Load rating of bearings 1

[ABC7931]

Can anybody tell me the difference between Basic static load rating of a bearing and the Maximum static load of the bearing? I have a bearing manufacturer's catalogue which only gives the maximum static and dynamic load the bearing can withstand. Do i assume it means basic static load rating?

 

[Fugeguy]

Same thing.

The basic static load rating is the maximum radial or axial load the bering can sustain without permanent deformation.

"Bearings - Basic static-load rating is the maximum radial or thrust load a bearing can endure without excessive permanent deformation. Maximum deformation of rolling element or race that does not significantly degrade bearing performance is 0.0001 times the diameter of rolling element bearings. Equations for basic static load for standard bearings are given in Sections 9 and 11 of the AFBMA Standards. "

http://www.bearings.machinedesign.com/guiEdits/Content/BDE_6_2/bdemech6_35.aspx

 

[tbuelna]

ABC7931,

The static load capacity of a bearing can vary slightly depending upon its degree of preload. A preloaded bearing will load share among the rolling elements more effectively than a bearing with clearance.

The dynamic load rating is intended to take into account many operating condition adjustment factors to establish a suitable load limit.

Good luck.
Terry

 

[ABC7931]

I have been doing some bearing friction torque calculations. I have available with me the Basic static load rating of the bearing which is usually termed as Cs. I need to calculate a factor which is dependant on the static equivalent load (Fs) and Cs. Now, the static equivalent load can be calculated by the formula : XsFr + YsFa where in Xs is the static radial load factor, and Ys is the static axial load factor and Fr is the radial load and Fa is the axial Load. Does anyone how I can calculate the Fr? or should I take Cs=Fr?

 

[electricpete]

Does anyone how I can calculate the Fr? or should I take Cs=Fr?

Fr is the radial load

=====================================
(2B)+(2B)' ?

 

[tbuelna]

ABC7931,

That equation only applies to certain types of bearings, within a certain ratio of radial to axial loads.

Also, be aware that basic load ratings, whether static or dynamic, must be adjusted for many factors such as mounting mis-alignments and structural stiffnesses.

Good luck,
Terry

 

[ABC7931]

Thanks everyone for their responses. Yes, the above equation can be used only for deep groove ball bearings and thats what I am interested in. I still want to know how do i get to know Fr which is the radial load on th bearing.. I only have the basic static load rating of the bearing with me, which is Cs.

 

[Fugeguy]

The Fr or radial load on the bearing would be application specific. something that would be calculated based on solving a static or dynamics problem based on the loads present.

Go to:

http://www.koyousa.com/brochures/pdfs/catb2001e_a.pdf

and look on page 21 and forward.

If what you are doing is very general I would use 15% of the load rating.

Hope that helps.

 

[ABC7931]

thanks for the help.