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).
The investigation and resolution of a 25 HP gearbox oscillation issue.
| Identifier | ExFiles\Box 137\4\ scan0345 | |
| Date | 11th May 1931 | |
| FOR FILES. 8634 25 HP. GEARBOX OSCILLATION. It was noticed on the production dynamometer that the front of the propeller shaft and rear of gearbox underwent a lateral oscillation of consideraule amplitude when running between 2500 and 3000 R.P.M. The frequency of the oscillation was found by the Rotoscope to be the same as the back axle RPM. The vibration was cured by fitting pneumatic tyres but could be reproduced by adding out of balance weights to these wheels. On the road with the rear wheels, 8 oz out of balance, no vibration built up at the critical speed, but the gearbox underwent considerable lateral movement relative to the frame side members due to road irregularities. This movement was entirely eliminated by fitting the Y. bracket support to the rear of the gearbox. 11.5.31. X.634. X.5310. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} | ||