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).
Experimental test results of machines with varying cast iron and M.S. pole pieces and cross-sectional areas.
| Identifier | WestWitteringFiles\L\2Jan1924-March1924\ Scan71 | |
| Date | 13th March 1924 | |
| Contd. -3- EFC1/T13. 3. 24. In the first instance, the machines for experimental test were built with cast iron pole pieces, in accordance with LeC. instructions, the section of the pole core being 3.45 sq.ins. General specification output curves ( i.e. as described in our EFC2/T3. 3. 24) obtained for two experimental test machines C and D with cast iron pole pieces of this section are shown on one of the accompanying sheets of curves. The late cutting in performance with these poles will be noticed, though the ampere output peak is reasonably O.K. On one of the experimental test machines, known as B, the cast iron pole pieces were changed for M.S. pole pieces, originally of the same dimensions, and it was then found that the cutting in of the machine was greatly improved, but that the machine suffered from over-control. A step by step process of cutting down the field poles to give core cross sectional areas of 2.86, 2.535 and 2.23 sq.ins. in succession was adopted, and the general specification performance of the machine investigated at each stage. From this it was decided that the third variation, namely 2.535 sq.ins., gave the best general result for these M.S. pole pieces, and the actual curve obtained is shown (triangular points), together with those above referred to, on the same sheet of curves. There is shown (triangular points) for comparison also on the same sheet; the present standard Lucas dynamo output Contd. | ||