Industrial Chains Maintenance & Technical:-
Most Can-Am Chains products can be ordered with mechanical properties to suit specific applications.
Some of the variables are listed below.
- Non heat treated sidebars, barrels or rivets
- Through heat treated sidebars, barrels or rivets
- Induction hardening of already through hardened sidebars, barrels and rivets
- Shot peened rivets
- Prelubricated chain, (molyslip or other)
- Construction by means of standard riveting, welded rivets, or pins
Note: All standard mill class chains are supplied with heat treated rivets.
WELDING PROCEDURE FOR CAN-AM STEEL CHAIN
Preheat chain and attachments to 93°-176° before welding. Preheat temperature is affected by many variables, some are thickness of material, geometry of attachment, and composition of steel.
1, Use dry 7018 electrode, or #116 flux core, or wire feed with argon/CO2 shield.
2, Always observe proper welding techniques.
Note: CAN-AM Chains is not responsible for chain, or attachment failure, or welding defects, when ex-factory welding is the cause of the failure or defect, and that welding has been performed by other than our own factory certified welders.
Normal chain wear is often the result of friction between the rivet and the ID of the barrel. Sprocket size and pitch angle will determine the relative motion between parts, and the degree of wear.
Lubrication of these surfaces would reduce wear and slow the process of corrosion.
Since lubrication significantly reduces the amount of wear to the chain, it would seem to be good economics to pre-lube the chain at the point of manufacture and to lubricate that chain throughout its service life. Even a fine spray of water adds to service life.
Following a proper and logical break-in routine will enhance the service life of welded steel chain products.
1, Chain should run empty for a period of 6-8 hours, or whatever is practical. A fine spray of water or other lubricant promote the surfaces to polish up.
2, Make sure sprockets are correctly aligned and that wear strip is in good condition.
3, New chain should always be run on new sprockets. Even if the sprockets are only slightly out of pitch, of have even the smallest “hook” to the teeth, those sprockets will dramatically reduce chain life.
4, Check to ensure that the chain will not ‘bind’ or ‘hang up’ along the conveyor path.
SIDELIFT LOG HAUL CONVEYORS
The following recommendations will help in the maintenance of existing conveyors and the design and installation of new systems.
1, Chain height- This dimension is controlled by the angle of incline in degrees of the conveyor. The most satisfactory incline is 30°. Using that figure the chain height should be 1/3 the diameter of the largest log expected. In other words a 900mm diameter Log must have a chain height of 300mm minimum.
2, Head end design- The sprocket centre must be far enough back from the end of the log haul conveyor to allow for a skid between the top of the sprocket and the end of the log haul conveyor trough. If this were not designed in this manner, the chain could bump it as it travels around on its way back down the side lift conveyor.
3, Chain return- A catenary return is best for chains and conveyor structure, and the slack of the chain should be 5-10% of the sprocket centres.
CONVEYOR INSTALLATION AND MAINTENANCE FOR THE FOREST PRODUCTS INDUSTRY
CAN-AM Welded steel chains are manufactured of high quality steels, not available ‘off the shelf’ from any steel supplier. These steels, in combination with careful design and expert manufacturing, have produced a high quality chain product that will give superior life and performance when properly maintained.
The recommendations in this catalogue are based on our own experience and observations after almost 40 years of manufacturing chain for the forest products and other industries. The thoughts and suggestions of millrights, maintenance people, engineers and others have contributed to our philosophy of the maintenance of chain in an industrial environment.
INSTALLATION OF A NEW CHAIN IN A NEW CONVEYOR
Check the following:
1, The width of the trough need not be more than 12mm wider, on each side, than overall width of the chain including attachments. Chains should not wander from side to side.
2, The wear strip must be the full width of the conveyor so that the chain runs on the sidebar, the barrel of the chain does not support the chain itself.
3, Chains that run in a trough should be at the correct height. Half the height of the sidebar is a good rule of thumb. If the chain is too low, the logs or boards will be slowed in their movement. Conversely, a chain running too high in the trough can be easily forced out of the trough by side loads.
4, The root line of the sprocket or drum should be approximately 12mm above the level of the conveyor wear strip. This allows the chain to be lifted slightly as it contacts the sprocket. The benefits are: immediate contact with the sprocket tooth, rather than 1/3 the way around the drum, and, improved wear life. A low root line relationship between the sprocket and the wear strip causes the chain to be pulled down across the end of the wear strip. This causes premature wear on the side bars.
5, Be certain the chain has the correct amount of slack on the return. A good rule of thumb for conveyor chain is 5-10% of a sprocket centres depending on the size and weight of the chain.
6, Pay as much attention to the chain return as to the load side. Use a trough if possible. If not, again, the correct amount of slack is important. Too much that can cause the chain to sway or jump – a condition that increases chain wear.
7, The last step is never to be forgotten for successful operation. Breaking in a new chain is a very important procedure. The chain should be run, no load, for a few hours (6-8). This will smooth up the chain running surfaces as well as the wear strip and the sprocket tooth face and allow the rivet OD and Barrel ID to polish up. This will ensure maximum life. It is advisable to have a film of clean water on the chain during the break-in, and for that matter all the time. Water is an excellent lubricant because it will carry away the dirt generated by the chain rubbing the wear strip and sprocket. A fine spray on the chain at the tail end is enough. It is not necessary to have so much water then it makes a mess under the conveyor.
CUT DOWN ON MAINTENANCE COSTS
1, The overall width of the attachment including the link should not exceed twice the length of the training pitch. For example WR132 is 6.050 pitch x =12.1″ so, 13 inch cradle would be suitable. Anything longer may cause the chain to twist under leverage and break the link.
2, Head and tail sprockets, when used with attachment chain should be flanged to locate the attachment when it enters and travels around the sprocket. Flanges are meant only to locate the attachment, not support it. If contact is made, fatigue failures may occur on the attachment Welds. Remember to mount the sprocket or idler so that the route line is slightly higher than the wear strip.
3, Flare the trough and return ends slightly to prevent the attachments from hanging up on a squared edge.
4, Wear strips must be the full width of the conveyor to support the attachments.
5, The preferred where strip is a minimum of 450 BHN plate or one of several hardened and UHWM products, UHWM, of course, has a very low coefficient of friction, and is best suited for non-abrasive locations.
6, Sprocket pitch diameters should be about 4 x the chain pitch, for mill chains, and 3 x the pitch for drag chains. Also, is it better to use sprockets with an odd number of teeth.
7, Sprocket wear, a hooked sprocket tooth will eventually hold onto the chain beyond its normal release point. The worst scenario would have the chain “wrap” the sprocket and break or tear up the drive. Install new chain and sprockets when the chain starts to climb the sprocket tooth, the pitch has now elongated due to wear are between the rivet and Barrel and possibly elongation of the sidebar hole. This chain will continue to wear itself and the sprocket more rapidly from this point onward.
8, keep the area around the tail idlers clear and the Idlers themselves turning. Use sprockets if necessary to avoid excess wear on the barrels being dragged around the Idler face, if the idler isn’t functioning, for the small difference in cost, it’s always advisable to install sprockets at the tail end of the conveyor.
9, Keep idlers and drive sprockets aligned.
CONVEYOR CHAIN SELECTION
1, Minimise the number of different sizes of chain in use throughout the mill. Quite often the same chain used on a log deck will also be suitable in a waste conveyor by adding on some weld on cross flights.
2, Conveyor speeds have increased over the years and the chart below, showing the recommended maximum speed. May be of assistance when selecting conveyor chain. Don’t forget that Induction hardened pins and barrels can further increase these maximums. Consult your CAN-AM factory representative.
Note the effect that a larger sprocket has on the maximum conveyor speed.
If larger sprockets are not practical then often the best answer is to go to a smaller pitch chain. The shorter pitch length will be able to run faster over a given diameter sprocket as its pin and barrel articulation will be less than the larger pitch chain.
Also , when reviewing the above, consider using the smaller chain in its XHD version to increase the maximum working load.
3, Chain wear can be affected by many factors. We have listed some below with our suggestions:
Side Bar Wear.
Check the wear strip for galling. Use hard wear plate, (min 400BHN).
Grit and dirt can cause excessive wear and if it cannot be eliminated then induction hardened components will help increase the service life.
UHWM or Nylon wear strips can help reduce wear, friction and horsepower and are best used in an non-abrasive environment.
Pin to Barrel Wear.
Excessive speed and/or load are two common factors. Induction hardened components will help increase the service life.
CAN-AM can also supply chains with special components to tackle these problems, re-greasable pins and specially hardened components are tools we have suggested and used with great success.
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