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).
Temperature testing of commutators made from various moulded materials.
| Identifier | WestWitteringFiles\I\July1922\ Scan69 | |
| Date | 1st July 1922 | |
| Contd. -2- EFCL/TS.7.22. within a few degrees of the average temperature of the carcase metal. The temperature of the commutator under test will probably be some 10 or 20 degrees higher than this recorded figure. Since it is likely that the difference between the temperature taken in this way on the dynamo and the actual temperature of the commutator running on the dynamo is greater than the difference above mentioned, we allowed for this by running up to a considerably higher observed temperature than in the case of the dynamo normally running. Up to the pres- ent the commutators tested have consisted of those moulded with various materials comprising - (1) Asbestos filled Elo, obtained from Fleming, Birkby & Goodall) (Black). (2) Plain Elo (red) (3) Mouldensite obtained from J.A. Hill, Ordnance Works, Sheffield. which is now being manufactured in a Works they have instituted at Darley Dale, Nr. Matlock. (4) Ordinary Bakelite (as obtained from U.S.A.) in each case built up with segments of shape inaccordance with sample attached to R's copy, and labelled (3). A schedule of the various tests concluded to date is given herewith, in which only the tests with heating are included, as no bursting has, as previously remarked, taken place cold. Contd. | ||