How to make this gearing rotate properly

konstantin_shiriazdanov

I created a gearing with intermediate rolling elements, but can't make all the rollers move properly because pin slot mates (that should make rollers move in the slots of separator) starting randomly flip direction by 90 deg, when i'm starting to rotate output shaft
https://cad.onshape.com/documents/5b127d8c24b2f4fe30160ab3/w/a4007bd59e449c044bc650ae/e/d39c27f81560c534939f963f
.
this video shows how it really works, though it is in russian
https://www.youtube.com/watch?v=fAamyym1XCk

john_mcclary

https://cad.onshape.com/documents/58fe0d482e4c331084893352/w/ca82f7104e8c8d107ed96cf6/e/6299877fe50016435e5b8a54

It's not perfect, but you may have to look into the profile on the outer ring.
The top roller bearing stays seated while others show gaps.

If you follow my mouse cursor you can see what I mean, it lines up perfect on one side but not the opposite side
https://www.youtube.com/watch?v=FeVg7sP3wVk&feature=youtu.be

Also don't forget the intermediate ball bearing between the cam and the outer roller bearings

konstantin_shiriazdanov

thanks, @john_mcclary, looks like this gearing isn't as simple for motion exploration as I thought. if to add two tangent mates to the slot of separator and to the eccentric for each roller it shows the correct motion, but tooo slow

john_mcclary

Side note: Try not to use a tangent mate unless it is a last resort. As you have seen they are very un-reliable. That goes for any CAD I've used.. They like to flip out sometimes

john_mcclary

I'm willing to bet you will need to size your bearing's circumference (B) to be proportional to the surface length of (A) in relation to (C).

But this is over my head

I just buy these gearboxes, not make them

konstantin_shiriazdanov

@john_mcclary if you're referring to slippage and friction of roller to the eccentric in my simlifyed constructon you are right - in the original video they use one additional bearing on the eccentric shaft to reduce that effects.
About tangent mates - I just have to use them to make sure all the rollers are in contact with three part at a time