Mounting Points for Known Length/Stroke Hydraulic Cylinder

[ColonelMonk]

Howdy:

Long time lurker here, first time poster.

I've spent many years in silicon valley working as a design engineer on process/testing equipment for semiconductor industry.

Recent change in career (that I love) has me dusting cobwebs off parts of my brain that I haven't used in a few decades, which leaves me with this problem.

I have a simple pivot bar which is actuated by a hydraulic cylinder.

I'm changing a design that we already have slightly for a different application, and I'm under some pressure to use the exact same hydraulic cylinder. The cylinder mounting points are not in the same locations anymore, though they could be "similar"

Seemed easy at first, but now that I'm in the thick of it, not as easy a task as I remember.

I'm working on a sketch to post to show what I'm doing, but I thought I'd jump start the discussion and ask you all if there was some online design resources you're aware of that deals with hydraulic pivot locations and system design for hydraulics.

Sure, it would be simple to just spec a new "custom length" cylinder, which is what this one is, spec'd by my predecessor - but certainly, this problem has got to come up all the time when wanting to use a standard off the shelf cylinder. Fact is, had the previous engineer figured this out, we'd be using a standard

I have searched but no doubt not using the proper terminology to find what I'm looking for.

Many thanks, stay tuned for my sketch.

CM

 

[Jboggs]

Sounds like you don't have a hydraulic problem, you have a mechanical problem. More accurately a geometry problem. A sketch will help a lot. Is this a rear clevis mount cylinder? Trunnion mount?

 

[drawoh]

ColonelMonk,

This is what CAD is for. Failing that, this is what a drafting board is for. If you lay everything out to scale, you will see where everything fits. If you are still on a drafting board, the calculations you must do will be obvious, and you will have to scale drawing to check your numbers.

--
JHG

 

[ColonelMonk]

Hey Guys

The octane of the coffee must have been too low this am. I'm rolling my eyes at myself for not immediately seeing the answer, but I figured it out in tandem with your replies. As I was sketching it the answer bit me hind end...

Pretty sure my messing around with the pivot locations in assy instead of just sketching it first was part of the problem, bad fork in the road. Not to mention I'm using a CAD tool that I hate, and where throwing a layout sketch in an assy seems an afterthought....

Thanks for sending me the lacking morning brainpower over the interwebs.

CM