wear rate of mechanical component

[autoguru]

I wonder if the wear rate of components such as gears, chains, bearings are directly related to the load on them?

For example, if I run 2 identical gear pairs at the same rpm, but one pair is under a load of only 30 lb, but the other pair is under a heavy load of say, 500 lb.

I would think the lightly loaded gear pair will have a longer life (slower wear rate). But by how much? Is it a linear relationship?

Thanks

 

[GregLocock]

Dunno. You're the guru, you tell us.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[evelrod]

This may not help, however...
Two conveyors of equal demensions (built from same prints but at different sections of the plant) and both chain driven...one conveyor was a "feeder" and lightly loaded the other was a main line unit and fully loaded (both units ran 24/7). It was my casual observation over approx. four years that we replaced the drive on the feeder only once and the main unit was replaced every year. Linear wear rates? Dunno. I don't think enough data present, at least not enough time.
Before I retired we replaced the drive on both units (as well as a smaller intermediate conveyor) with "toothed belt" (Gilmer type) belts capable of carrying the load, read that BIG. Belts were very quiet but the preload on them was rather extreme and, IMO, would lead to premature bearing wear. Luckily, like I said, I retired. Not my problem.

Rod

 

[autoguru]

Thanks for helping. I think I found the answer.

It turns out there is a law called Archard Equation (you can Google it) that say the wear rate (material removal) is directly proportional to the load, sliding distance, and inversely proportional to the hardness of the surface.

So theoretically it's a linear relationship.

 

[Metalguy]

Haven't read your article, but I don't think it's a simple relationship. There is a "galling threshold" for metal combinations, and once that point is reached it's all over.

Very minor differences in lubrication will make big differences in wear rates.