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).
Mr. Royce's remarks on the manufacture of dynamos and starter motors.
| Identifier | ExFiles\Box 68\4\ scan0220 | |
| Date | 2nd August 1921 | |
| To Da.{Bernard Day - Chassis Design} from EFC. c. By c. Da{Bernard Day - Chassis Design}/Thr. c. By/WER. X. 1640 EFC2/T2.8.21. X.294- DYNAMOS & MOTORS MANUFACTURED BY R.R. X.1640 X.543. During my visit to Mr. Royce he made a number of general remarks in connection with the R.R. manufacture of dynamos and starter motors. He stated that flaked mica and not sheet mica should be used for separating the plates of the armature. It may be remembered that in his R6/C22.3.20 with reference to the R.R. dynamo made from starter motor parts, he stated that the armature core should be of plain discs built up with shellac and flaked mica, heated, pressed and screwed up while at the temperature of melting shellac, and turned and ground on the outside. He stated that owing to the ample size of the R.R. dynamos and motors they will be able to have punched teeth. He decided that the commutator end bearing should be carried on two arms only in a manner similar to that of the Rotax AT.12 dynamo, giving a clear view of the commutator and simplicity of casing. Terminals to be on the carcase and to be covered. He considered that 1/3 of the armature diameter should be allowed at each end for end connections, not including the commutator spokes at the commutator end, for both motors and dynamos. He queried as to whether we should require more room than this at the commutator end. Thus for a 3" armature with 1" end connections at the back end would be required, and 1 1/4" at the commutator end, including | ||