I have made an animation which is showing an array of magnets which rotates around inside a magnetic field.
There are two grey parts in there too. These are iron tubes/shields where the magnets can "hide" and do its polarity swap without interference of the magnetic field outside. The swap are in reality done gradually by rotating the magnets. All magnets are "trapped" by guides all the way. These guides are twisting 180 degrees inside each shield, which each of the magnets follows.
It is only outside the shield, the magnets are repelled or attracted by the bigger stator magnets.
I have simulated the cross section of the polarity swap in FEMM with and without the shield. It requires lots of energy to swap polarity without the shield, and no energy WITH the shield.
This means it will not take energy to change the magnets from attraction mode to repelling mode, and vica versa.
Take a close look at it if you want, and comment, question, anything are welcome :)
Further simulation of the model above shows promising results. There are lots of torque in the same direction during the swap period inside the shield :)
As it doesnt take energy to swap the polarity as long the magnets are inside the shield (What I found in another simulation), the math should be a proof of a working design :)
Vidar
Quote
All magnets are "trapped" by guides all the way. These guides are twisting 180 degrees inside each shield, which each of the magnets follows.
That is a good idea.
The problem I see is to maintain those magnets in line to enter the magnetic shield while circulating around.
Jesus
Hi Vidar .....are you saying as the central magnets enter and are traveling through the steel shields ,they rotate,.....thereby reversing polarity as they exist the steel shields.....if this is correct...........how would this be accomplished?.....shylo........btw the steel sheilds would have to be thick enough to absorb all the magnetic flux from the central and external magnetic fields....so as not to interact with the magnets within the shield themselves......just questions I have not trying to be rude........thanx ....shylo
1. The rotating magnets are locked in position by a track - much like a rollercoaster. 2. The shield must be big enough. No problem. This is both engineering issues which should be possible to solve with relatively small amount of engineering skills. Thanks for your feedback:)
Quote from: nievesoliveras on November 25, 2010, 08:36:37 PM
That is a good idea.
The problem I see is to maintain those magnets in line to enter the magnetic shield while circulating around.
Jesus
As a start it should be absolutely possible to use fewer rotor magnets, 1, 2, 3, 4, 5 or so. They will behave separately in the same way as if there was an array with a bunch of magnets. What I mean is, if it works with 1 magnet, it will work with more magnets, even an array. It wil also work with only the the stator magnet in the middle (if it works with all stator magnets in place)
Vidar
Here are an alternative way of making this motor. The main key here is to shield the polarity swap of the rotor magnets, so no energy are lost during this process.
In general this motor work as an electric motor which do swap magnetic polarity due to the alternating current. However this design does this mechanicly.
I have put my name on the drawings, just in case this motor work for real 8)
I do hope more of you understands how I want this motor to work. So hopefully someone would assist, question, and even bust the design by telling straight out the "evil" truth. I really, honestly, cannot find the flaw of the design (Except "it should not work", "bending physics", "violate laws", etc.). If you guys can see the flaw (except violating laws of physics), please tell me, and explain where the mistake are made.
I have called this motor "SWAP" :)
Hello
Very interesting project. At first I cannot find out why it should not work.
On the other hand please try to explain me the difference to my NoSwap design. If you change the polarity of your stator instead of turning the rotor magnets.
In the NoSwap design, if the rotor magnets are on top, I would expect a very strong backforce, impossible to allow a full turn?
Thanks
cubalibre
that last pic will come to rest with the first ,~2 mags near polarity switch...........shylo........Vidar I like the idea of a shield...the only problem I have is the shield being saturated ? what type of material could this be made from.....shylo
Quote from: cubalibre on November 28, 2010, 05:23:17 PM
Hello
Very interesting project. At first I cannot find out why it should not work.
On the other hand please try to explain me the difference to my NoSwap design. If you change the polarity of your stator instead of turning the rotor magnets.
In the NoSwap design, if the rotor magnets are on top, I would expect a very strong backforce, impossible to allow a full turn?
Thanks
cubalibre
I have been thinking of this scenario you were drawing. My "logic" tells me that this particular design, with all fixed magnet polarity, will definitely not work. I was rather thinking of a virtually rotating magnetic field, but still rotating the mass. The array in the animation was done simple because I hadn't time to make all magnets in one complete round (My wife was yelling at me "come to bed ASAP - I'm TIRED!"). So the anmation only shows the principle of operation inside the shield.
My idea are based on having a center magnet with polarity horizontally aligned, and stator polarity aligned vertically. There will be a torque in the rotor magnet as long it stays horizontally, but rotating that magnet would eventually ended up in-line with the polarity of the stator magnet, and ends there without further motion. If we devide up this rotor magnet in many smaller ones, and let them in total feel the same torque, they would be forced to go in-line with the stator field. But what happens is that when every time one small magnet goes into the shield (half way of one stator magnet), it flips 180 degrees so it can exit in repelling mode - as all the other following magnets now are all the way 180 degrees - to the next shield where the polarity again flips 180 degrees.
Simulations shows that there is a great torque in the array, and it also shows there is not energy required to flip the magnets one by one 180 degrees as they pass through the shield.
HOWEVER! If the shield isn't there, it will require great amount of energy to swap polarity - just as much as the energy supplied by the rotor array magnets in its whole.
So what I have found is that without the small shields, the motor will not work. The shields are the only reason why it doesn't require energy to swap the polarity.
Ofcourse, I cannot claim any overunity yet. There is most probably something that isn't working in practice. So I have decided to build a simple prototype. If I manage to make one, I will show it to you on my Youtube channel - working or not.
Vidar
Quote from: shylo on November 28, 2010, 05:48:03 PM
that last pic will come to rest with the first ,~2 mags near polarity switch...........shylo........Vidar I like the idea of a shield...the only problem I have is the shield being saturated ? what type of material could this be made from.....shylo
The shield might be made double layered so the magnetic field doesn't "see" each other. Stauration might be a problem, but then I add more shield or use weaker magnets.
EDIT: Saturation in this design shouldn't be a problem. The shield can be saturated untill a sertain point, but more saturation than that would finally make the shields "transparent" and it wouldn't work at all.
Vidar
using the shield creates drag,...making it thicker or heavier will bring it to a stop ,..as will weaker magnets.........."double layered".....this prevents poles from seeing each other??...........shylo
Quote from: shylo on November 28, 2010, 06:22:51 PM
using the shield creates drag,...making it thicker or heavier will bring it to a stop ,..as will weaker magnets.........."double layered".....this prevents poles from seeing each other??...........shylo
Drag? Eddy currents? Use ferromagnetic material that isn't conductive.
Example of fields between stators and rotor which doesnt see eachother below.
I could be wrong but I have'nt found anything yet that will block magnetic attraction.........is there such a process??....shylo
Low-Q,
If you do decide to build this keep us informed. Here is the thing; Let say you
have a curved groove or track inside the shield that rotates through 180 degrees
to flip the magnets. You are going to need to accelerate the rotational momentum
of each magnet segment and the faster you rotate the magnet the more cam force
is going to be required. So it makes sense to rotate slowly throughout the entire
length of the shield, as well as have the shield be as long as possible consistent
with operation. That momentum energy is going to wasted to some extent as friction.
The motor is going to have flipping friction going on almost continuously on a bunch
of segments at once, when it is running - that it what I would worry about.
:S:MarkSCoffman
Quote from: shylo on November 28, 2010, 06:50:55 PM
I could be wrong but I have'nt found anything yet that will block magnetic attraction.........is there such a process??....shylo
You are right about this. There is no such thing which will block magnetism. But guiding the magnetism so it doesn't influence on other objects near by, is possible. That is what the magnetic shielding are suppose to do.
I have a feeling of the outcome of this design, but what I do know for sure is when energy are required to flip a magnet from attraction to repel (180 degrees flip), this energy corresponds to the energy which is provided by the rest of the system - so they cancels out to nothing. The shield in my simulations, as the picture above shows, is that the flipping magnets can do its trick without need of energy input (Which would be required due to possible counterforce from another magnetic field).
We also know it requires energy to pass a sticky spot, but if the magnetic field never pass the sticky spot, only the mass in the magnets, I have a strange feeling it will work.
If we isolate the shield together with the rotor magnets, the magnets will attract the shield in both ends even if the polarity are swapped during the operation, and cancel out the force needed to go completely through the shield. If we now put back the stator magnets, there will be a general attraction between rotormagnets and statormagnets on one side, and a general repelling force between them on the other side. Those forces will still be present no matter if the shield are present or not. The difference is that the shield will assist the polarity swap, by removing the magnetic force that prevents the magnets to flip 180 degrees. That is the only reason why I believe there will be excess torque at any time to run the motor.
Friction are energyloss which is possible to engineer more efficiently without violate the laws of physics. Creating energy out of nothing is quite much worse ;)
Experiments will eventually show the outcome, so it will be nice to test this in practice.
Vidar
The very first picture of the project. I disassambled a ribbontweeter. Lots of heavy duty neomagnets. I have one more tweeter to kill ;D
Hi...
There will be few small problems.... Magnetic field generated by small magnets inside the shielding...Changing poles inside a metal tube will affect the magnets entering the shielding... First small problem... Second...Changing poles on small magnets put new problem regarding the interaction between small magnets poles inside the shield during rotation...
What is the speed around axis and speed of the system ?...so you can calculate the minimal torque to rotate the magnets inside the shielding, knowing that the magnetic field will propagate also inside the shield (the small magnets are there, so they do have own magnetic field witch will propagate inside the shield).
This is only at first look...I did had this idea last year...little different, but almost the same. Without shielding. Try with outside magnets little oval shape in the middle, not round.... (so you have bigger distance regarding the small magnets during rotation...and you dont need the shielding anymore...where as I see it, will generate problems. It will work...mine did :)...But not so pleased about..Took 1 month to build and 5 min. to destroy... Too many mechanical details and joints.
The magnets are suppose to twist along the direction of the movement. I am not most worried about this twisting operation, but what might be worth worrying about, is the energy required to enter and exit the shield. I am not yet finished with a very simple prototype I am making - just to check this particular problem out. I will just place a magnet on a rod, and enter it into a steel tube in the precense of a long stator magnet. Mid-way inside the steel tube I will twist the rod so the magnet can flip polarity. I will then feel any possible counterforce. Also I will feel any possible forces during enterance and exit of the tube, before and after the polarity swap inside the steel tube. I guess it will resist enterence, and resist exit. The stator magnet will be much longer than the tube, with same polarity in the same direction all the time.
All magnets that is behind and in front of every twisting magnets have the opposte polarity, so in theory the twist operation alone should not require energy - maybe enterance and exit will do.
I'll keep you updated :)
Hi Low,
I will tell you a small trick...try make the outside magnets (the 2 big magnets) longer..so distance at the end of them is not bigger than 10 cm...in that point you will have almost double the power, because you will have repulsion with one magnet and attraction with other. And then, I think you can get the shielding out...as long you are turning 1 magnet at a time, there will be more than 3 - 4 pushing at maximum power if the outside magnets are long enough. This is how I did...In my model I put round small magnets with holes (like small tubes) on axel and in the center with a spiral axis they was turning...without shielding. You can also try to made 3 rows of magnets, so you will have more magnets working to turn 1 or 2 magnets at a time...and anyway, turning a magnet around his own axis, if is not so big, does not use much power. I am sure it will work.
A...one more small detail...try using round magnets (as I did) like tubes... because cuboids do have a bigger magnetic field power on the side...you know, the side power of field...in round magnets the side power is way much smaller, so you can turn it easyer that cuboids. And my sugestion is to take away the shielding. If you plan to use cuboids, try shield every magnet with soft iron...this will kill a little the side magnetic field...the shielding must be with 1-2 mm bigger than the size of the magnet. In that way, magnetic fields from every magnet will close the opposite pole thru the shield and the side force will be reduced.
Aaa...and you will have one more chalange ;D
How you plan to turn the magnets ? How are you planning to hold the part that will turn the magnets ? If you already have the solution, is good...if not... I will tell you after you boil a little ;D
Quote from: marianpiti on December 01, 2010, 05:31:28 AM
A...one more small detail...try using round magnets (as I did) like tubes... because cuboids do have a bigger magnetic field power on the side...you know, the side power of field...in round magnets the side power is way much smaller, so you can turn it easyer that cuboids. And my sugestion is to take away the shielding. If you plan to use cuboids, try shield every magnet with soft iron...this will kill a little the side magnetic field...the shielding must be with 1-2 mm bigger than the size of the magnet. In that way, magnetic fields from every magnet will close the opposite pole thru the shield and the side force will be reduced.
I have lots of small round disc magnets which is magnetized through thickness. I will use them. I do not think the shape of the magnet are critical for this purpose, as a magnetic field in general will either resist or not the twist regardless of its shape. Also the magnetic foce at the edges in a square magnet are higher, as you said, this will also affect the attraction and repulsion with similar greater force before and after the shield. So basicly the shape shouldn't matter that much - in my opinion. Just an opinion :)
Another thing is that all magnets outside the shield are suppose to "power" the enterance and exit just as many times as the magnets which is attracting and repelling at any time. So the energy needed to pass through the shield would perhaps stop the rotation anyways. But this is what I want to test out in practice, just to be sure. At least, I will learn WHY it works or not :)
Vidar
Good luck Vidar! I really enjoy your ideas, they are some of the most unique and well-thought of ideas I've seen. It's also good you have an excellent grasp of the physics and can see if things will work or not. Interesting idea!
Quote from: Blainiac on December 04, 2010, 04:03:28 AM
Good luck Vidar! I really enjoy your ideas, they are some of the most unique and well-thought of ideas I've seen. It's also good you have an excellent grasp of the physics and can see if things will work or not. Interesting idea!
Thanks for those encouraging words :)
I have done some tests with one single magnet which I guided inbetween two other magnets. I split the experiments in two sections. On in attraction mode and one in repelling mode.
First experiment went like this:
The "rotormagnet" feels a pull towards the statormagnet when it is outside, feels nothing in the middle, and are pushed back when it is closing the shield.
I swapped polarity, and the opposite forces are applied.
Green arrows are the direction of the force when using one single magnet as "rotor".
EDIT: I forgot to say that it was no counterforce when I tried to rotate the magnet insode the shield. After a few attemts I finally made an easy way to rotate it without the magnet getting stucked to the walls inside the shield all the time ;D
Maybe a continous array of magnets will behave differently, as the magnetic field then will be forced from being spread in all directions around the disc magnet, into a field which is allways parallell to eachother?
Vidar