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).
Analysis of bearing and camshaft bush performance and condition following engine testing.
| Identifier | ExFiles\Box 115\4\ scan0111 | |
| Date | 10th September 1940 guessed | |
| - 2 - The centre bearing appeared to be in the best condition, other bearings generally looked to have too much barrelling although some showed signs of break up near both bearing edges. Fretting on the backs of the inserts was not excessive indicating correct 'nip'. Several bearings had 'picked up' portions of the white metal which had broken away. Connecting Rod Bearings. (a) Inner - All twelve halves showed signs of white metal break up adjacent to the joint face on the side opposite the tang. The break up spreading over a diameter of approximately 1/2" and the broken away portions being carried round to be picked up by other parts of the bearing. Bedding fairly even on all bearings. (b) Blade Rod. - all bearings in satisfactory condition. Camshaft Bushes. For the most part these were in good condition and it was difficult to see that they had been run but several showed signs which previous experience has shown to be the forerunner of break up on extended running. CONCLUSION. 1. Engine tests have confirmed rig experience that the Vandervell tri-metal bearings are unable to withstand the severe loading conditions imposed in an aircraft engine. The loading in such a case is much more severe than that represented by theoretical consideration of gas and inertia loading, and may be due in a large extent to the deflection of crankshaft and crankcase on example of this being the difference of 100% in load capacity shown by similar bearings tested on the crankcase rig and on the single panel rigs. 2. Blade rod bearings without flanges appear to be giving satisfactory service and adoption of this design would mean a considerable saving in manufacturing time and cost. Similar bearings in our lead bronze are now being produced in the Experimental Department to gain further experience. 3. Further experience of the camshaft bushes is required before they can be considered satisfactory. Their advantage over shafts running directly in the RR.56 bracket is doubtful. LOV{Mr Lovesey}/AT. | ||