How to specify and check roller chain tension
How to specify and check roller chain tension
(OP)
I have a roller chain that drives a mechanism. It actually rotates back and forth about 120°. I have a turnbuckle in the middle to allow for tensioning since it's not a continuous running chain and both sprockets are fixed. My question is how to specify the required tension to the assemblers and how to verify that the tension has been attained. I am currently contemplating some kind of load cell and C-clamp arrangement. Can someone help?
Thanks in advance.
Thanks in advance.





RE: How to specify and check roller chain tension
RE: How to specify and check roller chain tension
RE: How to specify and check roller chain tension
RE: How to specify and check roller chain tension
Mike Halloran
Pembroke Pines, FL, USA
RE: How to specify and check roller chain tension
I also advocate for reviewing this application with the chain and sprocket manufacturer(s). Another aspect of determining proper chain tension is the load on the shafts and bearings.
Depending on loads and chain size, you may want to consider a Snapidle-type of tensioner.
RE: How to specify and check roller chain tension
The pitch circle of a sprocket is - well - a circle.
A chain, by its nature of being made up of side plates and rollers, cannot have every bit of its length follow a circle.
That means that as chain is driven around the sprocket, then length from the tangent points is constantly changing.
You need to have a spring in the system somewhere.
RE: How to specify and check roller chain tension
RE: How to specify and check roller chain tension
The adjustment procedure should also include putting the mechanism in a position where the chordal action is at its worst, and setting the turnbuckle so that the spring is just compressed to coilbind at that position, then backing it off to set the tension exactly where you want it.
Mike Halloran
Pembroke Pines, FL, USA
RE: How to specify and check roller chain tension
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Recommended chain slack from this and other sources seems to be 4% to 6% of sprocket distance for horizontal drive arrangements. No force is noted when slack is measured. Chain is not like belts which stretch when a deflection force is applied. So no force is specified when roller chain is deflected to measure slack. Slack would also mean no chain pre-tension. I'd set up minimum slack to allow for chain wear.
Ted
RE: How to specify and check roller chain tension
Thanks again
RE: How to specify and check roller chain tension
Use a continuous chain and one of these?
http://tinyurl.com/63lkmx
Cheers
Harry
RE: How to specify and check roller chain tension
http://www.snapidle.com/
Russell Giuliano
RE: How to specify and check roller chain tension
It is quite common to have one sprocket on a slide with a spring.
RE: How to specify and check roller chain tension
Why not use the motorbike procedure but specify a spring gauge be used to give the required deflection and specify a load in newtons or lbs.?