calculating bearing radial load
calculating bearing radial load
(OP)
I am having a bad day evidently. I have forgotten how to run calculations for radial load on a bearing. Does any one have a good reference for this type of work or guidance along the subject? Thanks in advance.





RE: calculating bearing radial load
INA has very good information in their catalogs, but I'm not sure if its available online.
RE: calculating bearing radial load
trying to run, static or dynamic
capacities? AFBMA has formulas
to calculate these. Or are you
asking how do you calculate the
radial forces for your application?
RE: calculating bearing radial load
RE: calculating bearing radial load
determining the true loads and duty cycles
that the manufacturer needs to select the
proper bearing. This plus the size restraints
determine whether to use a ball bearing,
cross roller bearing or a combination
bearing. You should contact several bearing
manufacturer's. If you have the correct
application data ie loads, duty cycles, etc,
then they can give you the expected life as
well as the static safety factors. Try,
INA, KAYDON, PSL, ROTEK, GEAR PRODUCTS, and
check for other manufacturers of heavy
industrial bearing suppliers. They do the
load calculation for free. If you know the
bearing manufacturer of the bearing you are
using, they should be able to give you free
information. If you do not feel that they
are reliable, then check with the others.
Also check the application guidelines as to
how to mount the bearing and also the lubrication
guidelines to make certain that you are in
compliance with their recommendations.
Not an easy task. Sometimes simply adding
a pilot or spigot support can help keep the
bearing loads more uniformly supported.
RE: calculating bearing radial load
RE: calculating bearing radial load
RE: calculating bearing radial load
These are too often used as they are cheap and easy to fit.Your shaft support also dependant on the grubscrews in the inner rings and nothing else.
You don't appear to mention the type of failure, but contamination would be a consideration, as well as the axial and radial loads (of course). And you don't offer much detail with regard to size of impeller, shaft size, speeds etc. So what I say may be slightly off course.
Once you have either estimated or calculated the forces involved, consider using flanged bearing units that have either small double row self aliging ball bearings or even small spherical roller bearings in (use sealed ones even inside the sealed housing if contamination is a significant problem); step the shaft to ensure proper transfer of the axial forces to the bearings and ensure for adequate lubricant (to keep contaminats out more than anything). Retain the bearings in place either by proper interference fits (with stepped shafts) or use adapter sleeves.
If your impeller is really big you may have to use a spherical thrust bearing to support the shaft - but that might be 'over the top' from what I understand from your postings.
Hope this helps.
Lester Milton
Telford, Shropshire, UK
RE: calculating bearing radial load
RE: calculating bearing radial load
Impeller size and speed don't concern me at this stage, but your need to control the clearance would make me move away from ball bearings and spherical roller bearings (which will inherently have some axial clearance) and look at either tapered roller units or angular contact ball bearings that I could set up in a preloaded system and control the clearance. This could be done in the 'top' housing (drive end) with a simple NU cylindrical roller at the bottom for radial load/ guide purposes only.
If that clearance is critical I don't see any other way around it.
4" tapers would handle whatever load you have - I wouldn't waste too much time with huge calculations.
Lester Milton
Telford, Shropshire, UK
RE: calculating bearing radial load