formula for pressure in a pneumatic cylander

[dino40]

Good day all,
I need the formula to calculate the force applied to the shaft of a pneumatic cylinder. any help would be greatly appreciated.

 

[TGS4]

First principles would be a good place to start. Draw a free body diagram and go from there. Let the forum know how things work out for you.

 

[codeeng]

pressure x area

 

[dino40]

Thanks codeeng,
please take a look at these figures and see if my calculations are correct. I have a cylinder 4" dia. apply 30psi and I get 376.8 pounds of force?

 

[codeeng]

That would be correct but remember most cylinders will have different areas on the outgoing and incoming strokes. You may need to deduct the shaft area for the incoming. Not sure of your particular set-up. Suggest you do a search on the web and read up on the topic.

 

[quark]

The force calculated by you is correct for a forward motion. If you also have to retract the piston to complete the cycle, you should deduct the piston area or else provide the extra pressure for constant force.

 

[monkeydog]

dino40,
Be careful about giving these guys too much information, they just may start running with your project, and take YOUR fun out of it ;-)

 

[dino40]

Thanks to all for your help it is greatly appreciated.

 

[jsummerfield]

Depending upon the design you may need to consider two areas as the stem side has a smaller area reduced by the stem area at the piston.

Use a catalog for the selected actuator to find tables that reflect the forces available at different supply pressures and different stages of travel. Compare the forces or torque applied agaainst the forces or required to start and stop the load (open or close the valve, etc.).

John