Trailer bearings

[journey on]

OK, I can't resist this. Read at your own risk.

From Design of Machine Elements, Faries, 1955:

"The life of a ball bearing is defined as the number of operational hours at a particular speed, or as the total number of revolutions when evidence of fatigue becomes visible. Fatigue occurs in the form of spalling or flaking of small bits of material from the surface of a ring or a ball/roller, usually of a ring. A roller bearing which has failed does not seize or cause damage to other parts but becomes noisy, thereby giving warning."

When I examined the bearings on the trailer, they showed evidence of spalling. I used galling as a term which more people would be familiar and as a term to describe the damage to the spindle where the seal rubs, as Bob describes above.

So for the bearings the design parameters: load, environment, lubrication and speed, are entered into the manufactures design manual and a bearing size and type is found. Since the bearings on the trailer were from a Chinese manufacturer, there was no design manual (that I could find,) and I just replaced them with the highest quality bearing I could find, Timken. Since roller bearing life is statistical, I hope the probability of failure is low enough to let them last past my lifetime.

As to the galling, that is what I saw on the spindle. Replacing the EZ Loader spindle is done by replacing the axle due to the rubber torsion suspension. Since both leaking seals were on the same side the cost was $1600 plus shipping. Using repair sleeves is a common, accepted practice. It is used in rebuilt motors and auto transmissions as well as spindles.

Boris