Eliminating pressure on a rod used for position measurement

[KirbyWan]

Howdy all,

I'm designing tooling to test a hydraulic servo actuator. To actuate/measure the position I have a .156 rod extending out of the pressure enclosure. But at 3000 psi, this rod is still going to experience 50 lbs of force. I had originally designed it with the actuation separate from the measurement so the pressure wasn't a problem, but I can simplify my design if I can do them both using the same rod all in line with the servo. Is there a standard solution to eliminating the hydraulic pressure on an actuating rod?

Thanks,

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[Compositepro]

This is done by balancing the pressure effect. In this case it means to have the rod go through the pressure enclosure at both (opposite) ends ends, so the force on one end cancels the force on the other end.

If that is impractical due to some geometric interference, add a second "pressure enclosure" to the opposite rod end for balance. You may also have to consider friction at the seals.