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).
Research on cast iron crankshafts, comparing fatigue strength and design.
| Identifier | ExFiles\Box 132\1\ scan0036 | |
| Date | 2nd March 1938 | |
| By.{R.W. Bailey - Chief Engineer} from Rm.{William Robotham - Chief Engineer} 1116 Rm{William Robotham - Chief Engineer}6/R.2.3.38. We note that the A.I.E. Research people have been doing a lot of work on cast iron crankshaft, and have come to the conclusion that these shafts when made in the type of iron as used by Leylands are likely to have 30% reduction in fatigue strength. We have also come to the conclusion that this lack of fatigue strength could be largely eliminated by attention to design. It would still appear to us to be of value if we could get an analysis of the stress to which our P.III crankshaft is subjected compared with that of the Bentley and that of the aero engines. The main point is that our crankshafts are designed for torsional rigidity, and are, therefore, far stronger in this connection than they need be. Also we have a 7-bearing which gives us a tremendous advantage on bending over people like Fords who are already using cast iron crankshafts. Rm.{William Robotham - Chief Engineer} | ||