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).
Endurance tests of Hall's solid metal main bearings, focusing on clearance and hammering issues.
| Identifier | ExFiles\Box 115\1\ scan0026 | |
| Date | 27th May 1936 | |
| To Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} c. to Dy.{F R Danby} c. to Mx.{John H Maddocks - Chief Proving Officer} x 1070 Ha/Swdl.{Len H. Swindell}2/JH. 27.5.36. Hall's Solid Metal Main Bearings. Further to endurance carried out on the above bearings we have just completed 30 hrs. with annealed main bearings. The object of the annealed bearings is to run with m/m clearance that is .0025 for the main whereas with the non annealed bearings it is necessary to have an extra clearance of .0005 when fitting. The result of the test shows no improvement in the bearing condition and at the present time we are obtaining such inconsistency of clearances after running, that the .0005 difference in clearance for annealed and non annealed bearings becomes insignificant. With both types of bearings, hammering out has taken place both on the main and big end bearings. This has only occured latterly in an obvious form, as when Hall's solid metal bearings were first experimented with. Several endurance tests were carried out resulting in clearance variation since fitting of only .0001 to .0002 on the big ends and .0005 on the main bearings. In several instances of engines recently run, the bearings have hammered out on the pressure and inertia loading sections of the big end bearings to the extent of .005 on the diameter and the total of the clearance developed between the bearing halves and the liners up to the extent of .006. The same thing also takes place although not quite to such an extent on the main bearings, but in the latter is usually confined to the cap pressure half. | ||