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).
Modification to the Spectre and Wraith gearboxes by reversing the hand of the gear spirals.
| Identifier | ExFiles\Box 94\1\ scan0034 | |
| Date | 21th September 1934 | |
| X4694 328 GRY{Shadwell Grylls} To ET. from HDY.{William Hardy} HDY.{William Hardy}4/EP.{G. Eric Platford - Chief Quality Engineer}21.9.34. c. Wor.{Arthur Wormald - General Works Manager} F.{Mr Friese} Hs.{Lord Ernest Hives - Chair} Ds. RMC. Hs{Lord Ernest Hives - Chair}/GRY.{Shadwell Grylls} SpectreCodename for Phantom III and Wraith Gearboxes. Will you kindly reverse the hand of the spirals of all of the gears for the forward speeds and reverse and of the spiral splines for the 1st speed wheels in these boxes. The object of this modification is to cause the unbalanced end thrust which results on the reverse shaft from the friction drag to tend to move the shaft into mesh on both the drive and the over-run. For the present the angles of the gears should be unaltered but we may make an alteration to the gears driving the reverse shaft with a view to balancing the thrust when allowance is made for the friction, but the difficulty here is to know what the minimum value of the friction will be. If we over estimate this value the shaft will work out on the drive. HDY.{William Hardy} | ||