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 principles and stiffness of crankshafts.
| Identifier | ExFiles\Box 6\1\ 01-page086 | |
| Date | 23th November 1927 | |
| HS.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} RG.{Mr Rowledge} BY.{R.W. Bailey - Chief Engineer} c. to BJ. Wor.{Arthur Wormald - General Works Manager} +5010 RI/M23.11.27. CRANKSHAFT - STIFFNESS. X.8010 X.3865 X.8010 All our shafts must be looked upon as continuous, (not just single cranks.) Bearings must only be asked to keep the centre of their length in place, but not the journals in line, because if the housings were rigid enough, (they cannot be) the bearings would only become bell-mouthed. So that things have proved that journals, webs, and pins, must all be as rigid as possible. As the journals are the easiest to make of increased dia., we do so until we are up against some limit. When we come to the webs we can only increase these in width because we must have all the bearing area. This has been done increasingly during the last few years and is now up to the limit of advantage for weight. We have now tried to economise (out of balance and inertia reduction of weight) by reducing the pins, but have definitely had a set-back that these must not be altered in this direction, so we must go larger whenever opportunity allows. We are not altering Phantom or 20 HP. from our present standard: if we were to we should increase, because decrease has shewn up to be definitely bad. The 'H' engine crank pins should be increased slightly. R.{Sir Henry Royce} | ||