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).
Engine shaft calculations, Peregrine critical speed, and proposed improvements.
| Identifier | ExFiles\Box 85\5\ scan0004 | |
| Date | 15th April 1932 | |
| Sheet 2. E.7/HP.15.4.32. The web width is already as large as it should be judging from our model experiments of some time ago. The Peregrine major critical was calculated at 5750 r.p.m. by deduction from J.III and 5000 with a supercharger hung rigidly on the end like the Alfa. We propose to drive the blower with a very flexible shaft so as not to split the critical speed, and no doubt we shall require a damper on front end of crank. The shaft is being calculated to the afore mentioned proposed dimensions and if it is deemed that insufficient improvement has been made then it may be necessary to increase the crankpin size and accept the attendant disadvantages of withdrawing from below, larger banjo and timing gears etc. E.{Mr Elliott - Chief Engineer} | ||