coefficient of friction for caged versus non-caged needle bearings 1

[John2004]

Hi everyone,

Can anyone please tell me the general difference between the coefficient of friction of a caged needle roller bearing versus a non-caged bearing of the same size ?

I'm trying to get a general idea as to the difference in the coefficient of friction for a caged drawn cup needle roller versus a full complement drawn cup needle roller, i.e., how much more friction is added for a full complement needle roller that is loaded with needles, as compared to a caged needle roller bearing ?

Thanks
John

 

[israelkk]

Here is a quote from the Torrington catalog:

"Coefficient of friction - generally, the power loss in a rolling element
bearing is so slight it can be ignored. Occasionally, the coefficient of
friction must be known. The coefficient depends on many variables,
such as speed, magnitude of load and lubricant viscosity and flow rate.
In a caged bearing, the frictional loss is less than in a full complement
bearing because the cage improves roller guidance and reduces
rubbing velocities by eliminating roller-to-roller contact.
No accurate method exists for predicting the coefficient of friction of
a specific bearing under all conditions of operation. Approximate values
for bearing friction under normal loads with oil lubrication have been
established by test. From such tests, the coefficients of friction for radial
bearings are:
caged needle roller bearings = 15 • 10-4 = 0.0015
full complement needle roller bearings = 25 • 10-4 = 0.0025

 

[John2004]

Thanks for the info Israelkk,

John