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).
Defining the standard test conditions and performance specifications for chassis dynamos.
| Identifier | WestWitteringFiles\L\2Jan1924-March1924\ Scan58 | |
| Date | 1st March 1924 | |
| To R.{Sir Henry Royce} from EFC. c. C.J. & FN. c. E.{Mr Elliott - Chief Engineer} & Da.{Bernard Day - Chassis Design} c. Ey. & EP.{G. Eric Platford - Chief Quality Engineer} X.294 - GENERAL CHASSIS DYNAMO OUTPUT PERFORMANCE and in particular X.4383 - DR. 20 HP. DYNAMO OUTPUT PERFORMANCE. Regarding the output performance of dynamos generally, we have for some time now had this defined on an unambiguous basis. There is first of all a general specification of electrical performance of each of the two dynamos, one for the 40/50 chassis and one for the 20 H.P. chassis. Up-to-date copies of each of these specifications are attached for your reference. On our bench test, dynamos of each diameter are clamped down in the same way, by means of metal clamps, to a cast iron bed plate bolted to the cast iron table. This gives unambiguity as to the rate at which heat flows from the dynamo at each temperature. Unambiguity in the ambient temperature is secured by stating that this shall not be less than 18°C, and in other respects the performance is defined as in the specification, the metal oil bath for the thermometer bulb forming a portion of the sheet copper strip clamped between the clamping bridge pieces of the carcase of the machine. There is a curve of specified performance given in the specification figures, and the dynamo, to comply with the specification, must have an output curve, under the conditions specified, lying everywhere above and to the left of the specified curve, when the dynamo is at a carcase | ||