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).
Meeting minutes discussing the cause of howling side shafts in gearboxes.
| Identifier | ExFiles\Box 75\1\ scan0007 | |
| Date | 22th December 1911 | |
| GEAR BOXES (Contd.) (8) X522 103rd Meeting Re Howling side shafts, Mr. Whitehead's note dated Dec. 22. 11. Mr. Nadin read a note from Mr. Whitehead (Tool Drawing Office) concerning the trouble we experienced with our side shafts from howling. The Committee agreed that this matter should be discussed at a special meeting that afternoon, when Mr. Whitehead should be asked into the meeting. Re Howling side shafts. Mr. Nadin read to the Committee Mr. Whitehead's note dated December 19th, 1911:- "Thinking it improbable that the intermediate are consistantly noisier in themselves than other gears we manufacture, I have endeavoured to find local conditions in the gear box which would accentuate their faults. The following theory explains all the facts known to me, and has the merit that it can easily be tested." "The sound is closely related to the engine speed for instance a certain side shaft was loudest on the notes (about) G to C (middle C on piano) when the engine speeds were 400 to 450 per minute. Note A (intermediate) is given by about 217 vibrations per second." We have 400 revs. x 30 (teeth or gears) / 60 seconds = 200 per sec. 450 x 30 / 60 = 225 per sec. "This result would of course be expected, but the noise given is a musical one, whereas the teeth would produce merely an uneven noise. Evidently therefore there is something in the box which vibrates freely at about 225 (say) times per second and harmonically." | ||