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).
Dynamo performance, comparing machines and detailing a new test rig setup.
| Identifier | WestWitteringFiles\J\December1922\ Scan71 | |
| Date | 7th December 1922 | |
| Contd. -2- EFCB/T7.12.22. armature. a thou. or two of eccentricity or error on the air gap making quite an appreciable difference). Curves of the falling away of the field current with increasing speed for the hot condition are also shown. Also for comparison an output curve of the 40/50 Lucas E.575 machine (average of a number of machines) in the hot condition is shown, so that the lateness of cutting in of this machine, even in comparison with the Goshawk machine, can be judged. The old dynamo bench rig on which the dynamo is clamped between wooden blocks has now been superseded by a metal rig on which the dynamo is clamped between cast iron blocks and a considerable amount of cooling by conduction through these to the cast iron table will take place, so that any further curves of performance will be on a different basis, and it will be necessary to revise the specification of performance under these conditions. The probability now is that the dynamo on the bench cannot attain a temperature that it can attain on the engine. Previously, however, it might be considered that the dynamo could get as hot on the bench as on the engine, particularly taking into account the fact that the temperature of the dynamo on the engine cannot exceed that of the engine itself, by more than a certain amount, depending on the conductivity of the mounting. Curves of performance of an up-to-date dynamo on the new rig are being prepared. EFC. | ||