how?

(without going into a discussion that you cannot make a completely spherical ball bearing on earth due to gravity)

If I remember correctly they are ground together in a big drum full of water and grit or was that how they made marbes??

behold -

http://science.howstuffworks.com/question513.htm


[Edited on 4/2/08 by Mr Whippy]

So they are not made by Chinese orphans using tiny chisels?

Fascinating stuff, when I worked in the foundry we used to make nickel shot for the plating industry and it was made by melting the nickel and pouring it into a pool of water. Obviously the size of the shot was very random but they were always very round. We also made anodes which had to be polished in a drum which was filled with gravel and left to turn slowly overnight and eventually all the pebbles turned into perfect spheres before they ground to dust.

[Edited on 4/2/08 by Peteff]

quote:

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Originally posted by 02GF74
So they are not made by Chinese orphans using tiny chisels?

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quote:

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Originally posted by 02GF74
So they are not made by Chinese orphans using tiny chisels?

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I was watching a documentary last night about new bridges being built in china, around 50 in all.

They where going on about how the workers were keen to climb way up high fitting suspension bridge cables due to the high wages;

$200 a month! if that's high what's low????

[Edited on 4/2/08 by Mr Whippy]

Our sister plant make the balls for NSK RHP & ISKRA bearings here in sunny Gods allotment.

Molten metal is drop down a tower through a sieve with holes graded for the size of ball required into cold water, resulting in a perfect sphere.

OR... believe it or not the most common method is on a lathe. Turned with curved tip.

Simple enough to knock millions of them out every day.

And to size the finished article they measure the noise of the bearings with a stethoscope. The less noise the higher the grade of bearing. I kid you not.

Steve

Here's a clue...

LINKY

I remember looking this up a few years back when we tendered for a job at a "former ball bearing factory". At the time we had many suggestions including filing from a block! Now that's craftsmanship!

Devid Jenkins' link is right.

They are sheared and stamped from wire/bar by a rotary head stamp/shear and then put through rill plates.

Taper roller bearing rollers are also stamped from wire. basically a cleverly arranged drive allows a head to rotate at high speed but not in a continuous motion but a series of "jerks".

At each "jerk" the wire is advanced, then sheared off by a rotating shear, then punched into a tungsten carbide die (again on the rotating bit of the machine) then punched out by an ejector pin. The whole lot happens so fast that the head just appears to be rotating and ejecting a continous stream of rollers. The die is replaced regularly and the stamp and ejector pins are too.

After forming the rollers are generally moved around in plastic tubes, that are used to feed them continously into the grinding and polishing machines and the assembly machines.

PS I used to work for Timken!

quote:

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Originally posted by NS Dev
PS I used to work for Timken!

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lol were you at Duston then??

I actually worked for Ti Desford, owned by Timken in its last 8 years and we supplied Duston and Colmar etc with the steel for the races

I didn't work at Duston, I was in the Pontefract office, but used to go to Duston and Daventry regularly and often had to take customers around the plant. They were always fascinated by the roller shop, but you couldn't have a conversation in there.

I presume it is all houses now, haven't been near for a few years.

yep, all houses now.

no idea what they are doing with the old tubes site where i worked.

Too contaminated (sulphuric acid and oil) to build on it, think its being used as storage or something