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Electromagnetic radial engine

  1. Dec 6, 2003 #1
    Is anyone intrested in putting my electromagnetic radial piston engine theory to an educated stop?
  2. jcsd
  3. Dec 7, 2003 #2


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    What's your electromagnetic radial piston engine theory ? :wink:
  4. Dec 15, 2003 #3
    The piston/cylinder is almost exactly like a speaker drive system. The contacts at the top and bottom of the cylinder would have +/- leads which would complete the current for a strong, split secound burst of energy. This would be like conecting a speakers + to your spark plug wire and - to ground.
    Obviously using a small coil from a speaker would give you a one time blast and a blown speaker. But using a larger winding capably of handling such a large burst of energy coupled to a much stronger fixed magnet should in theory create some controlable power.

    The fact that this engine relies on spark plug type bursts
    of energy instead of continous draw is what makes this theory intresting. When your charging system dies in your car your engine runs longer then even your dome light.
    To me meaning burst type electrical power is more efficient than constant draw.
    I am starting to think maybe a cylinder much like a hydraulic ram design with two drive windings on either side with some kind of rack and pinion gear drive to turn side to side movement into rotation. Two free spin gears with the two pistons connected.
    This type of design shouldn't be as rev limited as the crank system correct ?
    When the pistons moved left, a tooth gear would drive one free spin gear and then when the pistons moved to the right they would drive another. Thus creating rotation.
    But how would you fit such a gear drive into an 8" cylinder?
    The caps on either end of the cylinder could take care of the flux and give the piston a slide guide.
  5. Dec 15, 2003 #4
    Here's a simple diagram.

    Attached Files:

  6. Jan 9, 2004 #5
    congrats poopah you just invented the jig saw lol
  7. Jan 10, 2004 #6


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    Greetings !

    Well, that's an interesting idea indeed, but I doudt
    it'll be hard to find similar mechanisms - used for
    a vehicle's propulsion (as yours is supposed to, I presume).
    There are multiple patents for such things for various

    Basicly it's the same as the locking mechanism in
    your car's doors. Of course, this one will have to
    be much more massive. I'm not sure why you think that
    short pulses will work better, but I suppose they'll
    have to work for this thing to work as a vehicle engine.

    I'm no expert. However, a couple of comments :
    1. The use of such an EM engine would require a complex
    power conversion system that would probably make the whole
    thing too costly.
    2. Vehicles today use chemical fuels - thus you would
    still need the chemical engine to produce the power
    and then loose a significant amount of it while converting
    it to be used by your EM propulsion system. An awful
    waste by all standards and in all aspects.

    Sorry. :wink:

    Peace and long life.
  8. Mar 26, 2004 #7
    http://www.eng-tips.com/viewthread.cfm?SQID=80760&SPID=931&page=1 [Broken]
    Last edited by a moderator: May 1, 2017
  9. Mar 26, 2004 #8


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    Look at the No or efficiency of a speaker (you can calculate it from the Thiele-Small parameters) and its typically under 1%. An electrical motor can reach 90% without much effort.

    The engine running longer than a dome light? Not even on my 1971 Chevy. You still need to charge the coil through the points and resistance wire and a little 157 sized light bulb is going to win. Sorry.

    A pulsed electrical discharge is already used for motor drives, its called PWM or Pulse Width Modulation. Each pulse is at full voltage but because of the inductance of the coils the average current is effectively controlled by the width of those pulses.

    The linear electric motor like a speaker uses has its advantages, namely light weight. The light weight is important and is why its used in the first place since it needs to change directions very rapidly. Adding other mechanical devices to it hurts this very valuable quality and reduces efficiency further. When motor weight isn't as important like for subwoofers, look up the servo-drive technologies being used and you'll see rotational motors used to move diaphrams back and forth.

    Your best bet for an application would be small-scale (like smaller than a RC car where the permanent magnet motor will be your competition) so you could take advantage of the light weight attributes.

  10. Dec 27, 2007 #9
    Interesting...but practical?

    What's interesting is that some of these servo type drives magnetically float the piston so you could do away with a lot of friction, but then you negate those gains by converting the motion into rotation with a gear drive. Then you've got to constanly fight the momentum of these pistons going back and forth so you'll need a massive flywheel/harmonizing system, or many more cylinders = much friction, high weight, too many moving parts. Now, take your drive shaft into the vehicle, connect some magnets to it in a circle and use your short pulses as these magnets approach points around them. One moving part, low drag, short pulses, high torque. Now just figure out where your elecricity is coming from and try to make that low weight.
  11. Dec 27, 2007 #10


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    Welcome to PF, Poopar. Your link didn't work for me.
    Anyhow, it's nice to see that you actually put some serious thought into your idea instead of just posting some crackpot scheme with no science behind it as so many others have done.
    I do, however, agree with the others that you'd be hard-pressed to get near the efficiency of a regular electric rotating motor with a reciprocal design. Keep up with the ideas though; you show promise.
  12. Dec 27, 2007 #11
    I think it is very interesting, although i ve read it and do not test it can work or not. But Can you contact me ? because I am thinking about this kind of mechanism for space vehicles and I have some ideas to discuss.
  13. Feb 8, 2011 #12
    im workin on a completely different concept. and i need to kno how an electromagnetic piston would work and the stats ,force ,volt, etc.. i need for it to compress air at about 10 psi.. assumin the piston sorface dia to be 3".. i want to kno wat would be the voltage reqired to do the work.. stroke of 3" as well. rough figures.. tnx
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