One of the most common conveyor belt maintenance issues is when the belt slips out of alignment and starts to drift off centre. The process of bringing the belt back to the central path is known as conveyor belt tracking. As the process to track a conveyor belt is a relatively simple one, we’ve put together a quick additional guide to help you get your belt back on track.
Follow these simple steps:
Belt conveyor tracking is the practice of keeping the conveyor belt travelling along the path as it is required. A conveyor belt should not drift off path as it would cause the conveyor to work incorrectly. When installing a new belt there can often be tracking issues, these require adjustments to counter any tracking problems to ensure the conveyor maintains optimal performance. It is best practice to do any belt tracking adjustments whilst the belt conveyor is running. A belt may also need additional tracking adjustments as it is worn in.
Before considering belt conveyor tracking methods it may be of use to give a brief overview of what a belt conveyor consists of. Each of these parts play a role in ensuring correct belt conveyor tracking.
Conveyor belt tracking problems are often blamed on the belts themselves. This is not always the case. Usually the problems can be blamed on poor installation, such as pulleys and rollers not being properly adjusted, or using the wrong belt tracking measures. Sometimes however it’s simply just faulty conveyor design.
Factors that can effect belt tracking include:
To ensure correct belt tracking:
Belt tracking measures can be quite basic, they’re used to maintain a correctly aligned belt in position. In other cases however, additional measures may be required.
A crowned or tapered pulley can aid in belt tracking
As mentioned above, usually a belt will follow a path moving towards the edge of the roller it meets first. In the case of a belt on a crowned pulley, it will travel towards the centre. Whichever side the belt is tracking to, due to the shape the central area is where the belt tension will be higher. As the belt grips onto the central area and the roller pulley continues to turn the belt is re-aligned centrally.
Once the belt reaches the centre however the tension should be even as there is an equal amount of slack on each side of the belt. If the belt begins to go off centre for any reason, the crowned pulley will naturally guide the belt back into the centre. The taper ideally should be very gradual, as you can imagine any angular parts the belt will run over could cause damage to the belt. When performing belt conveyor tracking, there should be enough tension in the conveyor for the belt to conform to the crown pulleys if used.
A guiding pulley, or control pulley, is a snub pulley that is adjustable. As previously mentioned a snub pulley increases the wrap angle of the belt over the drive pulley which improves the traction. These pulleys can be coated with a material to improve friction. Ideally the area of contact for the belt on the guiding pulley should be a minimum of 30 degrees of the pulley circumference.
A guiding profile is a shaped wedge that is added onto running side of the belt. Often V shaped, though other shapes are sometimes used. They are not recommended for general use as belt conveyor tracking assistance as they incur higher productions costs and have a limited scope for use.
A guiding profile is not usually utilised for belts running at high speed as the guiding profiles have a tendency to slip from their running groove. They are suitable however to lessen the effects of transverse forces on the belt, such as occasions where side loading is required. In wider belts, or belts of thinner material it is recommended to use two guiding profiles, one located at each edge of the belt rather than one centrally.
Where a belt has a v-guide in the underside, often the pulley will be straight faced, as there is no need for the pulley to have a crowned shape, the guide alone should keep the belt centred as required.
