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Design modifications for a dynamo, including changes to the pole, brush sizes, and carcase.


Identifier  ExFiles\Box 39\2\  Scan072
Date  1st June 1921
  
Contd. -2- EFC {E. Fowler Clarke - Electrical Engineer} 5/T1.6.21.

He considered the cross sectional area of the
pole for the previously designed machine too large and
that we should reduce this so as to get on more turns for
excitation.

The polar arc should be kept closely to 70%
of the polar pitch.

All dynamos considered by us for the present
will be of the simple single field winding third brush
control, exe(Aero Engine)mplified by the Rotax AT.12 machine.

X.3945 x 33/48 Mr. Royce fixed up two standard sizes of
brushes which we should use, the larger being 1" by 3/8" and
the smaller 3/8" by 5/16" in the cross section. He considered
that this Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) I dynamo could be provided with brushes of
the smaller standard.

The carcase of the Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) dynamo he stated
should be thinned down to .275". It was left that Mr. Elliott
would send through sketches and drawings showing the new
dimensions, after which we would send the necessary complete
electrical calculations and the expected performance of the
machine.

EFC. {E. Fowler Clarke - Electrical Engineer}
  
  
From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).


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