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).
Revised 3rd and 4th gear synchromesh design for a B.V. type gearbox.
| Identifier | ExFiles\Box 99\4\ scan0234 | |
| Date | 24th November 1939 | |
| 428 SECRET. To Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} from Ev.{Ivan Evernden - coachwork} c. Rm.{William Robotham - Chief Engineer} c. Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} Ev.{Ivan Evernden - coachwork}10/MH.{M. Huckerby}24.11.39. B.V. GEARBOX. PL.55 REVISED 3rd. & 4th. SYNCHROMESH. This is FJH{Fred J. Hardy - Chief Dev. Engineer}'s synchromesh mocked up on a B.V. type gearbox. We find that it is not possible to use flat strip synchro springs as suggested by FJH.{Fred J. Hardy - Chief Dev. Engineer}, and we have used 6 spring loaded balls. The actuating ring slides on the sleeve containing the outer cones. Another construction should be possible with the actuating ring held clear of this sleeve, but this would be more complicated. We have not shown any anti-rattle, but this could be arranged as on Wraith. We show as an alternative a one-piece casting embodying both cones and the sleeve. This may be cheaper but it precludes broaching of the slots in the cones. What we have drawn in representative of a standard ratio gearbox with straight tooth 1st. and R.{Sir Henry Royce} gears, but may not be dimensionally correct for the particular gearbox on which you wish to try this scheme. We hope to use:- the 1st. motion shaft unchanged; the 3rd. driven gear with the cone dia. reduced; and existing cones GB.3959. Therefore, before we detail this scheme we require piece numbers of the following pieces from the box you intend to use:- 1st. Motion shaft 2nd. motion shaft cluster 3rd. speed driven gear 3rd. motion shaft 3rd. and 4th. operating fork. Guide and shaft for 3rd. and 4th. operating fork. Will you please decide on the actual gearbox you propose to treat and get the Expl. office to give us the detail numbers of the above pieces when we will proceed with the detailing of the scheme. Ev.{Ivan Evernden - coachwork} | ||