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  for Metal Finishing since 1989
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Calculations of compressive springs

 

To whom it may concern,

I am helping a company to replace worn out compressive springs from a mechanical vibratory tumbler also known as finishing mill. Right now I have replaced the old springs to new ones but I need to test its stiffness and compressive strength of these new springs if they match with the old ones.

I have asked a couple of companies specialize in testing the springs but I have been told that I need to work out some calculations first. I need to calculate if the springs are equally subjected to the load which is 2100 pounds.

I would like to know where can I get the necessary formulas. I would appreciate if you could be able to help me.

Yours faithfully,

Zac Lim Daoying
- Singapore

I don't know that you will have to do a big calculation. Look at the machine. Are the springs evenly spaced around the perimeter of the bowl? Did you try to contact the bowl manufacturer to get the spring specs? I might also look at using a level in various positions across the bowl to see if it sits level. If it sits level, then I would assume that the weight is evenly distributed (assuming that all the springs are alike).

Dan Brewer
chemical process supplier - Gurnee, Illinois

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2006

The easiest way for me to calculate linear springs is to think of them as parts of a circuit. The force can be treated like a current. The displaced distance can be treated like a Voltage, and 1/k (where k is the spring constant) can be treated as resistance. Notice that springs in parallel will have equal deflections, and that springs and series with have equal forces. Note: If you are using belleville springs, the calculations will be much more complex.

Hope I helped,
Jay

Jay Jacobs
Engineering - Pittsburgh, Pennsylvania, US