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).
The abrasiveness and instability of certain EP lubricants containing clay.
| Identifier | ExFiles\Box 114\1\ scan0086 | |
| Date | 11th January 1937 guessed | |
| axle which is run 25,000 miles, that we can safely say this is a true indication of the abrasiveness of the lubricants. Also evidence is obtained by examining the lubricant itself at the conclusion of these tests such as measuring its load carrying capacity and abrasiveness on the Timken testing machine and by analyzing the oil for iron content and other substances which may indicate wear. It is a definite fact that some "EP{G. Eric Platford - Chief Quality Engineer}" lubricants are made from mineral oils which contain abrasives at the very outset. We have frequently found at the conclusion of a test, a white solid pasty substance centrifuged out on the inner surfaces of the bearing cages and after careful chemical analysis, found that it was foreign to any of the materials used in compounding the oil, nothing but clay. Some mineral oils used in the compounding of "EP{G. Eric Platford - Chief Quality Engineer}" oils have been found by chemical analysis to contain clay which is a highly abrasive substance. Oils which are unstable in long time tests show a considerable diminution of load carrying capacity and a great increase in abrasiveness as indicated by the iron content in the lubricant. - 11 - | ||