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).
The use of solid versus laminated poles and armatures for various dynamo and motor models.
| Identifier | ExFiles\Box 64\1\ scan0264 | |
| Date | 8th December 1926 | |
| [Handwritten]: X7620 EFC5/T8.12.26. [Handwritten, top right]: 4 DYNAMO & MOTOR POLES AND ARMATURES Phantom Dynamo. [Handwritten]: X8660 ✓ Pole pieces are solid. An experiment is in hand with punched armature plates with no insulation other than oxide or varnish. Phantom 6" Starter Motor. [Handwritten]: X8620 ✓ Field poles are laminated but being obtained from outside, and it is suggested that no saving would be effected by making these solid. A brake efficiency test was made sometime ago on a motor experimentally fitted with solid poles, results of which were equally as good as those from a standard motor. Phantom Sequence Starter 5" Motor. [Handwritten]: X7620 ✓ Pole cores of this machine are solid. 20 HP. Dynamo. [Handwritten]: X4638 X5660 Field poles of this machine are laminated, but a test has been made on solid poles on the strength of which a standardisation sheet for solid poles is being circulated, as it is said that a saving of 6/4d. would result. [Handwritten]: Stadd 20 HP. Starter Motor. [Handwritten]: X4132 X5620 This has laminated pole pieces, and it has been suggested by Mr. Clough in his BY/Cgh{W Clough}21/G3.12.26, that we should also use solid pole pieces on this motor, and that he proposes to instruct same experimentally with a view to standardisation. [Handwritten over text in red]: Stadd In view of our results on the 6" 40/50 motor, we do not consider it necessary to make brake efficiency tests, but regard the matter wholly as one of manufacturing costs. The change should therefore be decided on that basis. EFC. [Handwritten]: Stadd | ||