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).
Analysis and proposed tests regarding 1st speed gearbox noise, comparing Morris and Austin designs.
| Identifier | ExFiles\Box 136\2\ scan0335 | |
| Date | 30th June 1941 | |
| -2- or type of prop. shaft. It would be useful to try a Morris 10 for 1st. speed noise, as the Morris 10 has the same gearbox as the 8, but without the extended 3rd. motion shaft, and may be mounted differently from the 8. An alternative argument is that we are wrong in considering B.V. at all, since B.V. tooth form, correction, and contact ratio may be intrinsically good and the gear is noisy only because it is not near a wall of the gearbox. We think this argument is weak, but if we accepted it we could say that we know how to copy the Morris 8 design of 1st. speed without achieving the Austin 8 noise. Even so, to apply the Morris 8 1st. speed to our Junior box is not easy. We cannot have 1st. speed at the back of the box and retain Timken layshaft bearings; and plain layshaft bearings, especially on the Austin 8, do not look good. Furthermore, the Morris 8 1st. speed tooth ratio has been improved at the expense of the constant mesh ratio, and if we had the Morris 8 constant mesh gears we could not grind them. These are the tests we would like to make. Try a Morris 10 for 1st. speed noise. Try a Morris 8 with its gearbox mounted like the Austin 8, if possible. Find another quiet gearbox with straight 1st. speed. Have the tooth profiles of the various 1st. speed gears accurately compared. We have drawn the Austin 8 and Morris 8 gearboxes from actual pieces. The drawings are PL.711 and PL.712 respectively, and are attached to Rm{William Robotham - Chief Engineer}/HH's copy for issue and filing. Ev{Ivan Evernden - coachwork}/Tln. Tln. Original of PL.711 and PL.712 - Rm{William Robotham - Chief Engineer}/HH. Prints Rm{William Robotham - Chief Engineer}/HH. Ev.{Ivan Evernden - coachwork} Ev{Ivan Evernden - coachwork}/Tln. & Ashby. | ||