Actually, I think it's fairly easy to build an induction motor into the
turbopump to directly drive the impeller, that way it's cooled by the
propellant flow- and never, ever going to overheat. Doing that kind of
thing seems to be far inside the state of the art for induction motors.
On 2 September 2015 at 14:53, Peter Fairbrother <zenadsl6186@xxxxxxxxx>
wrote:
On 02/09/15 12:13, James Fackert wrote:
Dyson battery vac... 100,000 rpm brushless motor driving turbo like
radaxial blower? Maybe in the 1 horsepower range run conservatively
with long life?
Maybe...
Some problems - first, it's only about 200W normal, 330W at boost, which
isn't really enough to be useful.
Second, the design is such that the integral fan is necessary for cooling,
especially for the IRFH 7932 MOSFETS, which are surface-mounted and which
do not have heat sinks.
I suppose you could get around that, but the rotor is tiny, about 7.5mm
dia by 8mm long - I haven't tried, but I don't think that it would last
more than a few seconds at useful power before getting too hot for the
magnets, unless some sort of cooling was used.
Incidentally, this raises a point about flight electric motors which I
don't think has been mentioned before - in vacuum they will overheat.
-- Peter Fairbrother
