imaginary housing details

[Tmoose]

I was certain that I'd seen some ball/roller bearing manufacturer info that talked about lead-in angles and chamfers on housing mores and shaft journals.
Similar to info that seal and o-ring manufacturers publish right up front.

Google Searched a bunch of online literature and has come up blank on that feature.

Am I imagining that I've seen such things?

thanks,

Dan T

 

[electricpete]

SKF Bearing Installation and Maintenance Handbook (2007) Figure 5 shows qualitatively:
1. Shaft fillet too large
2. Correct shaft fillet
3. Shaft shoulder too small
4. Shaft shoulder too large
5. Correct shaft shoulder diameter

But I guess you are looking for something more quantitative specifically about the shaft shoulder / filler (and not about the bearing)?

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(2B)+(2B)' ?

 

[electricpete]

Do you have access to ANSI / ABMA Std. 20 - 1996?
Section 6.5 is "Chamfer dimension limits and maximum shaft and housing fillet radii."

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[electricpete]

This gives limits for the bearing chamfers:

http://www.skf.com/us/products/bear...nces/limits-for-chamfer-dimensions/index.html

This discusses shaft and housings

http://www.nsk.com.br/upload/file/NSK_CAT_E1102m_A100-105.pdf

(I'm guessing the last one is what you were looking for)

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[tbuelna]

If I understand the OP correctly, you are asking about the lead-in chamfer size/angle required on an integral shaft journal surface for a cylindrical roller bearing without a separate inner race? If so, the exact size, angle and location of this lead-in chamfer on the shaft journal is very important. The angle needs to be very shallow, 20deg per side or less. The radial chamfer dimension needs to be slightly greater than the max roller drop allowed by the bearing retainer, so that the shaft chamfer can easily guide all the rollers in the complement onto the journal surface. The axial location of the chamfer edge should provide enough margin so that the rollers never contact it under any conditions. This could result in an edge loading condition and high local contact stresses.

 

[geesamand]

I have not seen a bearing manufacturer advise on the features that don't contact the bearing after the bearing is installed. They definitely specify the bore, shoulder, journal, and any chamfers fillets between them, but I can't recall anything else.

Bearings are quite hard - in ordinary materials the "feature" would take on damage not the bearing itself.

 

[electricpete]

ok, I guess I misunderstood. Is a lead-in angle on the end of the shaft.. to help guide the bearing onto shaft? Similar to this for seals?

http://www.skf.com/us/products/seal...haft-requirements/lead-in-chamfers/index.html

If so, I would think the radius on the bearing accomplishes the same function. I'm probably misunderstanding something though.

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[MikeHalloran]

The radius on the bearing is rarely actually tangent to either adjacent surface, so it's effectively a chamfer at the cylindrical intersections, and it's usually way too steep to serve as a lead-in chamfer. It's also hardly ever concentric with the cylindrical surfaces, so the effective chamfer angle is different all around the periphery. Relying on that radius, and/or a too-steep lead-in chamfer (>7deg, imho), is pretty much guaranteed to misalign the bearing with the shaft or bore at first contact, when alignment is most critical.

Mike Halloran
Pembroke Pines, FL, USA