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 the Dennis crank, identifying high bearing pressures and proposing design improvements like adding more bearings or balance weights.
| Identifier | ExFiles\Box 116\1\ scan0062 | |
| Date | 7th September 1938 | |
| Rm.{William Robotham - Chief Engineer} ------- BY.9/G.7.9.38. /1020a I am in agreement with Mr. Bower's conclusions in regard to the Dennis crank, as given in his report BY/B.2/G.7.9.38. Broadly speaking, the crankshaft lacks scantling, with the result that the bearing pressures per square inch are too high for regular running. The deflection of the central journal under load is a contributory factor to failure, particularly if the centre housing and web is ribbed up to give a high stiffness factor. [handwritten in red: omit] The design demands either more bearings adding to reduce the load and deflection on the existing bearings or alternatively balance weights should be added to reduce the inertia loading, but this would still leave the distortion effect on the centre bearing as the result of gas pressure on 2 and 3 pins. BY.{R.W. Bailey - Chief Engineer} By | ||