Maintaining Modular Conveyor Systems In Flexible Manufacturing Operations

Maintenance schedules will vary according to the complexity of the conveyor system, but several tasks should be performed regularly to keep any system functioning properly.

Maintenance schedules will vary according to the complexity of the conveyor system, but several tasks should be performed regularly to keep any system functioning properly.

Regularly scheduled maintenance and attention to detail are crucial for ensuring the longevity and efficiency of these systems.

Pallet-based modular conveyors used in flexible manufacturing provide a wealth of benefits in just about any assembly operation. Suitable for applications ranging from small electronic parts assembly to large appliance manufacturing, automotive drivetrain and even medical-device assembly, these conveyors help improve production, achieve higher product quality and enhance manufacturing flexibility. And with different choices for conveying media, including belt, flat-top chain or roller chain, there are many configurations available, depending on the application.

While operations expects durability and long service from pallet-based conveyor systems, these can only be achieved through proper maintenance. Failure to properly maintain industrial conveyors can greatly reduce system life, and produce unexpected and costly downtime. Scheduling limited downtime for routine maintenance is always more desirable than dealing with an untimely, catastrophic problem.

One factor contributing to system performance and longevity is overall cleanliness. Conveyor systems should be wiped down weekly, and all grease and dirt should be removed from the conveyor and corresponding modules.

Scheduling maintenance

Maintenance schedules will vary according to system complexity. However, several tasks can—and should—be completed on a regular basis to ensure proper functionality of modular-assembly conveyor systems.

Check for missing chain caps that could inadvertently allow fasteners to lodge in the conveyor system.

Daily maintenance
On a daily basis, inspect and remove any small parts and debris that may accumulate on conveyor belts and chains. Examine belts and chains for visible wear, damage or separation. Replace any visibly damaged belts, chains or associated guides immediately.

Weekly maintenance
A key factor contributing to the performance and longevity of the conveyor system is overall cleanliness. Conveyor systems should be wiped down once a week. All grease and dirt should be removed from the conveyor and corresponding modules. Next, inspect the bottom of the pallets for debris that may become embedded. Fasteners from products being assembled have a nasty way of sticking where they’re not supposed to. Check T-bolts on pallet stop gates weekly, and tighten if loose. If a stop gate is skewed, it could indicate a loose fastener.

It’s also important to weekly inspect and, if necessary, lubricate flat-top or roller chains, sprockets and corresponding guides. Be sure certain chain tensioners are within the acceptable tension range, as chains will stretch over time. Some companies make it extremely easy to check the tension range (i.e., some drive units feature a special chain indicator slot through which a pin clearly indicates the location of the tensioner).

Inspect and, if necessary, lubricate flat-top or roller chains, sprockets and corresponding guides.

Monthly maintenance
In addition to the above daily and weekly procedures, monthly maintenance actions you should take include lubricating toothed belts with light-grade oil. Also check for loose or missing fasteners, and tighten or replace them as needed.

Side guards on drive and return units are also locations where debris can accumulate. Thus, it’s imperative that these components be removed once a month and cleaned. Small parts can fall and get caught between the belt and guide profile, and cause tremendous damage to the belt, guide profiles, drives or returns.

It’s also essential to verify that all cooling components are running efficiently. Excess heat leads to increased wear, poor system performance and premature belt failure. To ensure the best possible performance, wipe any dirt or grime from the fan shrouds of all motors to maintain proper motor cooling.

Through heavy use, fasteners from the conveyor can also become loose in other key areas, such as on the conveyor’s foundation. Therefore, check for loose or missing fasteners on the structure itself once a month.

Check drive chain tensioners and lubricate drive sprockets as required for maximum performance and system longevity.

Quarterly maintenance
Inspect the condition of the conveyor chain for stretching, wear and correct lubrication on a quarterly basis. As a chain expands, the chain and corresponding drive sprockets wear in unison. But because the sprockets will reach the end of their life cycle and be replaced before the chain, the new sprockets will stretch the chain at a faster pace due to the disagreement in pitch length.

Proper lubrication of flat-top and roller-chain conveyor chains can greatly prolong satisfactory system performance. Skipping lubrication intervals can result in a malfunction or even a failure of the chain or a system crash. Some conveyor manufacturers like Bosch Rexroth offer automatic-lubrication modules and refill cartridge units with drive-specific adapter sets that ensure optimum lubrication directly at the chain links. The module’s continuous operation provides clean and precise lubrication where it’s needed. The cartridges are easy to replace when empty, saving maintenance time. In some cases, automatic lubrication units can be retrofitted to existing conveyors.

Know the signs of failure

In addition to performing regular preventive maintenance, it helps to recognize the signs of conveyor chain failure. These can include:

• Excessive noise during operation
• Erratic movement of drive tensioner pin
• Drive-chain tensioner exceeding maximum travel
• Erratic movement of the chain (commonly referred to as “slip stick”)
• Fretting corrosion (rusting of chain)
• Physical damage (or loss) to the chain clips or rollers

It’s also recommended that conveyor-system operators provide maintenance training on their conveyor systems, as well as take advantage of tune-up and consultation services available from most reputable conveyor suppliers. Some offer professional conveyor service wherein a maintenance expert visits the facility, inspects conveyors in motion, and provides recommendations and solutions to keep them running efficiently.

Debris can also accumulate on drive and return-unit side guards, so it’s imperative that these components be removed once a month and cleaned.

By taking a few minutes regularly to keep your conveyor system in pristine condition, you can save significant time, money and headaches. MT

[box]Quick Tips for Proper Conveyor Maintenance

Taking the time to perform several routine maintenance procedures on assembly conveyors can significantly add to the efficiency and longevity of the system. Follow these tips to keep your conveyors running smoothly:

• Inspect all moving parts for excessive wear, damage and chain stretching.
• Look for missing components where debris can find a home and disrupt the operation.
• Wipe down equipment and remove any visible grease and dirt.
• Lubricate all necessary components and chains on a regular basis.
• Consider installing an automatic lubrication unit to save time on maintenance and ensure adequate lube coverage.
• Remove side guard on drives and return units to check for accumulated debris.
• Make sure cooling elements such as fan shrouds are kept clean.
• Check for loose or missing fasteners on the conveyor’s structure or foundation.[/box]

Information in this article was supplied by Paul Zielbauer, Technical Service Supervisor with Bosch Rexroth Corp. For more maintenance tips, visit boschrexroth-us.com/conveyors.