What is Axial Load Rating of R4 Ball Bearing 1

[chrispe]

Guys:
I am having really trouble determing the bearing I need for this application. I have been using an R4, but replaced it with an R4a bearing. Both deep groove.

The axial (thrust) load is 300 lbs, the radial load is about 50 lbs. Rather then angular contact, or thrust bearing I need to use a standard deep groove bearing. (cost issues) I think the R4 and R4a are too small, but can't find information on the web. What would be the equivalent R series bearing I would need for these loads ?

I need to maintain an equivalent friction coeficient of about .05 or less and think the r4a bearings are binding. The speed varies but at the high load, it is less then 1000 rpm.

thanks

 

[electricpete]

What does R4 and R4A mean?

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[chrispe]

Sorry. R4 is a 1/4" bearing rated at a dynamic load capacity of 486 lbs, the r4a is a 1/4" bearing with a dynamic load capacity of 545 lbs. The r4a is a slightly bigger od. I plan on replacing with an r6 which is a 3/8" bearing with dynamic rating of 750 lbs.

The shaft doesnt run at constant speed but is an intermittant indexing style movement. (ie It runs from 0 rpm to 5,000 rpm and back to zero again)

 

[MASSEY]

Bad news chrispe:

For these small bearing series the max axial load should not exeed 0.25 of the static load rating.

In other words if you want 300 lbs. axial load capacity your static load rating should exceed 1200lbs. Which starts somewhere around an R14. Or metrics: 6005, 6204, 6302, etc.

I know this is bad news, but check it out at SKF or some other reputable bearing manufacturer.

Good Luck!