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).
Outlining improvements for the Spectre Gearbox regarding heavy operation when cold.
| Identifier | ExFiles\Box 94\1\ scan0079 | |
| Date | 3rd January 1935 | |
| SECRET. <328 To. Ev.{Ivan Evernden - coachwork} from HDY.{William Hardy} HDY.{William Hardy}1/HP.3.1.35. c. Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} RHC.{R. H. Coverley - Production Engineer} Ey. Ds. [Signature] GRY{Shadwell Grylls} SpectreCodename for Phantom III Gearbox. Heavy Operation when Cold. We are issuing today designs for needle roller bearings for the gears constantly in mesh and for gears giving a 10% higher first speed (suggested by Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} in view of the lower axle ratio). The improvements that will have been instructed are therefore as follows:- 1st Speed. (1) M.{Mr Moon / Mr Moore} Sch.4275 Increased leverage of actuation gives 36% improvement. (2) N. Sch.4326 Higher 1st speed gears give 10% improvement (3) N. Sch.4321 needle roller bearings. 2nd Speed. N. Sch.4321 needle roller bearings for the 3rd speed wheel and spigot bearing will help but these for the 2nd speed pinion are detrimental. A reduction of cam angle would help but so far we have not been able to use less than 50°, the present angle. An increase of 2nd speed gear ratio would help but as 1st speed has no synchromesh it is desirable that 2nd speed should be kept low. 3rd Speed. Needle rollers for the spigot will help but the others are detrimental. CONTINUED. | ||