Bearing choice...

[rjwoods77]

I read through all the old threads and such so I dont need to reread them. I know i have to do bearing calculations, which i will get to but i am just trying to figure out some rough packaging at this moment. I am using splined centers on the front and rear and am getting stubs machined up to match. The bearing that all the sprint guys use is a 6010 bearing but made into a double row. Custom jobber so dont bother looking it up. I think the thing is way overkill and too big in size. I was looking into using 2 smaller radial bearings. The double row is a 50x80x35. I found these 61809(45x58x7)bearings that would package nice for everything i am doing but the load rating seems to be too light. I know I have to calculate it all out but i was just wondering if anyone had used anything with a dynamic load rating of 1300lbs and a static of 600lbs. I think the fatigue rating is 130lbs. These are going around a 1.75" shaft with a spacing collar. between the shaft and the bearing. OD. is the factor i am trying to get down as small as i can which this bearing is it.

[rjwoods77]

I read through all the old threads and such so I dont need to reread them. I know i have to do bearing calculations, which i will get to but i am just trying to figure out some rough packaging at this moment. I am using splined centers on the front and rear and am getting stubs machined up to match. The bearing that all the sprint guys use is a 6010 bearing but made into a double row. Custom jobber so dont bother looking it up. I think the thing is way overkill and too big in size. I was looking into using 2 smaller radial bearings. The double row is a 50x80x35. I found these 61809(45x58x7)bearings that would package nice for everything i am doing but the load rating seems to be too light. I know I have to calculate it all out but i was just wondering if anyone had used anything with a dynamic load rating of 1300lbs and a static of 600lbs. I think the fatigue rating is 130lbs. These are going around a 1.75" shaft with a spacing collar. between the shaft and the bearing. OD. is the factor i am trying to get down as small as i can which this bearing is it.

[SnailRacer]

We ran splined axles all the way around in 05, but used the micro-sprint splined bearing sleeves and a pair of 6910 bearings (50x72x12), which were more than adequate. For your app I'd give an extra 10 mm and go for the 6909's (45x68x12), which steps up to 3400/2530 lb load ratings. 1300/600 is a bit small in my mind.

[jack]

remember that bearings with a large OD and thin section get very expensive...and could back you into a corner.

[Frank]

Bearing "calculations" will give some HEAVY stuff

These days I make the theoretical (steady state) bearing loads = the maximum static load rating (which causes Brinelling) of the bearing

(2) of deep groove 35/55/10 (mm) at 45mm centerline spacing (my pick)

I saw you're talking double row, I always thought they get big heavy and expensive

Anyhow, best of luck with it

if you use two bearings, keep the centerline spacing above 40 mm or you might get bad compliance due to the bearing's inherent compliance (your compliance will be proportional to bearing centerline spacing ^2)

[Z]

Yeah, those thin ring bearing$$$...

Rob, have a look around a car wrecking yard. Its amazing how small the axles/bearings of production cars are nowadays. Now mostly angular contact units ie. wheel-flange/axle/hub all as one piece, rather than separate parts with adjustable tapered rollers. I have a collection of them in my shed, "sectioned" with an angle grinder, just for my education.http://fsae.com/groupee_common/emoticons/icon_wink.gif

Anyway, most bearing shops sell "automotive bearing kits". These can be either a basic double-row-sealed-angular-contact-bearing, which is very easy to fit and very reliable (much better than 2x DG bearings IMO), up to the whole assembly including wheel mounting flange. You would want the smallest of these "assy's" and then lighten it a bit more. However, they are already pretty light because the races are one-piece with the axle and housing, and you could be sure that they are strong enough (even the smallest cars are ~1 tonners these days).

Or the bearings/hubs off a Quad bike? I don't think this is "cheating" any more than buying, rather than making your own, DG ball bearings, or a buying a whole engine off-the-shelf...http://fsae.com/groupee_common/emoticons/icon_smile.gif

Z

[rjwoods77]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by SnailRacer:
We ran splined axles all the way around in 05, but used the micro-sprint splined bearing sleeves and a pair of 6910 bearings (50x72x12), which were more than adequate. For your app I'd give an extra 10 mm and go for the 6909's (45x68x12), which steps up to 3400/2530 lb load ratings. 1300/600 is a bit small in my mind. </div></BLOCKQUOTE>

Do you mean 61809 and 61909? I was looking through the skf catalog and that was the only reference numbers matching the dimensions you said. As far as expense I can get them for free. The current 50x80x32 double row bearings i get cost 50 bucks a piece.

[SnailRacer]

Nope, I mean 6910 and 6909 -- these were numbers from NTN. I dunno, I could be smokin somethin though...

[Denny Trimble]

As far as I know, 618xx and 68xx are interchangeable.

[rjwoods77]

Checked prices today. Average of a few houses.
These are with seals.
61809:45x58x7 = 147
61909:45x68x12 = 147
16009:45x75x10 = 40
6009: 45x75x16 = 42
??????: 80x50x32 = 45 bucks.

I think i just answered my own question. Packaging and cost.

http://www.hyperracing.com/browse.asp?id=830&classid=4&catid=320 (http://www.hyperracing.com/browse.asp?id=830&amp;classid=4&amp;catid=320)

[Z]

Rob,

That double-row-angular-contact bearing on the HyperRacing site looks like the "automotive bearing" kits that most suppliers carry. (Edit: Actually it just looks like a pair of 6010's (DG) or 7010's (AC)??) But I've never seen them with a 50mm ID on a production car! Maybe if you're doing an aluminium axle?

The sealed, ang.contact, auto bearing kits I've seen are ~30IDx68ODx45W, up to ~45x85x45 (on big cars!). What makes these good is that they are made so that when they are clamped up they have just the right amount of pre-load on the balls. Trying to get the right pre-load on normal DG bearings is tricky. The outer race spacer (in the upright) should be a bit(???) wider than the inner race spacer. Ang. contact bearings also have more balls in a given size bearing than the deep-grooved type, so can carry more load.

Z