Small Rubber Damper Design - Information Please!!
Small Rubber Damper Design - Information Please!!
(OP)
I am designing a small (Dia 26mm x 200mm) roller mechanism that currently uses springs in parallel with relatively expensive oil dampers. I would like find a cheaper solution using rubber parts in series with the spring to replace the oil dampers.
Can anyone recommend any useful sources of data for small rubber damper design?
Many thanks
Matt
Can anyone recommend any useful sources of data for small rubber damper design?
Many thanks
Matt





RE: Small Rubber Damper Design - Information Please!!
Good luck!
Tony G
RE: Small Rubber Damper Design - Information Please!!
The problem with using rubber as the damping element is that the damping factor is not especially high (say 10 degrees loss angle for 65 Shure), especially at low frequency. It is also fairly unrepeatable , that is the damping effect reduces after you've scragged the bush, or on repeated application.
Cheers
Greg Locock
RE: Small Rubber Damper Design - Information Please!!
RE: Small Rubber Damper Design - Information Please!!
Greg: I am only looking at low volumes for this mechanism 500 units = 2000 damper units per year. I currently use an off the shelf miniature oil damper for around 40 Swiss Francs each. My target is to make something much simpler and cheaper perhaps a rubber bush for less than 5 Swiss Francs! I can see that this would not give as good damping qualities but I think I can live with that.
By scragging do you mean over-stressing beyond the elastic limit? If so, how would this apply to a rubber damper element working in compression?
All: I would like to know how to go about choosing the correct size and shape and material for a rubber damper, which will give the best fit over the temperature range 10 to 35°C. Any more advice?
Thanks again
Matt
RE: Small Rubber Damper Design - Information Please!!
Typically after 10 cycles the hysteresis loop has only 1/3 the area of the first cycle.
2000 pa is not enough to justify a fancy rubber bush, I suspect, so I'd forget my hydrobush idea. Your estimated cost for a rubber bush is about right, for one perhpas 30-40 mm on its longest dimension. What duty cycle and life do you need?
That temperature range is fine. I strongly suggest that you talk to a rubber bush manufacturer when designing the part he will be able to guide the design. We often work from a known similar part, test it, and then juggle the geometry to get the desired rates.
Another form of cheap damping is to use foam pads to create friction.
Cheers
Greg Locock
RE: Small Rubber Damper Design - Information Please!!
i also strongly reccomend "EAR" products.
be carefull with friction based dampers because of friction force (static and dynamic) changes with humidity and temprature changes.
sincerely,
lasker
RE: Small Rubber Damper Design - Information Please!!
You might try Sorbothane. They also have free design software that you can download.
RE: Small Rubber Damper Design - Information Please!!
These might solve the problem for you.
Tom Aspin
RE: Small Rubber Damper Design - Information Please!!
- small DC motor mounted between two O rings, rubber pad on side;
- motor drove a blade coupling, which interfaced with a rubber coupling on the worm;
- the worm ran in bushings that were supported in rubber jaws;
- the worm drove a plastic output gear that was spaced within two O rings;
- the gear drove an acme shaft that traversed a shuttle running in rubber bushings;
- the whole actuator was encased in a wrap-around rubber enclosure.
The impression was that this design spared no feature that could act to dampen vibrations and other noise. But the dampers had to relatively inexpensive for the most part.
Yes, consider rubber dampers of all kinds to serve your purposes.