coasting of the chain instead of smooth, uniform movement.
A more serious problem caused by chain slack is when the slack backs up into the drive unit. This will cause failure at the expensive drive unit, with possible damage to the conveyor chain itself. This can and will result in an accelerated rate of system wear and failure.
Regular lubrication and other maintenance can greatly reduce wear and help facilities managers get years of life from their conveyor chains.
Why Lubrication Is Vital
Lubrication creates a slippery film on the chain and any other components that may damage the chain. This film mitigates the impact of metal on metal contact that occurs when the device is in operation, reducing friction and wear. Proper lubrication also helps chains and chain components to resist corrosion, as it creates a barrier preventing moisture. Lubrication also helps to reduce the noise made when power conveyor systems are in operation.
Graphite-based lubricants tend to build up excessive deposits of foreign matter unless the chain is thoroughly cleaned at regular intervals. Proper lubricant should be recommended by a qualified lubricating engineer who has made a study of the processing machinery and atmospheric conditions to which the power conveyor system will be subjected.
Most overhead conveyor chains are sold pre-lubricated, providing them with protection when they begin to use in a facility. In some environments, it is not possible to lubricate chains, as the lubricant may be a fire or explosion risk. In these environments, regular, thorough cleaning of the chain will help increase its longevity.
The convenience of an automatic timer-controlled lubricator takes the guesswork out of lubrication. These machines are designed to precisely lubricate the critical bearing points of the conveyor chain. Nozzles dispense lubricant on the vertical and lateral wheel bearings, vertical link pin, and roller. Facility managers can set this style of lubricator to their schedule of operation from as little as 20 minutes or more to over 100 hours of powered conveyor operation.
A Schedule of Maintenance
Before you plan your schedule, consider this: Are maintenance hours limited? Do shift requirements or lack of personnel translate to a small window of opportunity for conveyor maintenance?
The following is a basic schedule of maintenance that facilities using conveyor systems may follow to help keep these systems in good repair. Further maintenance tasks may be recommended by your conveyor manufacturer.
- Create a chain maintenance log (similar to a preventive maintenance log) and follow it diligently.
- On a monthly basis, inspect the conveyor chain and confirm proper lubrication recommended by the lubricator manufacturer; check and adjust the conveyor take-up. This can be aided by having multiple chain inspection sections in the overhead conveyor track that are removable to closely inspect the chain.
- On a quarterly basis, check the conveyor chain for proper lubrication, wear, and elongation. Check track sections and curves for wear. Remove chain sections if necessary and/or adjust take-up.
In most companies, it is unlikely that all maintenance tasks and log-keeping will fall to a single individual. For this reason, it is important to make sure that all employees that are authorized to perform maintenance are properly trained. In addition to training employees to perform the maintenance tasks required, make sure that employees know how the logbook works and what information is required. An archive of information is only as valuable as the data provided; if key information is missing, it could have an effect on future maintenance.
You may also want to consider implementing an internal audit program, if possible. At regular intervals, check the maintenance logs for inconsistencies, missing information, and/or other concerning trends. You should also check the conveyor’s function to determine whether it is behaving appropriately (certain difficulties could be clues that some maintenance tasks have been ignored). Any glaring omissions from the log or conveyor chain problems due to missed maintenance should be brought up with the appropriate staff.
Read the Manual
To get a better idea of the maintenance tasks you’ll need to perform for your conveyor system, take the time to familiarize facilities managers with the manuals for these devices. Manufacturers of power conveyor systems take great care to list what maintenance is needed and when it should be performed. Richards-Wilcox has been providing efficient, durable assembly line conveyors to clients for more than a century.
Richards-Wilcox assembly conveyor systems’ chains are built to offer optimal efficiency and can provide 33 percent more throughput than other overhead chain conveyors available. With proper maintenance and care, Richards-Wilcox conveyor systems’ chains will return their installation and maintenance costs many times over on enhanced capacity, speed, and safety for facilities that incorporate them into their operations.