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).
Experimental modification to the Phantom III gearbox using acme splines.
| Identifier | ExFiles\Box 94\2\ scan0007 | |
| Date | 10th June 1938 | |
| X320 GRY{Shadwell Grylls} Please follow up this EXPT. Rm{William Robotham - Chief Engineer} DY.{F R Danby} C. Ey.Rd. Hs.{Lord Ernest Hives - Chair} LHC. HS{Lord Ernest Hives - Chair}/FM. E/HDY.{William Hardy}1/RP.10.6.38. Gearbox - Phantom III. We send herewith N.Sch.4820 which shews acme splines for the 2nd speed sliding piece. These should be tried with the object of preventing the 2nd speed from working out of mesh. With the acme spline there will be a greater load on the spline surface than corresponds to the radial distance of the surface from the shaft/centre. For experimental purposes an existing shaft can be ground down and a sleeve substituted for the 1st speed pinion. The splines of the 2nd speed sliding piece need not be hardened for experimental purposes. It will not be possible to tell whether this scheme is immune from the trouble of working out of mesh from a single example of course, but some idea may be gathered by determining the loads required to pull the gear out of mesh under various running conditions, and comparing these with corresponding loads on the standard car. A print is attached to Rm{William Robotham - Chief Engineer}'s copy. E/HDY.{William Hardy} N.Sch.4820. | ||