The last thirty years have seen numerous innovations in conveyor technology that have brought greater safety and efficiency. However, change in this field has not always been necessarily for the better.

One innovation is the introduction of sprockets with an even number of teeth. It was thought that this would offer customers a greater choice when designing chain conveyor systems. However, sprockets with an even number of teeth are not recommended by experienced technical engineers.

If a sprocket has an even number of teeth, the same tooth will be engaged by the same rollers on each rotation, leading to uneven wear and decreased service life. A similar result will occur if the number of teeth in the smaller sprocket is a devisor of the number of pitches on the conveyor chain. Choosing a sprocket with an odd number of teeth, however, will offer you at least double the service life.

Double pitch sprockets are often overlooked nowadays but are ideal for saving on space and have a longer wear life than standard sprockets. Suitable for long pitch chain, double pitch sprockets possess more teeth than a standard sprocket of the same pitch circle diameter and distribute wear evenly across the teeth. If your conveyor chain is compatible, double pitch sprockets are definitely worth considering.

Many of today’s conveyors include electronic load monitoring in the control system. While this is a useful safety feature, technical engineers recommend that these are used in conjunction with shear pin sprockets.

Electronic sensing is ideal where there is a slow increase in load (due to damaged bearings or dirt contamination, for example) as there is time to stop the drive before any damage can occur. In the case of a miss-feed or mechanical breakage, however, where the load increase is sudden, the sensor will not automatically break the connection between the motor and the driven load and extensive damage can be caused to the conveyor chain and attachments. This is why a shear pin sprocket is needed in addition.

Shear pin sprockets may be more expensive than standard sprockets at the outset but will limit downtime and save on replacement costs. If a conveyor becomes overloaded and potentially dangerous, the shear pin will break and stop the conveyor, thus limiting damage. Once the load or obstruction has been cleared, only the shear pin needs to be replaced and the conveyor can quickly start moving again.

In summary, older types of sprocket are often forgotten but offer considerable advantages including long service life, limited damage in case of conveyor breakdown and reduced replacement costs.