[david85]

The Blog Wattsupwiththat had an abreviated version of this story so I looked for the original here on the New York Times website:

http://www.nytimes.com/2010/10/20/business/global/20rare.html?_r=1&hp

Not sure what to make of it just yet but it's not encouraging either.

 

[JRoque]

Just as someone in Japan comes up with almost-as-good, non-RE magnets:

http://www.eetimes.com/electronics-...develop-electric-motor-sans-rare-earth-metals

But, as discussed elsewhere on this forum, ACIM do just fine without magnets.

JR

 

[Guest]

How about fear uncertainty and doubt. I see lots of that and have seen lots of that for many decades. So what is new here? Nothing. Do not fear it is quite certain it is to cast doubt.

 

[JRP3]

This misconception that REE's are needed to build EV motors and that BLDC motors are better than ACIM's needs to come to an end. Just take a look at the power to weight of the Roadster motor. The FUDsters constantly rant about REE shortages meaning the end of the EV, not even close to the truth.

 

[PhantomPholly]

Technology available for efficient electric motors without RE materials has been around for a while. Raser Technolgies demonstrated a 100mph HUMMER 2 years ago using such technology.

 

[david85]

I suspect the intent here is to cause speculation and force the price higher.

I also agree that induction motors are likely a better solution in the long run due to simplicity, and durability.

 

[PhantomPholly]

I suspect the intent here is to cause speculation and force the price higher.

Yeah - smart on the part of the Chinese!

I also agree that induction motors are likely a better solution in the long run due to simplicity, and durability.

Yes - unless you need maximum hp/weight, there is no real need to use permanent magnet motors. In fact the Tesla uses an induction motor - something about them being able to handle higher current?

 

[JRP3]

Yes - unless you need maximum hp/weight, there is no real need to use permanent magnet motors. In fact the Tesla uses an induction motor - something about them being able to handle higher current?

At 70lbs I'm not aware of a BLDC motor with a higher power to weight ratio than the Roadster motor.

 

[david85]

Yeah - smart on the part of the Chinese!

I've said it before, and I'll say it again - don't underestimate the chinese!

Yes - unless you need maximum hp/weight, there is no real need to use permanent magnet motors. In fact the Tesla uses an induction motor - something about them being able to handle higher current?

I used to think that too. I also thought that BLDC motors have a wider efficiency range, but.....

At 70lbs I'm not aware of a BLDC motor with a higher power to weight ratio than the Roadster motor.

......now I'm not so sure anymore.

Besides, motor windings are more shock and temperature resistant than perminant magnets and could work better for wheel motors in the long term. Besides, they would be easier to service and rebuild if there weren't any super powerful magnets to eat all your steel tools! (or fingers)

 

[PhantomPholly]

Besides, motor windings are more shock and temperature resistant than perminant magnets and could work better for wheel motors in the long term. Besides, they would be easier to service and rebuild if there weren't any super powerful magnets to eat all your steel tools! (or fingers)

I am convinced that "wheel motors" are a bad idea. It places more shock on the motor, and creates more un-sprung weight and thus a poorer ride and handling.

The ideal will be a separate motor for each wheel with it's own CVT. Fully independent suspension with CV joints will give excellent ground clearance while keeping the CG low. Multiple motors and controllers means never getting stranded.

If we go "fully magnetic" we might as well have a magnetic CVT, too. I think we'll be seeing a lot more of this technology - imagine gears that never wear out and don't need lubrication?

 

[major]

I am convinced that "wheel motors" are a bad idea. It places more shock on the motor, and creates more un-sprung weight and thus a poorer ride and handling.

The ideal will be a separate motor for each wheel with it's own CVT. Fully independent suspension with CV joints will give excellent ground clearance while keeping the CG low. Multiple motors and controllers means never getting stranded.

If we go "fully magnetic" we might as well have a magnetic CVT, too. I think we'll be seeing a lot more of this technology - imagine gears that never wear out and don't need lubrication?

Hi Phant,

I agree about wheel motors. Disagree on your other two points. CVTs aren't needed. And Haven't seen anything new from Magnomatics for a year now. Maybe they figured out it was just a clutch and not a CTV Oh well, it used REE anyway.

major

 

[PhantomPholly]

Hi Phant,

I agree about wheel motors. Disagree on your other two points. CVTs aren't needed. And Haven't seen anything new from Magnomatics for a year now. Maybe they figured out it was just a clutch and not a CTV Oh well, it used REE anyway.

major

Yeah, no site updates often means bad news, but on the optimistic side just means they aren't funded well enough or disciplined enough to make meaningless announcements. I did contact them by email about 4 months ago, got a prompt responseAnyway doesn't give you that warm fuzzy that they are making progress.

Yes they used REE for weight; wonder if the principles could be built into an induction motor?

 

[JRP3]

No real need for a CVT with ACIMs, again look at the Roadster.