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).
Fix for rattling Servo Reduction Gears by adjusting keyway slack.
| Identifier | ExFiles\Box 73\1\ scan0208 | |
| Date | 26th September 1924 | |
| U.W. X9910 Srt. [Crossed Out] Mr H...th. [Crossed Out] Hs.{Lord Ernest Hives - Chair} [Crossed Out] Er. [Crossed Out] Her. [Crossed Out] EY2/H.{Arthur M. Hanbury - Head Complaints} 26.9.24. ------------- SERVO GEARS. ------------- Hs{Lord Ernest Hives - Chair} has discovered a means for eliminating the rattling on the Servo Reduction Gears which has prevented us delivering cars as being satisfactory up to the moment. The scheme for overcoming the trouble is that the large driving gears, the last gear in the train which drives the servo itself, is fitted slack on the keyways and not locked up when the end nut is screwed up tight. The amount of play on the keys which is required to cure the trouble is .005" to .010", and there should be at least .005" axial movement on the wheel to ensure the latter not being tightened up solid as the frictional grip of the nut is quite sufficient to bring the trouble on, even when the keys are slack. Will the Works therefore kindly arrange to treat this particular gear on all cars in the manner indicated above, before delivering cars. After discovering the cure, Hs{Lord Ernest Hives - Chair}, Mx{John H Maddocks - Chief Proving Officer} and myself went out on a chassis from the Test Dept. which was apparently precisely similar to the ones that Hs{Lord Ernest Hives - Chair} had worked upon. It was agreed after running the car that it was precisely similar, and it was thought that it would prove to be slack on the keys and in fit endways. An examination of the car proved this to be the case so that up to the moment we had never produced any gears free of the trouble. The freedom from trouble which has occurred in two or three exceptional cases being due to the wheel being slack on the keys. BY.{R.W. Bailey - Chief Engineer} RY | ||