Motion Simulation of Valvetrains

[Aled87]

Hi guys
I'm attempting to generate movement of rotation into translation between cams and tappets in a valvetrain in NX motion simulation, what kind of joints would i need to use for this?, any constraints to be applied?

many thanks

 

[uwam2ie]

revolute I think / a picture would help

 

[JohnRBaker]

What version of NX are you using?

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

UG/NX Museum:

http://www.plmworld.org/p/cm/ld/fid=209

To an Engineer, the glass is twice as big as it needs to be.

 

[JohnRBaker]

OK, I built (in NX 6.0) a simple assembly of a Cam and Follower (files attached below), however I've NOT used Motion Simulation but rather just created the appropriate Assembly Constraints. To see the motion of the Cam Follower, open the assembly file (with partial loading OFF) and then go into Move Component and select the Cam and then using the Dynamic option, rotate it (slowly) to see the motion. Note that there is a trick and that if that you need to have a smooth face with no seams in it for the face of the Cam whe you create the Touch constraint between the Cam face and the Followerd face. So there's an extra face which you can see if you set the Cam's Reference Set to 'Entire Part'.

Anyway, give it a look and see if this helps any.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

UG/NX Museum:

http://www.plmworld.org/p/cm/ld/fid=209

To an Engineer, the glass is twice as big as it needs to be.

 

[uwam2ie]

I thaught about a rocker arm / motion simualtion
John,
thank you for the example.
I started to rework it, understand, after some rotations movements the constraint flips. See attached picture, how can I prevent this situation?
thanks

 

[JohnRBaker]

That's why I said to rotate it SLOWLY ;-)

I think I need to constrain it differently. If I get something better I'll post it.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

UG/NX Museum:

http://www.plmworld.org/p/cm/ld/fid=209

To an Engineer, the glass is twice as big as it needs to be.

 

[uwam2ie]

Fyi John,
I found a solution, I have extracted in the follower part the cylindric face as complex face and used it for constraint.
I love to workaround , ;-)