# Copper Rotor



## SandRailEV (May 11, 2012)

Salty9 said:


> Implications?
> 
> http://www.engineeringtv.com/video/Copper-in-the-Rotors-of-Motors;Society-of-Automotive-Engineers


 
It's my understanding that copper in rotors reduces losses thereby making the motor more efficient.. I believe Tesla uses copper in their rotors...


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## Ziggythewiz (May 16, 2010)

I guess I thought all rotors were typically copper. I don't know what kind he's talking about, but most don't seem to have enough mass for the material cost difference to matter much.


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## Salty9 (Jul 13, 2009)

Many induction motors use aluminum bars in rotors.


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## Nathan219 (May 18, 2010)

I can confirm the Tesla Copper rotor.


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## Tesseract (Sep 27, 2008)

Implications? Copper for the rotor bars will have lower losses (and silver lower still) but aluminum is infinitely more popular simply because it is easier to cast the bars in place with it. Copper does not form good castings and any alloying to improve the casting ability (e.g. - the bronzes and brasses) results in a much higher bulk resistivity (called ρ, or lower case rho).

The induction motor has been around for more than 100 years - there's not much new going on inside of one these days.


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## subcooledheatpump (Mar 5, 2012)

The most they do with new induction motors (in industry) is add the copper rotor and use low friction bearings. They also try to stuff as many windings into the slots as they can, but most don't use all of the available real estate. "servo" type induciton motors are usually a little more filled.

As said above, the copper rotor is more difficult to make, therefore even new induction motors mostly still use an alumnium rotor, the copper rotor is available on request or with a high efficieny motor, and you'll pay a premium

Siemens I know makes an industrial induction motor with a copper rotor, and they have for quite some time now.


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