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).
Technical memorandum discussing dynamo overheating during testing and proposals for improved cooling and ventilation.
| Identifier | WestWitteringFiles\I\July1922\ Scan100 | |
| Date | 18th July 1922 | |
| Contd. -2- will exceed that on the bench though it is considered likely that it will. It is now arranged, however, that a test be made, as soon as a dynamo is available, of measuring the temperature of the carcase on the chassis in the same way that we measure it on the bench - it may then be inferred that the internal temperature of the dynamo bears the same relation to the carcase temperature as on the bench. We do not on the bench run the solder off when running the carcase continually at 90°C (N.B. The temperature of melting solder is 180°C). On the bursting tests of commutators the carcase temperature was 130°C when the solder on the commutators was just melted and a similar relation might approximately hold in the dynamo case. If so, it would appear to show that the dynamo on the car reaches a much higher temperature than on the bench for an equivalent setting of the brushes. The heating of the dynamo can, of course, be reduced and matters improved in this respect by altering the brushes so as to reduce the output, but then we cannot afford to reduce the output to an appreciable extent. It would be much better, if possible, to arrange some sort of ventilation for the dynamo, as this would have a doubly good effect and also enable the dynamo to give more output. We have at any rate now come to the conclusion that unless something is done to cool the dynamo more efficiently than at present, some trouble may be expected. WWN | ||