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).
Test report on a 25 HP low inertia spring drive, detailing damping load experiments and modifications.
| Identifier | ExFiles\Box 137\4\ scan0391 | |
| Date | 30th September 1931 | |
| X634. 30.9.31. 25 HP. LOW INERTIA SPRING DRIVE X5020. This type of slipper wheel has been fitted to units C.1, C.9 (transferred to R's car C.3 unit), 14-G6 and C.7 (10,000 miles). The original damping load on C.7 was 12 lbs. at 1 7/8 radius. Like this there were no crankshaft torsional vibrations. GWH.{George W. Hancock - Head Chateauroux} reduced the load to 8 lbs to overcome thumping but this brought up the half period. Experiments on C.1 unit showed that damping friction of 13 lbs was difficult but that 10 lbs. was not. On 14-G6 recent tests starting with 3 lbs at which load the 1/3, 1/2 and 2/3 periods were violent, we found 10 lbs insufficient but that with 17 lbs all vibrations were absent and that neither thumping nor bushknocks were apparent. Double driving springs were fitted and damping springs of to E.56208 of free length .700. Three cotton ducks were used two in front of the metal disc. Experiments will be done on C.1 with springs of free length .850 to get the required damping load. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} | ||