Washer/Spacer Design 1

[djw2k3]

Hi,
Am currently trying to design a spacer/washer to take a compressive load of 17.65MPa per unit area. The spacer is to be placed between 2 steel plates which rotate around 4 degrees relative to each other. It will be relatively thin - only 4mm. Corrosive environ also (sea spray).

What I would like to know, due to the dynamic conditions would I be on the right track looking at a brass alloy or a nylon plastic?

Thanks in advance
djw

 

[CoryPad]

If the compression force is constant, you should not consider nylon or any other polymer as they are viscoelastic and will result in time-dependent force loss. What is the rotation frequency? Perhaps a coated steel part can be used if there is low frequency, but if the frequency is high, perhaps something closer to bearing alloys would be appropriate.

 

[awol]

Look at a company called Seastrom 1-800-634-2356. They may have the exact size washer, Dia and thickness, in stock, in the material you need for this application.

 

[dooron]

My opinion is that at 17MPa you are close to the limits of the Ultra High Molecular weight Plastics-but check them out because they don't require lubrication. I think that a brass/bronze alloy, and there are many types, can also be considered and may be cheaper. At 4mm thick the sheet will have to be fully supported between the moving parts. The bronze /brass will have to be pre-lubricated or maintenance item.If there is heat then brss/bronze, if there is corrosion, then UHMPs it all depends.