Rib-type axial cam

bill_daniels

I found another thread on barrel cams but my question is a little different.  I need to model an axial cam for two cam followers.  Unlike the groove-type barrel cam, it will have a raised rib with a follower on each side - sort of the inverse of a grooved barrel cam.  This a a bit more complicated in that the width of the rib must change with the pressure angle whereas the groove-type barrel cam groove width is always the same.  The advantage sought is that the cam followers can be pre-loaded axially resulting in a very quiet, smooth running cam.

Anyone have an idea of how to do this?  I know there are very expensive software packages for modeling cams but I only need to do it once.

bill_daniels

You're right.  The contact points (actually lines) are not parallel nor is the angle between them constant except at two points 180 degrees apart. These cams are made and used in industry so there must be some way to model them.

mahir

I'm having trouble picturing what you mean. It sounds like you're talking about just a regular radial cam with two followers.

bill_daniels

It's something like this: http://www.camsoft.it/eng/img/cmm/manuale/nerva.jpg

NeilCooke

If you can get the points that define the splines then you can build it using FeatureScript. If not, then it is probably too difficult to do by hand since the contact points on both rollers is not always along the vertical axis.

bill_daniels

You're right.  The contact points (actually lines) are not parallel nor is the angle between them constant except at two points 180 degrees apart. These cams are made and used in industry so there must be some way to model them.