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).
Material change from cast iron to aluminium for a Lucas dynamo end cover and its effect on noise.
Identifier | ExFiles\Box 36\4\ scan 140 | |
Date | 13th October 1920 | |
R.R. 199 (250T) (SD676 19-7-17) MP182865 X 3014 B. Wd.{Mr Wood/Mr Whitehead} from BY.{R.W. Bailey - Chief Engineer} C. EPC. C. Des. C. Ms. STAMP: RECEIVED C OCT 13 1920 BY6-P12.10.20. RE LUCAS DYNAMO. X.3014 B. RE QUESTION OF SILENCE AS AFFECTED BY THE MATERIAL OF THE END COVER CARRYING THE OUTER BALL BEARING. Referring to the question of the change of the material from the original cast iron to aluminium on the above part, I do not consider that anybody at the Works should have instructed Messrs. Lucas to alter this without having submitted the matter to this department, as it represents a change in design which should not have been entered upon without careful testing. In view of the fact that Messrs. Lucas now confirm what we actually suggested would be the case at their visit, namely, that cast iron for the end cover would materially affect the question of noise, there can be no question but that since output of cars depends on dynamos, and that we cannot obtain a sufficient number of these quiet, with aluminium end covers, the Lucas Company should at once revert to the use of cast iron. So far as experimenting is concerned, we have no objection to them carrying out further experiments with modified designs of aluminium cover, as suggested to them at their visit, but these should not be adopted until we have satisfied ourselves that silence can be maintained whilst using aluminium. The whole issue resolves into the fact that it is more important to obtain quiet dynamos than light dynamos, although the ideal we aim at is lightness and quietness combined, but if we have to make a choice or compromise it certainly must | ||