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).
Improvements made to the Goshawk dynamos, detailing changes to brushes, springs and the commutator.
| Identifier | WestWitteringFiles\K\November1923\ Scan46 | |
| Date | 14th November 1923 | |
| R.R. 493A (40 H) (SL 42 12-7-23). J.H.,D.{John DeLooze - Company Secretary} EXPERIMENTAL REPORT. Expl. No. 14353. REF:EPC/M14.11.23. X4353 To R.{Sir Henry Royce} from EPC. C. CJ. C. EY. C. Mr. Brock. RE GOSHAWK DYNAMOS. With reference to your RS{Sir Henry Royce's Secretary}/M12.11.23, it is considered that with the various minor improvements, the machines which are now being turned out can be expected to give reasonable satisfaction for a long period of use, the various improvements being as follows:- (1) Improved position of main brushes. (As Compared with original position). (2) More uniform dimensions of brushes and brush holders. (3) More uniformity in brush springs, and freedom from these catching on the stud heads in brush holders. (It is a very difficult matter to get the spring makers to keep to the uniformity on the production of these springs, which we desire, the type of spring not lending itself easily to such uniformity). (4) Reduction of ampere output on peak by 1 ampere. (5) More careful bedding of the brushes. (6) Bevelling the tops of the brushes. (7) Improved method of undercutting the commutator. As regards the brush material, we have tried brushes of material similar to that used by Bosch, viz. L.F.C.3b Le Carbone and H.M.6 Morganite. As reported, the L.F.C.3b did fairly well, but not as good we think as the present standard. The actual brush used on Bosch is L.F.C.2. Both brushes are soft graphitic, but according to the makers' lists they are not of higher resistance than our present standard brushes, the values being as follows :- Contd. | ||