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).
Quenching problems with marine type bearings, alternative materials, and a visit to Cleveland Graphite.
| Identifier | ExFiles\Box 173\2\ img136 | |
| Date | 14th February 1934 guessed | |
| - 2 - Quenching is the problem with marine type bearings cast by Allison's process, owing to variation in section and the fact that heavier sections cannot be cooled quickly. Therefore, it is necessary that bearings should be reasonably uniform in material section. Water quenching may not, however, be satisfactory for alloy steel, such as used on these bearings. This should be investigated. You will remember that best center bearing produced, which went through high speed rig test satisfactorily, was a solid 70/30 lead bronze, which can no doubt be accounted for by increased section of lead bronze, and the fact of being cast in thin steel shell, which would permit of more rapid cooling and would therefore indicate that modified cooling can be applied to centrifugal process. Allison's consider that electrolytic copper, as used for dynamo commutators, would be suitable for bearings. Would you therefore make inquiries from Lucas's with regard to scrap commutator bar cuttings, and whether in the event of this material proving satisfactory by test and analysis, we could obtain their scrap cuttings which would be press shaping scrap. Now that satisfactory tests have been carried out on Allison's bearings, it would appear that tests should proceed on Rg{Mr Rowledge}'s test rig, which would be most suitable for proving clearance, form of lubrication and bearing reliability at higher speeds. Rm{William Robotham - Chief Engineer} and I went over Cleveland Graphite today and whilst we did not see lead bronze production, it was stated, owing to the fact that the plant was not in operation, that lead bronze bearings will be standardized on the majority of American Motor Car engines next year and the necessary equipment for the production of lead bronze bearings on quantity basis is being installed. RHC{R. H. Coverley - Production Engineer} | ||