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 of a broken Bentley rear axle driving dog with two suggestions for strengthening the component.
| Identifier | ExFiles\Box 84\4\ scan0039 | |
| Date | 4th October 1934 | |
| x202 GRY{Shadwell Grylls} See me To BY.{R.W. Bailey - Chief Engineer} from Da.{Bernard Day - Chassis Design} c. Nor. E.{Mr Elliott - Chief Engineer} Hs.{Lord Ernest Hives - Chair} Wdy. RHG. Bentley Rear Axle Driving Dogs. The driving dog which broke did so not at the weakest point of the boss, but at the place where the flexible boss changes into the very stiff web. The boss at this point is approximately 20% weaker than the driving shaft. When the boss has been broken off the area of serration left is too small to carry the load for long. On N. Sch.4215 herewith are shewn two suggestions for strengthening. In both the length of serration under the stiff web has been increased. In the upper suggestion the boss is strengthened all the way along to approximately 40% stronger than the shaft, the running clearance with the tube being .025 to .035 in diameter. In the lower suggestion the boss is tapered continuously from a diameter slightly less than the present smallest diameter to a diameter approximately 30% greater in strength than the present largest diameter, so taking up the load gradually. We prefer this one if the manufacturing difficulty is not too great. Da.{Bernard Day - Chassis Design} | ||