Chain and sprocket drives are a traditional power transmission/motion technique. In general such drives tend to perform admirably well in harsh environments and feature high wear resistance and fatigue strength. Among one of the persistent down sides is the noise generated by chain and sprocket systems.
There are a few common causes of noise in chain systems. The main cause is from the chain engaging with the sprocket; that is, the impact force of the chain links meshing with the sprocket teeth. Especially if both chain and sprocket are metallic they will tend to generate more noise.
There are a number of ways to reduce noise in chain and sprocket drives. For one, consider the chain material. Metal on metal interaction makes the most noise, as opposed to plastic on plastic or even metal on plastic. So the use of plastic can significantly reduce chain noise. In fact, some recommendations include using plastic rollers in the chain length as a way to dampen noise. Other manufactures use different techniques such as spring rollers to absorb some of the energy of the chain and sprocket contact and thereby reduce noise. In such cases, the claim is that using so-called low-noise roller chain can lower noise by as much as 10 db, which is roughly a 50% reduction in noise levels.
A number of other techniques can also help reduce noise levels. For instance, the speed of the drive can make a difference. Generally speaking, the lower the speed at which the chain is run the quieter it will be. Increase the speed and the noise increases too. Something else to consider is using a smaller chain if possible. This decreases the chain weight and the noise generated by the chain-sprocket interaction. Another simple but sometimes overlooked factor is to make sure the tolerances between the chain and sprocket are tight. Loose chain makes for more noise when the chain hits the sprocket and a tighter fit reduces noise. Lastly, don’t forget about lubrication. A properly lubricated chain dampens the chain-sprocket interaction. The lubricant forms a film on the chain providing a kind of cushion for the metal parts interacting and thereby reducing noise.
Amazingly enough, the option of “silent chain” is not even mentioned in this article. And yet it does provide a very large reduction in the sound level, as well as having a better lifetime. Of course, silent chain will not run on roller chain sprockets.