Re: gearing ratios

[Stephen Barnes <steve@spbarnes.demon.co.uk>]

Robert McDonald wrote:
> 
> Peter VanDerWal wrote:
> 
> > I've seen small brushed motors designed for model airplanes that spin at
> > +15,000 RPMs.  I think some of the traction motors spin at up to 6,000-8,000
> > rpm.
> 
> So the faster they can spin the better they would be for a single speed EV?  Or
> do other characteristics suffer as a result of their ability to run at high
> speeds?
> 
> > I've heard of brushless motors running in a vacuum with magnetic bearings
> > running at over 100,000 rpms.
> 
>   That's how they make those flywheel things isn't it...(?)
> Rob.

I could show you tomorrow a ball bearing motor capable of 50kW at 60,000
rpm and able to take up to about 90,000 rpm. It wouldn't be too much use
in an EV though due to the size of gearbox required, and a controller
the size of a coffin (probably).

Steve