Flat copper windings?

[Animalector]

Hey there. I was wondering if it's possible to use flat copper sheet / strap as the windings. it seems as though rather than using 18 strands, 4 turns, we could use just 4 turns of 2mm copper sheet.

Is there a reason why this is not done? what would be really cool is tapered copper to account for the motor diameter (i.e thicker on the outside thinner on the inside..)

refer picture..

 

[spinningmagnets]

There has been some work on "hairpin wound" stators. I don't know the advantages or drawbacks, but I am intrigued because this style would be very easy to add the windings to the stator laminations, meaning that the cheap hand labor of China might not be an advantage, so these "could" possibly be affordable to build in the US.

The pic is the motor from the Chevy Spark.

link about hairpin alternators http://blog.dcpowerinc.com/2013/11/01/the-truth-behind-denso-hairpin-high-output-alternators/

 

[\/ampa]

When the slots would have an even width it would be an option for high copper fill.

 

[kenkad]

I am so glad you asked that question!!!! I asked this also in context of a axial flux design because I was curious if it is possible to make the flux distribution across the length of the coil more uniform (to minimize saturation at the ends). In other words a non uniform distribution of copper across the length of the coil. A lot easier to do with flat copper foil. I actually had some coil laminations laser cut to test this. Professor retired and there were no students in that area of EE to do any kind of study. No response from FEMM companies either (Infolytica or Ansys). All I got of any technical value was that you would have to do this in the context of a set of coils so mutual inductance effects were included, etc., etc. I put all that aside two years ago and am waiting for someone like you to resolve this. I think if you lookup Shane Colton's old blogspot (MIT graduate student), he did use flat copper windings (uniform copper distribution in the coil) in one of his motor designs. Good luck and I hope you make some progress.

EDIT: Ignore this if you are looking at outrunner/inrunner types. Sorry I guess I spoke too soon.

 

[Miles]

You can buy enamelled rectangular wire of different aspect ratios.

There's a lot on using rectangular wire & fill factor from here: http://endless-sphere.com/forums/viewtopic.php?p=841458#p841458 to the end of the thread.

 

[liveforphysics]

It's so difficult to wind, don't bother if you are not expert and dedicated. I personally gave up after failure to get a single tooth without chipped enamel.

 

[flathill]

Many suppliers of flat/rectangle/square wire off two coating option. Single film or heavy duty with a second overcoat layer. Still you are not going to hand wind very thick wire. You can still wind bifilar/trifilar on up with flat magnet wire. They can lay side by side or stacked when wound in parallel. Much easier to hand wind

 

[friendly1uk]

It's a pain, but flat bar can be painted with shellac and bound like an Egyptian mummy at normal ebike voltages. It takes an ice age to complete though. I wouldn't get involved.

 

[major]

It's a pain, but flat bar can be painted with shellac and bound like an Egyptian mummy at normal ebike voltages. ...

I've seen some places using kapton tape instead of the mummy method. I think some transformers are wound with foil conductor, but I have not seen it in a motor. End connections would be a bitch. And you also need to consider added capacitance if you use high frequency PWM.

 

[Animalector]

the question was just a mental blurt.. I was originally thinking why we couldn't leverage off very cheap PCB printing process to make our lives easier for preparing coils or interconnecting coils of flat copper at the ends.. But there are surely better minds than mine working in industry on this problem for companies like Tesla, and the major car manufacturers.

oh well..

Andy

 

[Doctorbass]

When a cromotor with flat winding will be produced?...! lol

When these good chineese girls at the manufacture will be paid better i guess!

Doc