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).
Experiments to determine the torsional deflection and rigidity of a Phantom crankshaft.
| Identifier | ExFiles\Box 25\3\ Scan147 | |
| Date | 9th September 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/ACL. c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to OY. X6324 Hs{Lord Ernest Hives - Chair}/ACLl/LG23.9.26. PHANTOM - CRANKSHAFT VIBRATIONS. X6324 X8010 X9840 In connection with the Phantom crankshaft vibration experiments we have taken a torsional deflection curve of this crankshaft supported in its bearings in the crankcase. For this purpose the flywheel was locked and a torque applied at the front end through an arm bolted to the spring drive hub. The torque arm was long - 4 ft. - to reduce to a minimum the downward thrust from the applied load. The actual deflection readings were made by a reflected beam of light on to a scale from two small mirrors attached to each end of the crankshaft. This method gives a high degree of accuracy and prevents errors due to any flexibility or slip of holding or twisting parts. A curve is appended giving the torque-deflection of the standard Phantom crankshaft between flywheel and spring drive hub when supported in its bearings. From the curve the torsional rigidity is 43500 lbs.ft. per radian of twist or 2.68 times stiffer than the 20 HP. We next determined the polar moments of inertia of all the crankshaft parts by the usual two wire suspension method. We obtained the following results. contd :- | ||