Alternative thrust bearings

[sch]

3phase: Those are what I used, sourced locally from Motion Industries and IIRC were INA brand. I don't think Motion sells junk.
The top washer cracked and two pieces broke off one about 6mm, other 3x12mm and I suspect these broken pieces chewed up the needle bearing. AFAIK they were clean and well lubed. From your figures, it should have been ok. Hmmm.... More head scratching, at least they are cheap. I can't imagine heat being a problem in 1-2minutes operation at 10-20rpm. The washers are ground and sold with the bearings.
Steve
Steve

[Leigh]

Steve,

I've used the same bearings that Adrian showed, made by INA, with no problems at higher loads and speeds. They're quire good. Were your bearing surfaces parallel?

------------------
Leigh W3NLB

[uute]

How bout support behind the washers, were they just riding on a flange orount the ID, or supported full width of washer (to OD)?

[3 Phase Lightbulb]

Maybe you grabbed the wrong can? Do you keep your valve grinding compound next to your can of bearing grease?

[Peter S]

Wherever possible I would use a normal single row radial ball bearing. This may not been in the design books, but...

they are cheap, readily available, will do the job and especially because they are SEALED.

Taper rollers, needle rollers, plain bearings etc all have the same problem - how to keep them clean (plus comparitively expensive).

No doubt you will say that this is a thrust situation, but (from memory) a radial ball bearing will handle about 1/3rd of its load as thrust (correct me if I am wrong).

And this is only about 300 lbs, so a 7/8" bore bearing should be fine.

Also, though a bit bulkier, the self aligning type of bearing is worth considering - these are made for conveyors and the like, they are a housing and bearing combined, ideal when things aren't quite lined-up! (Which is a possible reason for the problems).

The cheapest type have pressed steel housings, the heavier type use a cast iron housing. Available in flange mount style for this sort of application.

Any comments or criticism?

[mbensema]

The bearings are certainly not junk, INA makes very high quality bearings, and I'm not saying that because they sign my paychecks.

Those bearings are meant to be used along with a radial bearing unless you have some way of preventing radial loads on the bearing. The type of load you have needs radial support as well as the axial. You will have a load on the sprocket that will try and shift it out of alignment and that will put a very high concentrated load on the bearing. Use the tapered roller bearing or angular contact and you probably will not have any problems.

[mbensema]

Sorry, I mispoke, didn't pay attention to what I wrote.

[This message has been edited by mbensema (edited 02-03-2006).]

[sch]

The concentrated load theory is a good possibilty. I will have to look carefully at the setup again and see if I can find washers a bit more substantial than 0.032"
Thanks.
Steve

[sauer38h]

<font face="Verdana, Arial" size="2">Originally posted by mbensema:
deep groove ball bearings can only handle an axial load when there is a radial load also. </font>

Huh?

[J Tiers]

<font face="Verdana, Arial" size="2">Originally posted by mbensema:
Peter,
deep groove ball bearings can only handle an axial load when there is a radial load also. </font>

Eh? They do fine, within ratings, which is the key.

As far as the thrust bearings, Possibly you didn't support them. If you don't, or the support is rough with that thin washer, they will flex themselves to death. They want a smooth flat race to run in, and no radial load. You have to back up the washers.

I think the taper roller bearing is perfect here. Does both location and load support. The 300 lb is nothing.

Bearings take load depending on the speed and teh number of total turns you want. The million turn rating of the angular contact 60mm BALL bearings in my Logan is 4 tons axial.

At 300 lb and low speed it would last half of forever. The roller will last 3/4 of forever....