Stepped Gradient Magnet Motor

[SkyWatcher123]

Hi folks, had this idea to try this type of magnet motor with electromagnet assist to continue rotation cycle.
The electromagnet may only need to neutralize the rotor magnet field or repulse a bit, we will see.
The hope is, that the one rotor magnet will be smoothly attracted to the electromagnet core, while the opposite rotor magnet assists in this process.
It is still in construction, here is a pic and a cad drawing.

peace love light

[SkyWatcher123]

Hi folks, i forgot to say, any comments or questions welcome.
Has anyone built something like this or do you think it will work well.
Also, take note of the opposite rotor magnet positions, it is offset so that both rotor magnets are not sitting directly over any of the stepped stator magnets at any given moment.
peace love light

[gyulasun]

Hi SkyWatcher123,

In most of the cases in such setups,  (you surely know this),  the problem is that the increasing torque force of the rotor (gained during its travel through the gradual stator magnet steps) is still not high enough to go through the last step where the strongest attraction force exists between the rotor and stator magnets (sticky point).

While it is okay that you want to help the rotor go through the sticky point by using an electromagnet, in most of the cases it is a question whether the setup can be looped back (by utilizing the motor torque to drive a generator for instance). While you have not mentioned whether your aim is a self-runner,  it seems that an efficient motor could be built from such setups.

What I do believe a possible remedy to reduce the unwanted force at the sticky point is to apply a counter force onto the shaft by a separate rotor-stator magnet pair which should be positioned to interact with each other when the rotor blocking force at the sticky point is at a maximum. If your sticky point is an attract force, then your magnet pair should give a repel force, of course. I refer to this drawing I showed to a member to indicate this compensation method here:
http://www.overunity.com/13540/magnet-question/msg362716/#msg362716  The magnet pair (two simple rod or block magnets, one of them is fixed on the shaft, the other is fixed as a single stator magnet) should have no any magnetic flux connection with the stepped gradient magnets or with the 2 rotor magnets. Say your sticky point is at the 3 o'clock position, then the compensating magnet pair should meet in repel also at the 3 o'clock position, their facing distance should be adjusted to control the amount of the repel force between them just to compensate the attract force at the sticky point. 
I took the force "compensation" method from Bertil Werjefelt, he had showed such in one of his patent applications in 1994, Magnetic battery. ( http://www.rexresearch.com/werjefelt/werjefelt.htm )

With your setup, there can be other issues (beside the sticky point), I will return to discuss them later  (position of the electromagnet and the unwanted induction in its coil by the rotor magnets).

Nice build, just carry on.

Gyula

[SkyWatcher123]

Hi folks, Hi gyulasun, thanks for the well thought reply.
Yes, those are similar thoughts i was having when designing this, to try and counter balance the sticky spot from last stator magnet to electromagnet.
It is designed for attraction mode.
I initially made tests with 2 magnet steps in linear fashion on a board.
This to determine the gap needed between stator magnets, to prevent any unwanted static magnetic field valleys so that the rotor magnet pulled strong and continuously forward.
Then when drawing it on cad, i realized with 2 rotor magnets, the opposite magnet will help this counterbalancing of the sticky spot to some degree, though not fully as you are sharing solutions for and i am thankful for.
The intention is to have excess shaft work above what is input into the electromagnet.
peace love light

[gyulasun]

Hi SkyWatcher123,

I think you are doing fine with your 'designing hat' on.      Yes, the 2nd rotor magnet does help the 1st rotor magnet go through the sticky point but unfortunately it would still not be enough in itself (in most cases).

Regarding some other issues I hinted at, here are my additions. On the positioning of the electromagnet I mainly mean the angle of the axis of the electromagnet coil (or core) with respect to the rotor plane: to utilize the most attract force from the electromagnet, its axis ought to be as tangential as possible to the rotating plane of the rotor. Worst case is I think when the coil axle is perpendicular to the plane of the rotation of the rotor (i.e. when the shaft of the rotor and the axle of the coil is in paralell with each other), from your CAD drawing this seems to be case?

By the way, it is not a must at all to pull (by the electromagnet) the same rotor magnet which is just in the sticky point, you may consider placing two separate rotor magnets, shifted elsewhere on the rotor arm with a much favorable angle facing towards the electromagnet whereby the interacting forces can be the strongest possible between them when you fire the coil, thus utilizing the most force possible from the input power.

I mentioned the unwanted induction in the electromagnet coil:  unfortunately it will happen to be just the highest when you are to switch the coil on because of the closest position of the rotor magnet to it in those moments. And of course the induced voltage polarity by the rotor magnet will be such as to work against the input pulse voltage amplitude... i.e the difference of the two voltages will drive current in the coil.

The simplest solution to get rid of the induced voltage would be to use two soft iron pieces of about equal size to the two rotor magnets i.e. replace the rotor magnets with them. I know that motor torque would be less because "half of the attract force" would be missing from the setup but there would be no induction in the coil from the rotation. OF course this rotor magnets replacement with soft iron pieces ought to be tested, their usage strongly depends on how much  benefit may come from input power reduction versus output torque loss.

Another solution to reduce the induced voltage in the electromagnet coil is to apply the idea from member Allcanadian, see his first post in this thread at energeticforum: http://www.energeticforum.com/renewable-energy/2790-no-bemf-motor.html   I think you are a member over there too because to see the uploaded pictures you have to log in.  Nevertheless, I attached his drawing below for those reading here who are not members there. So the rotor magnets would close most of their flux across the side wall of the stator cores facing the magnets so that the coil behind the side walls receive but a small flux change versus the case with the usual cylinder core for the electromagnet.

Good luck with the build. I wonder whether you happen to have a stepper motor laying around, from defunct printers for instance, they usually make a good generator (mostly 3 phase) when their shaft is rotated and I thought of driving such stepper motor with your motor to produce electric power that could be loaded and measured easily after rectifying its output.  Unless you have Proney brake test setup of course.

Gyula