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).
Providing criticisms and notes on the design of a U.S.A. Phantom Generator.
| Identifier | ExFiles\Box 43\1\ Scan022 | |
| Date | 30th September 1927 | |
| X398T To OY. from EFC. c. BY.{R.W. Bailey - Chief Engineer} EFC6/T30.9.27. RE U.S.A. PHANTOM GENERATOR. X8671 Regarding the group of prints which you sent over in connection with your generator and cutout, to Proposal Sheet No.76, under cover of OY2-E-52427, we have the fallowing criticisms and notes to offer you :- The general arrangement of poles, terminals, and rotation, is exactly as in the Derby machine, but your big winding diagram appears to show that the machine will be operated with reversed polarity, in which case the positive of the battery will be earthed instead of the negative. As against this, the small diagram on your print A.9547 shews the negative of the battery earthed. In any case, this small diagram is surely wrong because it shews a series circuit of cutout series coil, cutout contacts, switch, and battery. We are therefore not sure what we are criticising. The control brush range is from 117° to 122° reckoned from what would be the positive brush in our case. The armature core end plates are described as insulation plates. This would appear to mean that the active length of the armature is less than that of the poles. The brushes shewn are of the wide type. It may be interesting to U.S.A. to know that we have recently standardised what we call N.B. machines, i.e. machines with narrower brushes (circumferentially), and probably better results would also be obtained on your 6-volt 29 coil 29 comm-utator segment machine with such brushes. We suggest that the D.O. here should forward particulars of this new brush gear. | ||