Orientation of Timken Tapered Roller Bearing

They are ground as a pair. It makes no difference where that dimple is oriented as long as they (both pairs) are oriented in the same direction. They are supposed to match. 12 Oclock is a simple reference point. Shrug

Gunner

"Gunner, you are the same ridiculous liberal f--k you ever where." Scipio

whoops..hit send too fast.

Ive never seen a set of high precision roller bearings however. Virtually all such grade 7 or 8 will be angular contact ball bearings, so I doubt that these rollers were ground together.

I may be wrong, and if so, Id appreciate it if someone speaks up. I dont do many machines with roller bearings in spindles. Least, not the smaller high precision ones

Gunner

"Gunner, you are the same ridiculous liberal f--k you ever where." Scipio

I havent worked with tapered rollers in quite a while, except for in the case of wheel bearings and such, so my reply is for Gunner, and concerns angular contact bearings mostly.

Angular contact bearings have "arrows" that should be lined up, particularily when they are mounted in a duplex arrangement with the pairs contacting each other or physically located within a close distance from each other on the shaft being separated only by a pair of short spacers.

The way I understand it, ( and I might be wrong ) if you were to hold the inner race stationary and spin the outer, the arrows will show you where the "high point" is at..........

These arrows also serve as a secondary reminder for to aid you in getting your thrust directions correct--very bad news if one out of a pair were to get mounted backwards...........

Looks like AHR has many of the legacy bearing manufacturing companys and has consolidated them under their RHP product line--tons of excellent technical data on their website if one takes the time to root around a bit.

spindle

The mark does matter.All precision spindle bearings are so marked and the marks must be lined up even between front and rear bearings.There should also be marks on the outer races which should be in line when fitting the spindle into the housing.The marks are the high point of the eccentricity in the bearings and if not lined up you may experience vibration at the higher end of the revs. My next job is spindle bearings on a Warner Swasey WSC12.I think they are called 1SC`s over there.It has three angular contact bearings at the front and one at the back and the book keeps reminding you to line up the marks for the above reasons. regards,Mark.

Your reply sure has my attention and should scare the hell out of anyone who is facing any messing around with precision bearing 'pairs'. Dig deep - get the straight 'goods' and do not guess!! If Gunner has questions really pay attention!!

Ken.

Not a real big deal if you take time to study them a bit.

Mainly what you need to be real careful of is in buying unmatched sets, ( ebay anyone ) and there only when you are mounting more than two bearings--here you will maybe need to apply shims or grind spacers to different heights, etc.

With a match ground universal mount $et mounted in duplex or further you can easily capture the bearings by simply physically compressing the inner and outer sets an equal amount......

The real bitch only comes in where you have an adjustable preload and so you must maintain this in high speed apps to eliminate the possibility of ball skidding on accel decel.....

Fortunately, on most ( properly engineered ) applications where this is needed, there will also be a spindle chiller so that heat is actively removed, such that the spindle and housing thermal growth will coincide with each other closely and so it wont be a problem.

Other than that, ( IMO ) its better probly to set them up a bit on the tight side, as properly setup bearings do usually tend to get a little smoother before they start into the "getting worse" part of the "failure curve"......

_Dont_ over grease--generally a 1/3 fill is sufficient, and in fact most of it will get slinged off during break in....

Something about heat transfer that Im not goina get into because I aint thought it through enough to be able to give a plausible written explanation, and ( fortunately ) nobody has asked me to as of yet.

Very correct.

Gunner

"Gunner, you are the same ridiculous liberal f--k you ever where." Scipio

I do high precision spindle bearing replacements as part of my livelihood. When the bearings cost $200USD or more each...making sure one gets it dead nuts correct the first time is pretty important as a warranty replacement may cost you a house payment or more.....

I had a guy once tell me I was being anal after watching me do a set of bearings on a Hardinge DSMA. "he just sticks em in"

A month later I charged his company $600 plus the cost of new bearings to replace the ones "he just stuck in" 3 months before. after they seized.

Somewhere kicking around is a kinda sorta FAQ that I wrote about replacing spindle bearings, if anyone has seen it, it may be of some generic assistance in the general steps needed and the care required in doing a replacement.

Gunner, 300+ spindle bearings replaced, and all are still running perfectly (knock on wood)

"Gunner, you are the same ridiculous liberal f--k you ever where." Scipio

That might clear up a bit of a surprise I got a while ago when I went looking for a bearing for the $30 circular saw. They fellow behind the counter said "do you want the cheap one or the expensive one" I asked (I've been bit before) "what's the difference". The cheap one was something like $3, made in asia somewhere. The expensive one was over $15, SKF brand.

No points for guessing which one the saw got.

Ayup. Though for the "common man" the cheapy would probably last his life time. The rest of us would of course get the better bearing.

Gunner

"Gunner, you are the same ridiculous liberal f--k you ever where." Scipio