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).
Investigation into timing gear wear, oscillations, and material suitability for various engine components.
| Identifier | ExFiles\Box 107\2\ scan0162 | |
| Date | 11th April 1938 | |
| -2- of balancing cam plungers and we attach a print of these curves. These curves show that the camshaft balancer has a negligible effect at high speeds and may even be a disadvantage. We consider that the trouble we have had with sheared distributor driving pins indicates very violent oscillations in the timing gear drive. The inertia of a distributor is very small in comparison with the dynamo and the gears themselves, particularly as the dynamo runs at 3 times distributor speed. The gears have to oscillate these greater masses so it seems likely that the gears are subjected to very considerable loads. We do not believe that the loads causing the wear arise from the camshaft itself but rather either from crankshaft vibration or an oscillation in the timing train itself. The Coarse mesh Fabroil as now fitted to Wraith units is known to be liable to wear on Ph.III. A special fine mesh Fabroil was run on 32-EX and was 4 times as good as standard material. We believe that the Attwater's material which we are going to try on both Wraith and Ph.III will be better than either of the Fabroil materials, while being considerably cheaper. We are continuing the investigation on the gears of 26.G.VI in an attempt to obtain further evidence of the cause of the wear from the timing of the max. wear in relation to the timing of the crankshaft and camshaft torque. Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} | ||