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).
Inconsistent and unsatisfactory results of white metal bearing tests.
| Identifier | WestWitteringFiles\P\October1926-November1926\ Scan109 | |
| Date | 12th November 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rml c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to EY. ORIGINAL Hs{Lord Ernest Hives - Chair}/Rml/T12.11.26. WHITE METAL BEARING TESTS. X4633 We are not very satisfied with our white metal bearing test results. Whilst we can establish general results by doing a large number of repetition tests, we are always getting bearings which are exceptions to the majority, and either support considerably greater or smaller loads than the average. Also the performances of the bearings vary from batch to batch. The general rule is, therefore, at present of doubtful value if bearings behave in service as they do on the testing rig, because the exceptional bearing will let the designer down every time. We are therefore, in conjunction with the laboratory, attempting to get some consistent bearings and at the same time taking every precaution on our testing rig, including the use of oil purifiers; and until we succeed in reducing the extremes between good and bad bearings, consider that the tests we may make are only of comparative value. We have taken some temperature figures on running bearings by means of thermo-couples, the results of which we attach. It will be observed that one bearing may run at 30° higher temperature than another at the same speed, and yet both fail on the same load. (R.R.'). Also that the temperature at which the bearing fails is not within 75° C of its mean running temperature. Contd. | ||