TAC ball bearing vs tapered roller bearings

[megals]

Please educate me about double row angular contact (DAC) ball bearing hubs versus tapered roller (TR) bearing hubs. I am considering retrofittng a strut and TR hub combo from a previous model to a race car with DAC hubs. At first glance critical measurements seem OK, hub offset, etc

I was under the impression that DACs advantages are manufacturing simplicity and with setting preload, whereas tapered roller bearings are slightly better for axial loads but required 'old school' preload adjustment.

 

[megals]

er, ... not TAC. DAC.

 

[evelrod]

"Old school preload adjustment"??? What the heck is that?

I've used ball and roller bearings in street, drag and, road race cars with few problems with any application. I've use DAC bearings, in two piece, one piece configuration and with either dual ball or dual roller bearings in industrial applications. Preload settings can and ofter are critical in any of these applications. Preload adjustment? Damn skippy!

If your having trouble with this concept, find someone to help that knows the "old school" method. Old school? Come on...

Rod

 

[GregLocock]

Rod, he may be referring to hub units which are all in one cylindrical cartridges which have both sets of bearings built in, and (typically) a small hollow stub axle.

here's one

http://www.ntn.co.jp/english/news/news_files/new_products/news20060804.html

As such they are very much non adjustable.


Cheers

Greg Locock

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

 

[evelrod]

Yes, I understand. However, even the "non adjustable" bearing units often, very often in industrial use, need adjustment (since getting RFI's from Engineering is often too time consuming) if the project is to continue on schedule. I know that may be a bit too "old school"...still, it does get the job done.

For automotive application recently undertaken...I use non adjustable bearings for the Al hubs on my Mini, front and rear. They were supposed to be the HOT setup. Perhaps the reason I have not had problems with them (as most others have) is my willingness to modify the preload with shims, machine work, etc. Dunno. Had I to do them over, I would go back to OEM as these "modern" bearings seem no better than the "old school"!

This site is not where I ordered my Mini parts, but is pretty much the same type store.

http://www.kml-bearing.com/products/bearings/automotive_bearing_catalogue.jsp?c

Rod

 

[patprimmer]

I thought the purpose of the pre-assembled hub units was to remove any real skill from the fitting process to the degree you take the old one off, read the part number, order a replacement, probably wipe off some dirt and maybe de-bur, then slide the new part on and tighten the retaining bolt to somewhere about spec and bending the lock tab into place. No feel or real adjustment nor even packing the bearing necessary.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules

 

[GregLocock]

Correct. As an ex-wheel bearing design engineer the big advantage is in the assembly plant - the spindle becomes a casting with one biggish hole and four bolt holes, and you no longer have to grease and preload the bearings (which is a surprisingly difficult thing to do in a satisfactory fashion with a machine).

But on a race car, no, can't see the point.



Cheers

Greg Locock

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