Thanks for your email and I did look up the archives on keely net which
made me querie.
The textbook from the 1920's goes into very fine detail about how to
construct d.c. motorgenerators and fortunately in this country there are a
lot of people hoarding ancient motors in private museum collections. A 35
horsepower motor as stated is quite large in diameter. I will have to study
the instruction and drawings as to how many poles, commutators construction
as all motors in those days but for the experimental induction motors had
commutators and brushes.
I immediately thought of the sparking of the brushes throwing up a back lash
at compound frequencies. (Adams motors) Also the motors were the same as
the generators and could be used to drive or be driven so if the motor was
rewound in an 8 pole configuration it could possibly be configured to
excite the primaries of the quoted ELECTROMAGNETS (cast iron cores) on the
in between phase by off setting the commutators which was done by means of
a special handwheel to prevent arcing. My textbook quotes the 4 pole
configuration to be the norm. It was most probably a d.c. motor driven by
pulsed d.c not a.c.Also a 4 pole configuration could be rewound to be half
driving and half generating by means of the 8 coils around the central core
which would probably be in series with the primaries of the 8 electromagnets.
I would have to be convinced of the current produced from a single winding
over possibly a 6 inch diameter central core.
I hazard a guess and state that the mass of the inner core would be made
identical to the mass of the 8 cores around the outside to provide a
balance pulsing between the two masses.
However, I await the comments from others as there may be an electrical
genius amongst us who is a motor winder.
Greetings from down under
Ren