The art of belt tracking. Part 2.
Picture above. Artists view of Prime-Tracker ©.
Conveyor belt tracking boils down to two words:
A. Misalignment of a belt installed in a conveyor can have many causes.
Belt Tracking Basics
The first step is to make sure that your conveyor is installed squarely and that the belt you are using has been cut and spliced correctly. If a conveyor has been installed out of square or the belt is not properly cut or spliced, tracking the belt will be a difficult or impossible task.
Next step to see to that all idlers are square to conveyor frame.
Normally belt shall now run centred.
There are more reasons for belt running sideways than my imagination can serve me. This is the time when a belt tracker will do the job.
B. Misconception. A belt tracker has the mission to bring belt back to straight line. This is simple and we all agree.
A tracker for return belt is one or more rolls mounted on a pivot enabling the roll to swing, often only in horizontal mood. This is fine, but many makers believe they need to add crowned or other high points on the tracker.
This is misconception and wrong doing! The tracker will have many different peripheral speeds. If the tracker is crowned, edges will run with peripheral speed activated by centre part and edges will be worn out. If the tracker is in an idling position it should be running freely. This is not the case with different diameters and will act as brakes and will be in a sliding mood all the time. Consequently, tracker edges or high points are worn out, belt is worn and extra energy is consumed to make part of the tracker slide, ALL THE TIME!
My question is why make complicated trackers? The probable answer is that design engineers have looked at competitors and carried on. Not one single thought about trying to understand why so many trackers are poor trackers resulting in short life time and high costs for the customer.
My belief is that engineers have looked at crowned pulleys and hoped it would work to return the tracker back to its original position after it has swung. This is a Misconception!
The situation is as follows. The Belt runs with equal load on both sides of the pivot point. This is equilibrium. Now the belt travels sideways and the tracker swings and steers the belt back to equilibrium. When belt has reached the position of same the load on both sides of pivot, the tracker is idling. This is the case with a cylindrical tracker. The load of the belt and movement sideways is all we need for a good behaving belt tracker.
One more quality is asked for to be the best tracker. It is the vertical movement. When the belt moves sideways the belt tilts. The load of belt is now higher in the area the belt is moving to. The tracker must be in full contact with the belt along the length of the tracker to do the best tracking job. This is when tilting ability is so important. Load of belt is always distributed along full length of tracker. This is a mode not many trackers offer.
We at Versum in Sweden and Transroll in Czech Republic have done some thinking and brought Prime-Tracker© into the market. It is a cylindrical tracker with a rubber pivot that can´t be destroyed of intruding sand an impurity.
Prime-Tracker© does the job! Do you want more information, send us a mail.