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).
Comparison of the properties and advantages of R.R. bearing alloy against other materials like babbitt and lead bronze.
| Identifier | ExFiles\Box 115\5\ scan0184 | |
| Date | 21th November 1938 | |
| R.R. BEARING ALLOY. The big advantage of this material over babbit is that it does not suffer from fatigue, which is the main disability of the latter material. It is impossible to give precise figures as to the actual load capacity of the material, owing to the fact that shaft or crankcase distortion can naturally affect its behaviour seriously. Given reasonable conditions, however, it can certainly carry 50% higher load than babbit. Comparing it with lead bronze, in our experience its advantages lie in the fact that it is far easier to produce, its behaviour is more consistent, and its tendency to seize during shaft distortion is less marked. In the case of the R.R. alloy and lead bronze, it is necessary to have better filtration to prevent scoring than with an ordinary white metal bearing. It is also true that a babbit bearing will function with a moderate supply of oil, whereas both lead bronze and R.R. alloy will resent any shortage. There is no difficulty, however, about getting an adequate supply of oil to the bearing if the pump and the passages are adequate. An advantage which the Rolls-Royce aluminium tin alloy possesses over most lead bronze is that it does not suffer from corrosion due to acidity in the oil. Lead bronze has now been almost entirely abandoned in the United States owing to its susceptibility to acid attack. Rm.{William Robotham - Chief Engineer} | ||