Problem No. 3: Premature Wearing of conveyor Chain

Causes:

1. Lack of Lubrication
2. Exposure to Abrasives
3. High Temperatures
4. Corrosion
5. Drives out of Location
6. Drives out of Coordination

Explanation 3.1: A customer may fail to lubricate the conveyor chain because of inadequate maintenance, lack of an oiler, or fear of drippage. In any case, when the chain is not lubricated, the useful life will be drastically decreased. Without an oil film, the connecting pin joints and bearings will wear rapidly. Also, the chain tension will mount to accelerate wear.

Correction 3-1: Ask the customer's lubrication supplier to recommend a proper lubricant, taking into consideration the operating conditions with special attention to temperatures. If the fear of contamination is great, recommend a #LU-669-A oiler which can be regulated to apply the proper amount of material. Also, the oiler should be placed in a section of conveyor where the product is not be transported.

Explanation 3.2: Oftentimes the conveyor will be placed in or near a shot and/or sand blasting machine, or in an area where the air is heavily laden with abrasive particles. The abrasives do find their way into the chain wheel bearings. The oil on the chain actually attracts and holds the gritty substance. In some cases, the bearings clog and the wheels will not rotate. If they do continue to turn, the abrasive dust grinds away the bearing cones, races and balls. The chain will, of course, only function for a short period before replacement is necessary.

Correction 3-2: In the case of shot or sand blast machine, the conveyor should be located over the machine cabinet tops. Product hooks can then be suspended through a very narrow slot in the cabinet top with rubber seals at both sides. In other situations, the Protectaire equipment can be used to prevent the abrasive dust from entering the conveyor track.

Explanation 3.3: Burn-off and glass tempering ovens, plus certain other types of equipment operate at temperatures reaching 1000 Degrees F. and higher. When Zig-Zag, or any other overhead conveyor, is exposed to any temperature above 450°F., the hardening heat treated parts such as pins, wheel cones, races and balls, are softened by annealing. the drop in hardness is in direct relation to the temperature involved. Since the parts mentioned are heat treated (60 Rockwell, C scale) to accommodate certain loading, any hardness reduction accelerates wear.

Correction 3-3: Remove the conveyor from the heat zone by slotting the top of the oven and installing continuous cover plates on the conveyor. Also, replace the conveyor chain.

NOTE: Please consult the factory for quotation and design for this application.

Explanation 3.4: Chain life is drastically shortened when it is exposed to corrosive substances, and particularly acids. The problem usually occurs when the conveyor is used to transport parts through certain washers, paint strippers, etc.

Correction 3-4: See #1-13

Explanation 3.5: In multi-drive systems, the placement and number of drives is critical. An error in this procedure can cause replacement of conveyor chain at short intervals. It is easy to induce extra tension in the chain by placing a drive just upstream from a loaded decline. The force generated by the decline offers help to the drive motor and since all motors in a given system have equal torque, the chain tension is increased.

Correction 3-5: Relocate drives to eliminate the problem.

NOTE: Space does not allow for a complete instruction in drive placement. Also, each system presents its own requirements. Therefore, troublesome jobs should be submitted to the factory for analysis.

Explanation 3.6: In certain multi-drive systems, the drive motors fail to coordinate or work together. Resulting abnormal tensions accelerates wear of the chain.

Correction 3-6: This requires that a complete check of the drives be made as follows: Check all name plates. They must be identical except for the serial numbers. Check all motor drive sprockets. All must have the same number of teeth. Check caterpillar drive sprockets. These must all have the same number of teeth. If it is a constant speed arrangement with a three stage variable transformer, also check the settings. To adjust, the voltage should be reduced gradually until the conveyor stops. Push stop button, advance voltage control about one tenth of a revolution and push start button.

Check amperage at each motor. If any motor or motors should indicate readings much higher than the others, this motor should be sent to motor repair for checking and correction.

NOTE: When ordering drive motors, please provide drive serial number, all motor name plate data, including serial numbers, and controller name plate data. This is all necessary if the factory is to supply a new drive motor or controller parts.