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Modelling Hydraulic (Pneumatic) Cylinders

prohammy

New member
Hey Y'all,


Following from a PM with Mloew, I've decided to ask a general question about you're modelling practices for Hydraulic/Pneumatic cylinders (I have a specific way that I model them, but it has some inherant problems)


So here's the question for all you people out there in electronland.


Given a hydraulic/pneumatic cylinder (ie pre-defined stroke and closed/open centres) how to you model this into an assembly of moving parts........


Kev


PS I am interested to see everyone's approach to what is a generalised design scenario and later on in the discussion I will bring in a specific case that causes me grief when I use my approach and see where we go from there.....
 
easy :)

download the model from the company website.

1.Load it up.
2.Mechanism constraints
3.rename to suit my naming system
4.lightly texture.
5.Add all parameters cost - supplier - part number - etc
6.place into my own parts lib

Most major pneumatics - hydraulic suppliers have 3d models which they happily share with any customers. Being able to show your customer a render of your proposed system goes a long long long way.

Also if the company doesn't have a nice user friendly website. You can always goto their competitors ....... as long as your using ISO or standard parts then does it really matter?



Edited by: puppet
 
here is our approach


create the cylinder as an assembly(piston chamber & Piston). assemble it in the assembly, redefine the pistion constaints and give mechanism constraints to the moving parts.
 
if the cylinder is not standard (not downloaded fom some company website) i won't me wasting time to make the assembly of cylinder


i would be using "make flexible" option to attain my intent.


and if it is from company website then i'll be redifining the constraint of cylinder and piston and use it in as mechanism
 
interesting i didn,t used "make flexible" option for this kind of applications. Can you explain a bit clearly your approach towards this.
 
There are TWO aspects here.


One that of modelling and other that of mechanism.


Once upon a time long long ago when Emperror Akbar ruled over India,I was designing Hydraulic and pneumatic cylinders (Drafting Board and AutoCAD release 10).


Coming back to this age, Designing would be as a parametric assembly to facilitate Families of assemblies thru assembly configuration for the stroke, for a particular Bore size. If you wish to include the Bore too, then the End pieces will change.


Start the assembly with a sketch line (say 10 mm depicting stroke) on one plane and a Circle on another plane depicting Bore dia. Use these parameters to control the cylinder length, Piston rod length, Piston dia, Bore dia, End piece size, seals and so on......


Waiting for Prohammy's specific scenario.
 
SRINIVASANIYER1 said:
Waiting for Prohammy's specific scenario.


Srini,


Still keeping an eye on this and I will do the scenario in a while, just want to get a few more posts. I will however tell you all my preferred method of assembly. From other posts you will have seen from me, you may have guessed that I like skeletons and so my methods are based on that principle.


So a cylinder assy for me starts with a skeleton that specifies how I wantthe cylinder to operate (either setting up planes and axes so that I can edit the cylinder stroke, with pro/progam, or setting up a sketch so that I can vary the angle that the cylinder strokes thru). I then create an assy, add the skeleton, create rod and body parts, assemble each part to the skeleton and off we go.....


Kev


PS I'll post the two problems that I have wwith the above approach later
 

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