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).
Calculations for the B.60 engine damper inertia and stiffness.
| Identifier | ExFiles\Box 123\5\ scan0088 | |
| Date | 16th September 1938 | |
| To Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} COPY FOR FILES. 1044 Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}8/MH.{M. Huckerby}16.9.38. B.60 ENGINE DAMPER. Inertia. A = π/32 ( 7.8^4 - 5.25^4 ) x .878 x .283 = 72.3 About one half of B is effective due to holes for driving springs. B/2 = π/32 * 5.25^4 x .625 x .283 = 13 Total inertia 85.3 lbs.in^2 = .0185 slugs ft.^2 Equivalent crank inertia considered on nose of crank is about .02 for a stiffness of 50,000 lbs.ft/radius. NE To turn damper to 55% of 15,000 per minute Stiffness must be 50,000 x .55^2 x (185/200)^2 = 12500 lbs.ft/radius 220 lbs.ft/degree [Diagram with labels] .878 7.8 DIA A 5.25 Dia B .625 Gry{Shadwell Grylls} | ||