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).
Steering experiments and modifications for the 25 HP and Phantom III models.
| Identifier | ExFiles\Box 95\1\ scan0256 | |
| Date | 1st January 1936 | |
| PROOF. 1.1.36. Steering Experiments on 25 HP. and Ph.III. This report is a continuation of our Hs{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer}2/KW.26.6.35. At the time of this previous report it was thought that the superiority of the La{L. A. Archer} Salle gear on Ph.III was due to its irreversibility. Static efficiency measurements had been carried out which showed that the only difference between the R.R. and La{L. A. Archer} Salle gears was that the former remained efficient at high loads while the latter fell from 78% at 100 lbs. on the pendulum lever end to 60% at 1,000 lbs. The following modifications were therefore tried in order to reduce the efficiency of the R.R. gear by providing friction proportional to load :- (1) Crowning of cam track reduced from 0.005 to 0.002". (2) Timken bearings on the cam and roller in place of the Adamant type parallel rollers. (3) Helix angle reduced from 6° 35' to 5° 48'. Item No. 1 above was tried on the last 10,000 miles Ph.III, 31-EX, and made no improvement to the joggles. The remaining alterations were tried first on 21-G-IV and later on various Ph.III chassis. The results obtained are shown on the attached table. | ||