bending moments in bearings 1

[valintine]

I am trying to work out how to calculate the bending moment in a linear bearing, and I can`t seem to find any formula or information on the topic. I would be most grateful if someone could help!!

 

[ChrisGW]

I work for a linear bearing manufacturer. Can you better explain what you are looking for? It sounds like you are trying calculate the deflection for a linear rail that is not mounted to a structure - in which case you use standard beam deflection equations and get the moment of inertia for the rail crosssection from the bearing manufacturer.

 

[valintine]

Thanks for your help! that was exactly what the problem was, and that was the solution i used! thanks again!!

 

[ChrisGW]

You will want to watch your deflections. Most linear bearings have plastic end caps that will be damaged if the rail deflects too much.

We generally don't recommend using the rail itself as a structural memeber because of this. I have seen some applications that work ok with a free mounted rail - ussually it's small loading and short strokes.

There are some rails on the market that are specifically designed to be used as a structural member - the rail is shaped like an I-Beam.

 

[valintine]

It worked fine! The deflection was only about .2 of a mill. I auctually used two rails and a power screw so the three of them each took there own streeses and strains!