Clearance Setting for a Tapered Roller Bearing
Clearance Setting for a Tapered Roller Bearing
(OP)
I have many different applications where we utilize tapered roller bearings. When mechanics are assembling these fixtures, they often ask me what the endplay should be. By endplay they mean the initial gap between the bearing and the nut. The gap is needed so as the bearings heat up, they don't expand so much against the nut that it causes excessive heat and premature wear.
Is there a way to calculate this initial gap? Or does anyone know of a link that I can get this info?
Is there a way to calculate this initial gap? Or does anyone know of a link that I can get this info?





RE: Clearance Setting for a Tapered Roller Bearing
RE: Clearance Setting for a Tapered Roller Bearing
RE: Clearance Setting for a Tapered Roller Bearing
Oh, the mechanics do use a dial gage to measure the gap.
RE: Clearance Setting for a Tapered Roller Bearing
Actually, in some cases, if you have a very flexible housing, I think you can get away with zero or negative clearance - that's why I don't think there is a simple technically correct answer to this question. It can be calculated - but requires a coupled thermal - mechanical FE analysis. Even then - the heat generation rate is a bit of a nebulous thing to predict theoretically, especially with grease lube. I'm skeptical that even Timken would do this, at least for free within a short time frame. So we are probably talking about a rule of thumb here.
RE: Clearance Setting for a Tapered Roller Bearing
The end play or pre-load of the tapered roller bearing depends on the application. Though there are thumb rules, but when one needs an exact answer it is better to contact the manufacturers. The setting of the bearing to end play or pre-load can change during the operation due to thermal effects. If you want to find out how much should be the clearance, then you need to determine the losses due to thermal effects and set the bearing to so much clearance that during operation the bearing will reach a line to line contact stage, i.e. the rollers are touching the outer race. Note that if it is a two row bearing then losses due to tight fits also needs to be considered. We should also look in the load zone, operating setting and heat generated when selecting a suitable end play or pre-load.
RE: Clearance Setting for a Tapered Roller Bearing
Obviously you have to know the correct target temp to start with!
Lester Milton
NBC Group Ltd, Telford, Shropshire, UK