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).
Engine bearing test #6, detailing the performance of a new Allison center main bearing specification S3-30.
Identifier | ExFiles\Box 173\2\ img232 | |
Date | 22th February 1934 | |
19 February 22, 1934. ROLLS ROYCE ENGINE BEARING TESTS (Continued) Test #6 A test was run this date on a new Allison center main bearing specification S3-30 (70 Cu, 30 lead, 1% silver) as a further test of bearings from different casting heats. Other bearings used (intermediate and end) were the same bearings as were used on #1, 3, and 5 tests. All bearings used Rolls Royce type grooving and lubrication. Crankshaft used was #4, previously used on tests #2, 4, and 5. A slight amount of boosting was required of the auxiliary oil pump to maintain 68-70 lbs. per sq.in. oil pressure at 3500 R.P.M. The bearings were run-in and tested at 3500 R.P.M. under as nearly the same conditions as could be maintained to #3 and #5 tests. The test consisted of 15 minutes at 3500 R.P.M., 20 diving tests of 30 seconds at 3500 R.P.M. and 1 minute at 2250 R.P.M., followed immediately by 15 minutes at 3500 R.P.M., a total of 40 minutes at 3500 R.P.M. No failure occurred. The bearing temperature averaged about 117° C at 3500 R.P.M., or 12° higher than on #3 test with a bearing of similar composition, and 3° higher than on #5 test with the 60% Cu, 40% lead composition. The torque load averaged slightly higher than on #5 test, but was # less than #3 test. It appears likely that the differences between the three tests, #3, 5, and 6 are within the experimental limits of the instruments and set-up since there is no consistency of trend between the various tests. | ||