Oil Volume in a gearbox

Hi,

Today I'm attempting to take an extruded volume representing oil and
subtract the internals of the gearbox and housings. In the end I would
of course have a valid volume for the oil fill.

The cutout feature does not work to remove an assembly - I assume this
is because it will contain coincident surfaces.

Will a shrinkwrap work? If so, how do I structure it? I'm sure this
can be done with surface features, but boy would that be a tedious
waste of time.

Dave

 

Not sure what you mean by "an extruded volume". If this is an assembly feature, it
really needs to be a separate component.

Should work to remove the volumes you require, a component at a time. If the
functionality isn't available thru 'Insert>Advanced>Cutout from other model' it
should be available under 'Edit>Component Operations>Cutout'. You would want to do
this with only the components that are at least partially submerged and displacing
oil so it might not be that many components. It also doesn't work on packaged
components, so it could be bombing on something set up as a mechanism which it
regards as packaged.

As a feature, no, as a component, it should. And use 'auto hole filling' to avoid
slivers of material. You could also try exporting the assembly as IGES solids,
reimporting as a 'Part' and exporting again.

You could also try creating your component to act as the removing geometry with
'Copy geometry' or 'Copy Shrinkwrap from other model'. It's not necessary to
manually select all the surfaces.

 

Yes, it's an assembly component, and I started by extruding a
rectangular volume that just encompasses the interior of the gearbox.
It's the subtraction of the components that I've yet to accomplish.

I tried this, but after the 3rd or 4th component it started bonking
with geometry errors. I figured it was due to edge-edge contact
between the components, or sliver geometry or something like that.
This issue, and the number of internal component to subtract, is why I
started thinking shrinkwrap.

Not using Mechanism, but thanks for the heads-up.

The IGES is a good idea, but I think we're both aware that it loses
parametricity.

With the shrinkwrap, I assume you mean to: create a shrinkwrap of the
housing and submerged parts, and use that component to do a single
subtraction from the oil volume?

Thanks David.

Dave

 

How many significant immersed and partially immersed parts are we talking about?

 

Dave,
I say do it with surfaces. Not iges them out. Instead create a part called
volume, then assemble it with the main assembly. While in the assembly you
can modify the volume part and use surface copy to get all the components
and it will remain parametric. Does that make sense? That's normally how I
do it and it works really well.
Dave

 

Total immersed parts: about 75. Significant volume: probably 15. I
tried going thru the cutouts with the signficant parts only but it
failed by the third component. (I wonder if changing the accuracy
setting would help - most of the parts are modeled with relative
accuracy, but because they are legacy components used in many other
assemblies I don't want to modify them.)

If I did the surfaces it would take a LONG time I suspect, since not
only would I need to collect all of the surfaces, I'd have to clean up
any holes, coincident surfaces, eliminate clearances, etc. Of course
then it would carry a large failure burden every time something in the
assembly changes.

Thanks for the suggestions. I was kind of hoping there was an elegant
way to remove the whole assembly in a few steps, but apparently there
isn't (at least with the geometry set I'm using). It's just oil
volume, after all.

David

 

Well I tried the cutout again and as with many things Pro/E, today it
decided to work. It was a little tedious making a feature for every
significant intersecting component, but the result is what I wanted.

So the final 'answer' for me was:

Structure:
Top Level Assembly
-- Gearbox and internals(.asm)
-- Oil Volume (.prt) (created in the assembly)

I then edited the oil volume in the context of the top level assembly
and created Shared Data->Cutout feature, selecting a .prt within the
gearbox assembly. Repeat for all significant components.

Dave

 

Accuracy probably contributes, but the root is trying to merge some complicated
shapes into a single solid body.

Maybe worth trying ideas for next time around...

_Create a part and merge the significant parts (or copy surf; select a face,
RMB, Solid Surfs) and Solidify. Do a One Sided Volume analysis and subtract
that from the case volume rep.

_ Create a simp rep of the internal components, assy cut to oil level, subtract
the volume of what's left from case volume. (Shame we can't do a One Sided
Volume of an assy simp rep, huh?)