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).
Technical memo discussing the properties and performance of white metal for engine bearings, focusing on tin content, adhesion, and yield point.
| Identifier | ExFiles\Box 114\2\ scan0240 | |
| Date | 28th November 1935 guessed | |
| - sheet 2 - Bearing Metal. Brinell Cold. Brinell at 150°C. Yield Point at 150°C. White metal. 26 6.7 .55 tons. The liner material contains 17% of tin to make it suitable for adhesion in a shell, and the more the tin the greater the adhesion, and the lower the yield point at 150°C. It is somewhat significant that Hs{Lord Ernest Hives - Chair}/Royce ran two lined bearings in a single cylinder engine of 17% and 23% tin content and got a better result with the latter. This 23% tin alloy has a yield point of only 2 tons. The Kestrel engine has been built up with 20% tin lined bearings of about 2.7 tons yield point to allow for soft shaft and for easier manufacture. This same material is also used on the bearing separators of the Bentley because of its better adhesion. Weighing, therefore, all the evidence at the moment it does look as if for a liner material we may have to accept a lower yield point by increasing the quantity of tin which at the same time should give easier manufacture and better adhesion to prevent the metal coming adrift at bearing working temperatures. At the same time I think some further light might be thrown on this problem by testing main bearings in the solid material, which bearings I understand are ready and available. E.{Mr Elliott - Chief Engineer} | ||