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).
Friction torque measurements of steering bearings after a 10,000-mile test and subsequent alterations.
| Identifier | ExFiles\Box 95\1\ scan0257 | |
| Date | 1st January 1936 guessed | |
| -2- When the steerings of 32-EX and 21-G-IV were dismantled after 10,000 mile test it was noticed that the parallel rollers of the Adamant type cam bearings had been bedding on only one quarter of their length due to inaccurate grinding of either the inner or outer race tracks. This was likely to reduce considerably the friction caused by these bearings, so measurements were made of this friction. Friction Torque for one bearing in lbs/ins. per 1000 lbs. thrust. Incorrectly bedding parallel rollers 7.4 Correctly bedding parallel rollers 14.7 Timken bearing 16.5 The bearings of the steering of 21-G-IV were corrected for bedding and the gear refitted to the car. The first figures on the attached table refer to this condition. Unfortunately snatchometer figures could not be obtained before this alteration was made but by trial it was estimated to cause a 25% improvement. The results of the foregoing alterations, which reduce the mechanical efficiency of the gear, can be summarised by saying that they cause a small improvement but the joggles were still far worse than in the case of the La{L. A. Archer} Salle gear on Ph.III. | ||