How Can a Rotor Have a Single Magnetic Pole on Its Outer Face?

[Salvador]

Hello, Happy New Year everyone.

I wanted to know or can anybody show me how would a rotor like that look like or how it would be wound?
I need the rotors outer part that faces the stator to have a single magnetic pole coming out of it , not like typical rotors that have poles on them and one is N and then the other one is S and so they rotate inducing varying flux in the stator but I need the rotors outer face that faces the stator to have a single magnetic pole lines coming out if it all around the outer face of the rotor.

is that even possible and what shape the windings should be placed then ?

thank you.

 

[zoki85]

I'm not familar with the term (but English is not my first language). In the past I saw unusual constructions of rotors though. I remember one where multiple permanent magnets are fixed on the rotor and all point with same polarity outwards. Could this be referred to as a "monopolar machine" too?

 

[Salvador]

I think it could yes I know such permanent magnet designs but I need electromagnet as to change polarity whne necessary. We can't make a monopole magnet but I suppose we can make a device where at a given area only a certain pole field lines exit or enter.
I need this because of the way my stator is wound , the windings are such that they for a large toroidal solenoid around the rotor , and if the rotor would have N and S poles as usual then counter currents would be produced in my stator and they would cancel out giving no net induced current.
So i am asking of such a rotor described above.

I watched a video and made a screen shot , of a rotor that looks like it could suit my device , could someone please explain how the windings are made inside the rotor as it can't be seen in the picture also what are these types of rotors called, but I assume if the current direction on all the wires running down the length of the rotor is the same then the outer face of the rotor could have the field line type i need i guess.

 

[Salvador]

the rotor in the picture reminds of the AC squirell cage rotor which comes in AC asynchronous induction motors but I guess it's not exactly so as the windings at the ends turn and probably go somewhere instead of just connect all together.

I wuld appreciate if someone showed me the magnetic field of such a rotor and the way its wound.

 

[zoki85]

Yes, the structure in the photo has a resemblence to squirell cage rotors found in big asynchronous machines.

 

[Salvador]

but squirell cage ac rotors have their conductors shorted at both rotor ends with a conducting end plate? Here I don't see that , but then again I don't see any slip rings etc either.

 

[zoki85]

I don't see that either. But I don't see other important features .Quite likely it is rotor of some big AC machine though.