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).
The testing and noise comparison of unground first-speed gears for Bentley models.
| Identifier | ExFiles\Box 136\5\ scan0324 | |
| Date | 14th December 1937 | |
| By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} Da.{Bernard Day - Chassis Design} Hdy.{William Hardy} RHC.{R. H. Coverley - Production Engineer} 1132 Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}2/AP.14.12.37. 1st. SPEED GEARS. A short time ago RHC.{R. H. Coverley - Production Engineer} made for us two pairs of Bentley first speed unground gears. The first of these was fitted to 50.BN.{W.O. Bentley / Mr Barrington} Although the type of noise was different from the usual ground gears the total amount of noise was little if any different except for slightly more growl at very low speeds. The second set was lapped and after lapping showed that most of the polishing had taken place on the pitch line. This pair was fitted to C.B.IV. and was considerably noisier than the first pair. It should be remembered that the standard Bentley 1st. speed is very noisy compared with P.III. or Wraith. We are accepting a spur 1st.speed on Bentley 50. It is a gear very seldom used. If it simplifies the box to arrange it so that the 1st. speed gears cannot be ground we recommend doing so. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} | ||