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).
Recommendation to replace cast iron flywheels with steel ones on single-cylinder units due to stress concerns at high RPM.
| Identifier | ExFiles\Box 63\4\ scan0097 | |
| Date | 16th December 1929 | |
| To By.{R.W. Bailey - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Tsn. c. Wor.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} X4499 Hs{Lord Ernest Hives - Chair}/Tsn.1/MJ.16.12.29. FLYWHEEL FOR SINGLE-CYLINDER UNITS-E34561. X. 4499 X. 634 We observe that these have been instructed in cast iron; we have worked out the stress in these, under assumed extreme conditions of running at 4000 r.p.m. and find it could reach a figure of over 8 tons/sq.in. tensile. Although the original unit for compression ignition may not exceed a speed of approx. 2000 r.p.m. normally, similar units under F,H, or R cylinders will run up to 4000 r.p.m. normally, and, supposing a failure of water in the brake, to possibly well over this. We recommend that all the units be fitted with steel flywheels, including the compression ignition unit. Machinery's Handbook recommends 840 r.p.m. as a safe speed for 2ft. dia. cast iron flywheels. Hs{Lord Ernest Hives - Chair}/Tsn. | ||