What causes whistling noise from chain and sprockets?

[mrajm]

hi..
can someone help me out with noise in engines..
i am specifically interested in noise due to running of chain on sprockets..
it is a sort of whistling noise...
which are those parameters in design of sprocket and chain which contribute in noise..
we can also talk in terms of different types of designs of chains and sprockets

 

[Bob S]

The only chain inside an automotive internal combustion engine is normally the timing chain, but in modern engines these are often replaced with relatively quiet timing belts.

 

[mrajm]

i am talking of a two wheeler 4 stroke petrol engine.
in my existing design i have a sprocket and roller timing chain..
this is not a silent chain but a roller chain and the noise is prominent at 2000 rpm.
if i reduce the tension of the chain the noise level is reduced.

 

[jack action]

For timing chains, silent chains are usually used. Here is a link for sources of noise & vibration for roller chains:

http://chain-guide.com/basics/2-2-5-noise-and-vibration.html

 

[mrajm]

Thanks Jack action for good link that you have sent...
i have tried to find good silent chain but in the design of my engine there is no provision of silent chain...
only roller chain are available...
can we do something on the sprocket side to remove this noise...
maybe something which can modify the design such that the noise is eliminated..

 

[mrajm]

i think that the basic principle creates noise is rubbing contact between parts..
i think there is some geometry involved in making the design..
is there some before hand information on that..

 

[mrajm]

what are changes we need to do in the original design of a sprocket to compensate for manufacturing tolerances?
how would it change the performance of sprocket?