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 performance of Copper-lead and Babbitt bearings.
| Identifier | ExFiles\Box 115\5\ scan0216 | |
| Date | 6th December 1938 guessed | |
| 5. In comparison with the Babbitts, Copper-lead should give perhaps four or five times the life under quite moderate conditions. Where very high loads must be sustained especially at high temperatures where Babbit would crack in a short time, even better relative perfor- mance is obtained. All copper-lead compositions are well below babbitt with respect to anti-score quality, al- though definite differences are made by manufacturing conditions and composition. In common with most mater- ials which are not highlyresistant to scoring, it is not capable of conforming quickly to contortions of the shaft or of embedding dirt. With the lead as essentially a pure element, it is sub- ject to corrosion and when the lead dissolves in the lubricating oil, the remaining copper sponge compresses, thereby increasing bearing clearance, also with loss of the lead, the anti-friction quality is impaired. Lead Bronze bearings are therefore found in locations where a substantial increase over the life of babbitt is demanded but where only moderate anti-friction pro- perties are essential. 'Bus, Commercial Vehicle, Aero- plane and Diesel engines generally require the greater | ||