Use of "O-Ring" as a spring

[pdizon]

Hello,

I am evaluating a design that uses a silicone o-ring as a bumper. The o-ring has a 2 mm diameter and compresses 30% to 50% under load.

Can anyone tell me if 50% compression will cause any problems such as a permanent set in this type of material?

Advice is appreciated. Thanks.

 

[GRPatel]

You can adress your question to:
mhalloran@parker.com
I presuume you want to use it as spring and not as a damper. You will have to consider temperature and the long time stability, though silicon offers good stability.

 

[pdizon]

Hello GRPatel,

Thanks for the contact.

 

[GRPatel]

I give you some more inputs.
Deformation of rubber spring consists of elastic distortion and creep dependent on stress amplitude and time. The creep under static load can be added a permenant set under dynamic load during first 5x 10^5 stress cycles. After load alleviation and a reflux due to residual stresses a noticeable , material related set may remain (DIN53 517, DIN 53518)The appearance of creep (flow) and permenant set is considerably more marked in synthetic rubber compounds than in highly elastic natural rubber compounds.Even highly elastic rubber compounds begin to creep considerably at 80 deg C.

You may refer a book by Dubbel
Handbook of Mechanical Engineering
Published by Springer-Verlag
There is a full chapter on such springs.
Good luck.

 

neoprene might actually be a better material if you are concerned solely with compression set. 50% is a bit much, I'm not sure what kind of cycle life you'll get out of it