Passive Magnetic Bearing

[Aaron]

This thread is for information on PASSIVE MAGNETIC BEARINGS.
NOT active ones.

Halbach Array and other things can be posted here.

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I think this guy is speaking Russian.

YouTube - magnetic bearings ...магнитные подшипники Николаева

Is that M.Ya.Nikolayev or Dr. Mikhail Fedorovich Ostrikov?

This seems to be the most simple passive magnetic bearing system I've
seen.

The person posted this link:


I read it in english from google translator and mentions Ostrikov. That page
seems to have some plans but the explanation doesn't seem to be very
good.

[lighty]

Inventor is Nikolaev and I suspect he is the guy at the video.

At the beginning of article they say that experiments done by Mihail F. Ostrikov shows that in a magnetic field of donut magnets there is a zone where magnetic field changes it's direction (polarity most probably). BTW- I detected same things years ago by using Gaussmeter with 3-axial probe. One can even see the same effect when using simulators like CST. So if one puts something metallic in that zone where polarity is changed it will get suspended between two polarities. That zone is rather small so one can use two magnets in tracking mode but they shouldn't touch each other. In that case it seems that such neutral zone formed between magnets is stronger (look at the figure 3). It will produce equilibrium on YZ axis but not on the X axis.

He then goes to state that for that kind of arrangement one would need tremendously powerful magnets. Next he shows that by adding additional larger magnets one can also produce X axis equilibrium (in between two such assemblies). (figure 4).

Finally he explains what should be the placement of the axle in order to achieve both YZ as well as X axis equilibrium. Thus on figure 5. blue axle represented in blue colour is dielectric material which in this case is wood. Green colour represents metallic washers. I suppose what he wanted to say is that the axle is non-magnetic and washers are ferro-magnetic.

BTW- there is another video YouTube - magnetic bearing - Experiment ... магнитный подшипник - эксперимент which is rather self-explanatory which I suspect was made by a guy attempting on replication. I noticed two things on that video. First of all he used nut which is not an ideally round body (like washers are). Secondly he used only one set of magnets and it was explicitly said by inventor that it won't work properly because of disbalance of the forces on X axis. In order for washers (and thus axle) to be fully suspended in magnetic fields on YZ and on X axis one needs two assemblies as shown in illustration 5. A good thing about this video is that it shows that there is indeed a point of equilibrium.

BTW- the guy who wrote article speaks about Nikolaev as if he knew him personally and he speaks in past tense so draw your own conclusions.


I'm subscribed at Skif and I can check out what they have to say on their forums (if there is anything since this article is from 2005). BTW- I do visit Skif forums quite often since there are a number of knowledgeable guys and it gives me a good insight into Russian "scene". However using online translation is useless and you really ought to know Russian.

Now it's 2:30 AM CET and I'm off to bed.

[Aaron]

neutral zone

It seems the existence of those 2 neutral zones, points 1 and 2 in
the first diagram violate Earnshaw's theorem just like Halbach array in
circular arrangement. Or at least is a way around it.

I was wondering why that guy was using a hex nut instead of something
round.

I spent quite a bit of time in Skif/skiv? with the google translator. There
is a lot of good stuff in there.

I came across references to Ostrikov elsewhere where he demonstrated
perpetual motion with a ring magnet and 3 balls.

[broli]

I attached an illustration showing how the bearings in the video might be working. But even if it's not exactly the same the concept should still work.

[Aaron]

original

Here is the Russian article:




Содержание - Магнитные генераторы
Проекты генераторов на основе магнитного и электромагнитного полей
Магнитный подшипник Николаева

Экспериментальное подтверждение магнитного подшипника Николаева. Как выяснил недавно (из опытов к.т.н. Михаила Федоровича Острикова), в кольцевом магните есть зоны, где магнитное поле меняет направление (рис1).

рис.1

рис.3

который получается компенсацией от сложения сил выталкивания заготовки правой и левой части конструкции (рис.5)..

рис.4

[Aaron]

neutral spot location

This is the diagram with points 1 and 2 that are clearly indicated as a
"neutral" zone.



The other diagrams show that the zone is at the location where the
large ring magnet meets the 3 smaller.

[amigo]

I know this is not the exact replica of the magnetic bearing as mentioned above, but the YT related videos section had this one, and I thought it was neat since it's very easy to replicate

YouTube - Do It Yourself Magnetic Levitation! (updated)