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A DEEP DIVE INTO HOW THE ORIENTATION OF A LINEAR BALL BUSHING BEARING AFFECTS ITS LOAD CAPACITY

To optimise load capacity of your linear ball bushing bearing, you need to orientate it in relation to the applied load. For maximum capacity the linear bearing must be oriented so that the load is distributed between load bearing tracks.

Using a polar graph to map the orientation of your bearing as a factor of maximum capacity, it’s easy to see the relationship between load vs orientation. This is called a load correction graph, and they are included on all Thomson linear ball bushing bearing data sheets to help you.

Here’s what the graphs tell us:

  • Where the load is applied over multiple tracks, the capacity is at its highest
  • Where the load is applied directly over the bearing track, it is at its lowest

What do we need to do?
When the load is only over one set of bearing tracks, we must derate the load capacity by clocking the bearing at a different angle inside its housing to distribute the load over multiple bearing paths – this is known as the correction factor of its maximum load.

What about open linear bearings?
In most cases it’s not practical to position open type linear bearings to maximise load capacity because the shaft supports restrict rotation.

That said, to optimise installation and performance, you should still have a clear understanding of how applying a load in different directions affects the load rating and design of your bearings.

Using polar graphs to map the load correction factor vs load orientation, we can see the forces that push the bearing down onto the rail are the same as with a closed bearing. But the capacity for loads pulling opposite the slot  (trying to pull the bearing off the rail) is greatly reduced. Some bearings can even resist a pull off load of around 25% of its maximum load.

If in doubt ask for support
Optimising load capacity is an important factor in getting the most out of your bearings, so be sure to ask your supplier for technical advice.

Bowman stocks a wide range of Thomson linear ball bushing bearings. DM me your questions on optimising load capacity, stock availability or delivery times.