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).
Design alternatives for the S.M. Gearbox clamping mechanism and Woodruff key.
| Identifier | ExFiles\Box 15\5\ Scan309 | |
| Date | 30th May 1932 | |
| E.{Mr Elliott - Chief Engineer} FROM DA.{Bernard Day - Chassis Design} C. TO HS.{Lord Ernest Hives - Chair} P. 2. S.M. GEARBOX. X7310 DA{Bernard Day - Chassis Design}1/M30.5.32. X.7310 With reference to HS{Lord Ernest Hives - Chair}/GRY{Shadwell Grylls}6/KT25532., and LeC.3106., we should like to point out that the Woodruff key will be slightly slack, and the mechanism depends for its tightness on the clamping. This was the reason for using a taper pin in the originaldesign. It was intended that the rocker shaft and stirrup should be erected as a unit outside the box, and never taken apart. The design was made so that this could be done. It would be possible to have a .250 taper pin without unduly weakening the shaft, which almost doubles the shear area of the pin. Alternatively it would be possible to have the .312 clamping bolt, which we believe would raise the friction above any ordinary handling load. DA.{Bernard Day - Chassis Design} | ||