The Natural Philosopher wrote:
On Tue, 29 Nov 2005 22:45:15 GMT, Roger wrote:

With hub mounted electric motors recovery of any waste heat would be a
problem and unsprung weight is traditionally considered undesirable so
why are hub motors the obvious choice?

They aren't that heavy. I am not decided as to whether they are better or
worse.

To an extend its possible to integrate them with the wheel rims. IN a
typical multipole 3 phase motor the magnets are arranged inside a drum
whilst the stator comprises a bunch of interlinked coils. The chief weight
is the magnets on the rim, and the actual ironwork of the stator.

This is a simple arrangement..and easily allows one motor per wheel which
provides excellent traction..whether or not a more complce and heavy system
with a centrally mounted motor and shafts and maybe a reduction gear -
probably more efficient in terms of the motor - is worth the added weight
and complexity - is a moot point.

Motors in the wheels mean considerable unsprung weight in the wheels.
This in turn means much poorer road holding. Its fine for city buses,
but used as a general runaround youre going to sacrifice a good bit of
road handling ability. It'll be like going from a car to a commercial
in terms of handling / roadholding.

Not that thats really a big problem, but public perception might be,
after being used to cars of such high performance today. People will
need to go back to the once universal ways of driving cars to their
limits at normal travel speeds much of the time. Those without the
brain to do that, and there are certainly some, will come acropper from
their failure, so in short, poorer handling equals lower safety levels
and higher death rates specific to your new design.


NT