High speed induction motors

[Michael GilliganParticipant @michaelgilligan61133]

If we need the high-speed spindle to fit within a 12mm diameter drawbar, then the top bearing is going to be small.

MR117 looked promising : **LINK**

http://www.aotengbearing.com/p/nsk-miniature-bearings-mr117zz-p42898.html

… but may not leave enough wall thickness.

It would be better if we could make use of the 'Counterbore' … is it concentric ?

MichaelG.

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Edit: These are also worthy of mention: 

http://www.skf.com/uk/products/bearings-units-housings/roller-bearings/needle-roller-bearings/combined-needle-roller-bearings/index.html

Edited By Michael Gilligan on 27/01/2017 17:11:17

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Gilligan on 27/01/2017 16:51:01:

It would be better if we could make use of the 'Counterbore' … is it concentric ?

.

RM6_100 suggests that it must be …

MichaelG.

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[Mark CParticipant @markc]

A slightly different approach to getting a high speed spindle (spurred on by the idea of putting a speed increaser on and thinking about alternative "compact" power and coming up with air turbines to run in the spindle) it turns out you can buy high speed air spindles. I did not spend much time looking but try searching "air turbine tools – high speed spindle". You should find a fair few ideas with commercial products reaching at least 80k rpm. depending on cutter size, perhaps dental equipment? I have never seen one in use – most of what I do is at the other end of the scale

Mark

[EmgeeParticipant @emgee]

The original speed multiplier on the drawing used an A5 magneto bearing at the top and an A13 at the bottom of the collet spindle.

Emgee

[David JuppParticipant @davidjupp51506]

MichaelG – the counterbore at top end is only to house disc springs, so hardly a precision requirement. I don't have a part drawing for the spindle, so can't say for certain, but I'd be surprised if Denford spent special effort to ensure counterbore concentric with the BT30 socket. That bore may not even be tightly controlled on diameter.

If tackling this problem, I'd try to design to cope with the possible tolerances.

[Michael GilliganParticipant @michaelgilligan61133]

Thanks, David

Wishful thinking on my part

MichaelG.

[Author]

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