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).
Further tests into road spring friction, detailing the issue of 'digging-in' on serviced springs compared to new ones.
| Identifier | ExFiles\Box 52\2\ Scan176 | |
| Date | 29th September 1928 | |
| To R. {Sir Henry Royce} from Hs {Lord Ernest Hives - Chair} /Rm. {William Robotham - Chief Engineer} c. to BJ. Wor. {Arthur Wormald - General Works Manager} c. to E. {Mr Elliott - Chief Engineer} DA. {Bernard Day - Chassis Design} c. to EY. OY. X4429 Hs {Lord Ernest Hives - Chair} /Rm {William Robotham - Chief Engineer} 2/LG29.9.28. ROAD SPRINGS. X840 X30524 In continuance of our report Hs {Lord Ernest Hives - Chair} /Rml/LG8.9.28, we have been carrying out further tests on spring friction. Our impression in suspension tests has been that if we take a rear spring that has been in service some little time and grease it, we do not get such good results as if we fitted a new spring. The reason for this appears to be the digging-in that takes place at the end of the leaves after running. This in some cases is most pronounced. We took the spring whose internal friction is shewn in Graph D. {John DeLooze - Company Secretary} and repeated the test shewn in Grapg E. {Mr Elliott - Chief Engineer} We then dismantled the spring, carefully cleaned and greased it, and took another curve of the internal friction - Graph F. {Mr Friese} By comparing graph F. {Mr Friese} with graph A. {Mr Adams} in our [struck-through]previous[/struck-through] previous report, it will be seen that a new spring has only about half the internal friction of a spring that has seen service though both are freshly greased and cleaned. The Repair Dept. have carried out some tests and are satisfied that, by polishing up springs that have been in service and cleaning up the places where digging-in has occurred, they can get an appreciable improvement in riding which they cannot get by simply cleaning and greasing the springs. Summarising the rear spring position - Cadmium plating is an advantage from the internal friction point of view but it cannot overcome digging-in which appears to be the worst evil. contd :- | ||