Space between ball bearings?

[Gillbot]

AFAIK bearing races are not as hard as the balls themselves. For all intents and purposes, ball bearings just can't be worn...they'll break before they change diameter. But races can wear.

The race is still damned hard, though.

No. Just No.

 

[phucheneh]

No. Just No.

Go away. Just go away.

You contribute nothing and are a troll.

 

[WHAMPOM]

Ok, so I'm building a tail vise for my workbench.
Instead of purchasing factory made thrust bearings or bronze washers, I cheaped out and bought a bag of 6mm diameter SS ball bearings.

These will be sandwiched between two SS washers, and held in place by copper and steel sleeves:

Marine grease will be added during final assembly.

Is there a rule of thumb for how much of a gap needs to be around each individual ball to prevent binding? Is this amount different for the space between bearings and space between the ring of bearings and each wall?

Error correction: The maximum orbit would have a gap of 4.24 mm (radius) between the bearings and the inner ring and 0 clearance between bearings and the outer ring (if you used all 16.6 bearings).

A middle orbit would have 14.39 bearings. (Formula (using radians) for finding # of bearings: X = pi/(arcsin(r2/r1)) where X = # bearings, r2 = bearing radius, r1 = orbit radius)

I'm thinking I need to use something close to the minimum orbit so that the bearings remain centered around the axis. Or else I'll need an additional inner spacer ring to keep the bearings centered.

I think you are over engineering this, unless you are torqueing the vise down with an eight foot cheater bar with all your weight, just grease the two washers.

 

[Gillbot]

Go away. Just go away.

You contribute nothing and are a troll.

This is purely comical.... Feel free to report my posts to the mods and if I am trolling, I'll gladly take my time off.

NOW, If you care to refute my statement, please provide some factual information to back up your claims.

ball bearings just can't be worn...they'll break before they change diameter. But races can wear.

I'll then be glad to provide you with factual information as to why you are wrong.

 

[deadlyapp]

This is purely comical.... Feel free to report my posts to the mods and if I am trolling, I'll gladly take my time off.

NOW, If you care to refute my statement, please provide some factual information to back up your claims.



I'll then be glad to provide you with factual information as to why you are wrong.

I wanted to respond but I'm way too lazy to go find data.

 

[Gillbot]

I'll humor you:
http://en.wikipedia.org/wiki/Rolling-element_bearing

There are three usual limits to the lifetime or load capacity of a bearing: abrasion, fatigue and pressure-induced welding. Abrasion occurs when the surface is eroded by hard contaminants scraping at the bearing materials.

Yes, the rolling elements are harder than the races. However, typically ALL components can and will wear.

Furthermore, if you care to read:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19830018943_1983018943.pdf

Bearings will deform under load, even during normal operation. When deformation under high load becomes severe, you get spalling. http://en.wikipedia.org/wiki/Spall

Mechanical spalling occurs at high stress contact points, for example, in a ball bearing. Spalling occurs in preference to brinelling where the maximal shear stress occurs not at the surface, but just below, shearing the spall off.

If you have mild spalling (which is still "wear") the bearing can still function but it's geometry has been altered.

Edit: Simply stating a rolling element will just break before changing diameter is pure misinformation.

 

[phucheneh]

Oh god, I feel so bad. With that 'AFAIK' in my post, you know I was putting it out there as solid, concrete fact. Specifically to challenge your metallurgical knowledge.

I mean, you could've presented your information there initially, instead of just choosing to be antagonistic for the sake of being antagonistic. But hey, that's not your style, and that's cool.

Luckily, though, according to your 'OMG LOOK I ARE TEH SMART' post, it would appear that for any practical purpose, I was pretty much right, anyhow. Races are made of a softer material, and typical wear is to them, not the balls.

I would've thought you would know this, anyhow, being such an automotive god. When a sealed bearing develops play, it involves a change in tolerances that is not at all due to the ball bearings themselves.

I've probably got some old sealed bearings laying around my press. I'll find one tomorrow, remove a ball, stick it in said press, and see if we can't make a egg. I'm betting against it.

 

[Gillbot]

Oh god, I feel so bad. With that 'AFAIK' in my post, you know I was putting it out there as solid, concrete fact. Specifically to challenge your metallurgical knowledge.

I mean, you could've presented your information there initially, instead of just choosing to be antagonistic for the sake of being antagonistic. But hey, that's not your style, and that's cool.

Luckily, though, according to your 'OMG LOOK I ARE TEH SMART' post, it would appear that for any practical purpose, I was pretty much right, anyhow. Races are made of a softer material, and typical wear is to them, not the balls.

I would've thought you would know this, anyhow, being such an automotive god. When a sealed bearing develops play, it involves a change in tolerances that is not at all due to the ball bearings themselves.

I've probably got some old sealed bearings laying around my press. I'll find one tomorrow, remove a ball, stick it in said press, and see if we can't make a egg. I'm betting against it.

Instead of prefacing your post with AFAIK and guessing, you could refrain from posting at all or at least trying to provide more useful info instead of tainting it with personal bias. The insinuation that I'm an automotive god is also ironic considering YOU post more crap there than I do.

Also, deforming a rolling element into an egg proves nothing other than you are yourself trying to troll me, ironically. The hardness of the rolling elements doesn't prevent them from wearing. They will still wear, but at a much slower rate than the raceway.