Hubless Motor

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Hubless Motor

A page for the collection of information concerning this project and the coordination of the build.

Underlying Principles

This project is based on the same principles as a Mag-Lev train except wrapped into a circle:

Project Information

A really good write-up about Penn State Harrisburgh's project:

Project Discussion Transcript (the conversation that started it all 08/05/2010)

Bradley: how much experience do you have with linear motors? me: do you mean motors that produce linear motion or actual linear motors? Bradley: linear motors me: I have read about them


that's like the maglev principle, right? Bradley: kinda, the maglev works with the idea the linear motor is the propulsion same prinicpal as a rotary motor but applied in a straight line I plan to use it in a car hubless maglev design as in the vehicle has no contact with the wheels and is held up my magnetic force me: that sounds fascinating Bradley: doesn't it me: yes, it does I would be willing to help that sounds like a blast Bradley: I hoped you say that I want to build some prototypes and see how well it works me: yeah, nice Bradley: then throw it on to bike based power wheels me: you'll have to explain the physical principles sometime in person Bradley: think mag lev train me: yeah, except with wheels that don't touch Bradley: the wheels take the place of the track it's a vertically circular track if you will me: haha, I just need to see some flux lines, that's all ok, so the rotation mechanism is similar to that of a stepper motor? so is the inside of the wheel lined with opposing magnetic fields? Bradley: yeah me: I wonder how that will hold up under load Bradley: magnetic force is more powerful then gravity but yeah I want to see that too like can it handle 300 lbs I think neodymium magnets can easily handle that me: the car + a rider? Bradley: yeah me: conceivably this should be more efficient than a standard motor Bradley: yeah no friction me: like a brushless motor Bradley: exactly me: You know what, we may need to include some sort of rolling element to hold everything in place Bradley: rolling element? me: well, ideally the outer rim would never touch the inner rim Bradley: yeah me: and would "levitate" on the magnetic fields Bradley: yes me: I guess we'll find out as we prototype, but I was reading that tolerances have to be really tight so if we needed to we could use Mag fields for propulsion and a bearing for suspension Also: Bradley: yeah there are companies that sell magnets in quantities of 100-500 I think we would be looking at those me: true Bradley: and a little flatter me: so true Bradley: but I'm going to look into engineering texts on maglev trains and such I'm guessing they are using eletro magnets or even super conductors also there are low speed designs and high speed designs of linear motors me: well, the control magnets have to be electro-magnets (obviously) Bradley: yeah me: I know that maglev trains' active component is a liquid nitrogen/helium cooled superconducting magnet on the track Bradley: hmmm LN2 on a power wheels me: the level of coordination required for a bullet train's magnet systems is scary haha, it depends on the superconductor, now you may be able to do it with liquid helium they are getting closer and closer to room temperature but they aren't there yet I studied this in Materials Science Bradley: closest I got was physics 2 and parts of quantum mechanics me: close enough anyway, I don't know if we can sustain electromagnets on low power for the levitation part Bradley: oh and lots of empirical science in highschool engineering I need to study magnetism again do they require high voltage? me: not necessarily Bradley: lots of current? me: the magnetic field is proportional to the current I just had a thought about the positioning of the levitation magnets for some reason, I am thinking we'll need an odd number of magnets on the outer rim and an even on the inner rim so there's not really a low equilibrium position are you going to be at the space tonight? Bradley: nope I'm going to chicago I'll be back in the space next week me: ok, I am going out of town Friday-Sunday we'll coordinate Bradley: ok me: I don't know if you read this article, it looks very good: Oooh! We can implement a sort of regenerative braking (maybe) do we have a wiki-space for this project? Bradley: not yet go ahead and make one me: will do Bradley: though I am curious as to what kind of magnets they used. I'm assuming they used those cheap magnet strips me: the article says it uses magnetic strips but it doesn't state what kind or what strength Bradley: yeah, that makes my mind think craft store supply magnets that come in rolls I'm assuming the bulk of their cost came from the fact they used high grade aluminum and the machining on those hubs looks professionally done on a lathe or a water jet cutter I'm thinking the heavy duty ones will work me: I wonder if we could embed square magnets into the frame of the wheel with good results it seems to me that most magnetic strips are rather weak Bradley: I was thinking of gluing them for a working protype me: right Bradley: and using kids bike wheels we can remove the spokes and hub once we are satisfied that it will work me: I am going to copy and paste this conversation into the wiki for future reference