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).
Involute tooth splines and a visit to G.M. Corporation to discuss cadmium and lead bronze engine bearings.
| Identifier | ExFiles\Box 173\4\ img121 | |
| Date | 23th November 1935 guessed | |
| -3- minutes difference between the angles of the inner and outer cones, and says they leave the tool marks in their outer cones to get a more effective bedding. They have experienced sticking and use 8° or 9° cone angle. Another argument for the involute tooth splines is that owing to the greater area and more accurate bearing on the spline faces, there is less likelihood of breaking down the oil film and so causing undue noise. Engine Bearings. We went to the Research Dept. of the G.M. Corporation yesterday and saw Mr. Rippingill and several of the research engineers and chemists. They confirmed what we had previously heard about cadmium bearings and added some further information. Cadmium bearings have three times the fatigue strength of white metal, and can run indefinitely provided a poor quality of oil is used. This is because the sulphur in the poor oil acts as a neutraliser to the acids which are formed. With a good quality of oil the bearings are completely worked out in a short while provided the temperature of the oil exceeds 225°F.{Mr Friese} This process is enormously accelerated by the use of lead fuel, so that the bearings may completely vanish in a few miles. But with the poor quality of oil containing sulphur neither heat nor lead fuel do any harm. They are of course abandoning the use of these bearings. Lead bronze bearings such as we are using require a very rigid shaft and a very rigid case, to run with white metal clearances. If there is deflection the clearance must equal the deflection. They have developed the tray method of making lead bronze strip bearings quenching the trays with a spray of kerosine oil, and are positive that these bearings will run satisfactorily in our engine with white metal clearances. The difficulty is to produce flanges, though one firm is so doing by stretching the metal of the tray into a flange, it was not clear whether with complete success. They will provide us with a set of trays for Bentley already quenched and with drawings or sketches of the apparatus for rolling the strip and finishing to size, if we are really interested. The thickness of the strip is such that either the crankcase would have to be reduced in bore, or the crankshaft increased in diameter. | ||