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 rattle noise occurring at 1500 r.p.m. traced to the fan pulley drive and crankshaft torsional oscillations.
| Identifier | ExFiles\Box 136\1\ scan0277 | |
| Date | 19th January 1938 | |
| -3- Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}4/JH.19.1.38. This occured at approximately 1500 r.p.m. and most noticeable when speeding up slowly and unaffected by tightly meshed gears or gears having .005 back lash, by 5 lbs. or 20 lbs. friction damping load, with or without the cam balancer, or thrust plunger on the end of the camshaft. One noticeable thing found was that all the noise was transmitted into the fan pulley for when removed the rattle could hardly be detected. As the fan pulley is virtually integral with the crank pinion we anticipate that if it were solid with the crankshaft this rattle would be less audible. Such a scheme has been issued (ECP.336) for trial in connection with the damping effect of the fan drive on the crankshaft torsional oscillations. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||