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).
Failure analysis report on an Allison BZ/L bearing material.
Identifier | ExFiles\Box 115\1\ scan0322 | |
Date | 23th April 1937 guessed | |
Bearing Material. Allison BZ/L. Brinell No. 35.1 Composition. Copper ........ 70% Lead .......... 30% ½% of silver is included in the total. Clearance (cold) when fitted = .0035". Clearance (hot) last check prior to failure = .0045". V.C.M. sleeve. Brinell No. 715. Failure occurred at completion of 4 hour run at 3150 RPM. i.e. 2500 lbs/sq.in. load. Type of Failure. The bearing gave plenty of warning before failure occurred. Many times during the running local seizures took place, sometimes resulting in as much as a 30° to 40°C. rise in temperature being recorded by the thermocouple, but after each of these seizures the bearing recovered without treatment; no solid seizure occurred at all and the bearing was removed on account of it having large area lead wiped. TOTAL RUNNING TIME OF BEARING ..... 39 hrs. 49 mins. | ||