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).
Tests carried out on road springs to determine internal friction under various conditions.
| Identifier | WestWitteringFiles\S\September1928-October1928\ Scan042 | |
| Date | 1st September 1928 | |
| To R.{Sir Henry Royce} from HS{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c.c. to BJ. Wor.{Arthur Wormald - General Works Manager} c.c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c.c. to BY.{R.W. Bailey - Chief Engineer} X 8410 HS{Lord Ernest Hives - Chair}/Rml/LGS. 9. 28. ROAD SPRINGS. With reference to R2/M20.7.28 and R1/M23.7.28, we have carried out tests to determine :- (1) Whether the internal friction of the present standard 40/50 rear spring when new and normally greased and clean is appreciable. Graph A shews that it is not very great, half the difference between the loading and unloading curves being only about 25 lbs. For this test the spring was supported at the centre on a knife edge and loaded at the tip. The central bolt held the leaves together. (2) Whether the internal spring friction can be appreciably reduced in a new spring by cadmium plating. Graph B. shews test 1. repeated on the same spring after cadmium plating. Half the difference between loading and unloading in this case is about 15 lbs., a reduction of 40%. This is probably largely due to the fact that the plates are cleaned up before they are cadmium deposited. (3) Whether the spring clips and pad make an appreciable difference to the spring friction. Graph C. shews the result of repeating test 2; with the pad and clips fitted. The difference does not appear to be detectable. (4) Whether the internal spring friction increases appreciably after the spring has been in service a short time without lubrication being forced between the leaves. Graph D.{John DeLooze - Company Secretary} shews the very marked increase in internal friction that takes contd :- | ||