Tesla Turbine Permanent Magnetic Bearing Prototype 4 - Part 2

Here we have the modular design which has double the amount of magnets of the previous design plus they are slightly bigger and stronger ring magnets.

In each housing there are 72 x 25mm OD x 16mm ID x 5mm length neodymium, N42 magnets.

I tested the equilateral triangle design and it worked okay vertically but not as expected horizontally. Too many gaps.

So this version each magnet housing has 6 x 12 magnets all in attraction to each other and facing the same way.

The second magnet housing is identical in orientation.

The shaft has 12 magnets in attraction aligned the same way as the magnets in the housing.

I've tried all sorts of combinations and orientations and this one works by far the best.

The shaft is M16 stainless steel 316 and all the fixings are too. The magnets on the shaft are wrapped in black vinyl tape to protect them whilst assembling. They have nylon washers which are 1mm bigger 26mm OD also to protect the magnets on the shaft when assembling. The vinyl tape and nylon washers protect the magnets in the housing too.

It was actually quite straightforward to assemble. A novice could do it with a bit of guidance.

The needle points are screwed into the shaft and the discs screwed into the adjusters. They are made from hardened tool steel around 60 Rockwell.

The shaft weighs around 0.9kg / 2lb.

The magnets on the shaft are tuned to sit in central alignment with the magnets in the housings. There is about 0.1 - 0.2mm end float.

You can see where the turbine housing bolts to and exhausts.

The bearing, adjusters and turbine housings are aligned to the base using stainless steel 316 dowels.

This design has approx £600 worth of magnets which is still cheaper than a pair of off the shelf air thrust bearings, which also need a 0.1 micron filtration system and a compressor.

Nikola Tesla states in US Patent 1,061,206:

"If the runner be allowed to turn freely, in nearly frictionless bearings, its rim will attain a speed closely approximating the maximum of that of the adjacent fluid and the spiral path of the particles will be comparatively long, consisting of many almost circular turns."

I would say these bearings are the closest thing I've seen to "nearly frictionless" with no input power.

The shaft is not balanced, there is no rotor and there are no anti vibration pads fitted. All of these will increase the performance.

I make a very small modification in part 3 and it becomes even better.

Stay tuned!

[britttullos]

I would suggest instead of a needle point, possibly using a ball bearing setup identical to tip of a ballpoint pen. But instead of ink surrounding the ball, use oil.

[merlinlive]

Very nice engineering! Why not use a ceramic bearing rated at say 75, 000 rpm? Seems easier?

[MarioAbbruscato]

Awesome!
So air bearing was a bad idea ? Waiting for run the turbine . Good Job!

[petermiddleton]

That should do the job very nicely, awesome work! :) (y)

[RichardAndrade-fu]

It’s the points bro they are causing the friction for it slowing