Strongest Ball Bearings 1

[michals5]

Has anyone come across ball bearings with alternative materials or construction that are stronger than typical steel deep groove bearings?

I have been looking for something that fits these dimensions:

http://medias.schaeffler.de/medias/en!hp.ec.br.pr/60..-2Z*607-2Z;bcVdhU9y9W0-?clrsb=1

(copy and paste link)

that can handle a greater static radial load and still handle axial loads.

It's been a while and I haven't found anything.

 

[btrueblood]

Can you get a roller bearing (needle bearing) to fit?

 

[ornerynorsk]

Double row angular contact ball bearing.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[FACS]

I couldn't get into your link.

Have you looked into Aircraft quality bearings?

Charlie

http://www.facsco.com

 

[MikeHalloran]

How much stronger do you need it to be?

I don't personally care, but I want to point out that you can trade off load capacity for life, if that's an option. You have to go into the 'fine print' section of the catalog, and evaluate a bunch of equations using information that you haven't supplied us.

If you don't want to drag out the catalog, call the bearing company and ask for a Sales Engineer. They love to do that stuff. ... Okay, they may or may not love it, but they get paid to do it for you.



Mike Halloran
Pembroke Pines, FL, USA

 

[dinjin]

The contact angle on these bearing are low and primarily for radial load condition. In order to increase the contact angle you would need more material in the races ie less clearance between the inner and outer races and maybe use a thin cage
in the bearing. 4 point contact bearings i.e. gothic arch design will allow more axial loading as well but reduce the amount of static load allowed. If you supply FAG or Ina with all of your load parameters, they can answer your question. Maybe even a cross roller bearing might be possible. If you are simply asking are there stronger materials to increase the static load and keep the basic design as shown, the answer is no. If you are asking for more life the answer might be yes if you insist on cleaner and vacuum melt and vacuum degassed steels.

 

[michals5]

Thank you for your replies.

The link should work if the whole thing is copied and pasted. It works on the American version of Firefox I'm using here in Germany. Sorry I couldn't hyperlink the entire link, I tried but it gets cut off at "*".

It is a link to specs on the FAG bearing I'm currently using:
607-2Z
d 7mm
D 19mm
B 6mm
Cr 2750 N
Cro 1050 N
axial load ratings are about 50% of radial

The bearings are in slow turning mecanum wheels. As the wheels rotate the load changes from radial to axial. I'm increasing the load on the wheels and the weakest point is the bearings. The OD and width of the bearing can't be changed without changing many expensive machined parts in the wheel. Only the ID(d) can be smaller than 7mm.

A roller or needle bearing won't work because there is an axial load.

Every double row angular contact bearing I've looked at has been too wide.

I just searched aircraft quality. I recognized two of companies that came up from previous inquiries, but I'll keep looking in that direction.

Trading off the life for a higher load is a feasible option, I'll look into the fine print and equations.

20% stronger or more would be ideal.

 

[GregLocock]

Wild and crazy thought what's wrong with plain bearings (journals)?

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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

 

[dinjin]

m 0,0080 kg Mass

Cr 2750 N Basic dynamic load rating, radial

C0r 1050 N Basic static load rating, radial

nG 32000 1/min Limiting speed

nB 35000 1/min Reference speed

Cur 53 N Fatigue limit load, radial

These are catalog ratings and tell us nothing about your loads.
When you state turning are you meaning pivoting as in turning direction? Greg Locock's suggestion may be right on. How much life are you getting? The bearings are primarily radial designed bearings and not to have axial loading. Another possiblility is to remove the cage member i.e. use full number of balls and see if that will help. Your alternative is to double the wheels to
lighten the load on each bearing.

 

[michals5]

Plain bearings are a good theoretical solution, but in this application the additional friction would throw off the motor control and odometry of the four wheel platform.

Dinjin, those are all good suggestions, I'm working on life calculations and the possibility of adding balls.

The best solution I found so far involves cutting into the tires to make room for bearing that have a smaller diameter but are wider, such as these:

http://medias.ina.de/medias/de!hp.ec.br.pr/NX..-Z*NX7-Z-TV;bozcCVDWTthg

Modifying any of the other components is a last resort.

 

[Tmoose]

Did I miss the post that included your actual loads?

 

[geesamand]

First run the L10 calcs and see where you are with the current rating. SKF has a pretty easy-to-use L10 calculator on their website.

If the limiting value is dynamic life and your rotating speed is above a few hundred RPM, do an L10a calculation and you'll probably find the adjusted L10 life is a lot better.

David

 

[tbuelna]

michals5,

If all you need is a 20% increase in dynamic load capacity, then switching from a conrad bearing to a full complement bearing should get you there. Of course, a full complement ball bearing would require a loading slot or split race.

The descriptions you gave of your bearing arrangement are a bit vague. But assuming that your wheel design currently uses a pair of deep groove conrad bearings, then switching to a pair of preloaded angular contact ball bearings of equivalent cross-section would also give better load capacity. The preload improves the load distribution among the balls.

Hope that helps.
Terry

 

[dinjin]

You might also consider using an Extreme Pressure or
High Load Grease. What grease are you using?