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).
Slackness of a Woodruff key and proposing alternative pin or bolt solutions for an S.M. Gearbox.
| Identifier | ExFiles\Box 178\3\ img187 | |
| Date | 30th May 1932 | |
| L. FROM DA.{Bernard Day - Chassis Design} C. to HS.{Lord Ernest Hives - Chair} P. 2. S. M.{Mr Moon / Mr Moore} GEARBOX. DA{Bernard Day - Chassis Design}1/N30.5.32. x7310. 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 original design. 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} | ||