, “. ~ .- ,_ . * -I ' REFERENCE- .? -BBRARY p ;A ~~~ect;~~~vol ...

d Wind Power Systems
hence, a speed-up transmission is usually
needed-unless- the! generator is a i‘bwspeed,
vet-y heavy un$ \i borrowed from an
old -Jacobs machin
signed
rotor.
to spin at t
My early machines
ternators that needed
full output. The first tra
u automotive aldrive
bought at a go-cakt shop. Chains,
sprockets and bearings ‘of all sorts are
readily available at such places o_r at tractor
and agricultural machineryshops. However,
chains tend to be ‘noisy, short-lived, and
require frequent service.
-The next transmission I tried was a 3-
inch -wide toothed belt with a 3:1 speed-up
ratio followed by a second, narrower belt
with another 3:l ratio for a 9:l total speed-
. yp. Thus 300 rpm at the rotor resulted in
2,700 rpm a-t the alternator. This transmission
worked. well. However, it is complex,
requiring careful alignment and tensioning
of the belts. Ii is also very heavy (because of
the steel pulleys) and-expensive if bought
new. The final transmission I used was a
gear box-actually an industrial speed reducer.
Jr-r a windmill we run it backwards as
a speed increaser. Such gearboxes are avail-
. able at bearing, chain, and pulley houses
under any of several brand names. They are
heavy, cheap and reIiable..‘Fest of all, you
don? need to fiddle with them, just change
the oil.
During any do-it-yourself or commercial
project, I have noticed that the participants
Automotive alternator and belt transmission used with the second experimental
rotor. SoFe transmlsslon IS usually needed to match rotor and generator rpm a