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).
Breakage of a Bentley crankcase central main bearing and proposing a design modification.
| Identifier | ExFiles\Box 132\3\ scan0010 | |
| Date | 25th October 1933 | |
| X216 To WOR.{Arthur Wormald - General Works Manager} from E.{Mr Elliott - Chief Engineer} E11/HP.25.10.33. c. Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} Sft.{Mr Swift} RHC.{R. H. Coverley - Production Engineer} Bentley Crankcase. The breakage of the central main bearing on a test bed Bentley crankcase shows that we have definitely a weak spot at this point. There is a sharp corner where the crankcase has been milled for the caps to fit on, and it is from this corner that the fracture has started culminating by tearing out a piece of the crankcase material containing the stud. There is no doubt that the central main bearing carries a very much bigger load than any of the others even with the degree of counter weighting we are using, and we think the best policy would be to use the through bolts for this bearing. At the same time we wish to introduce a decided radius in the corner where the fracture started. We should like instructions to be issued for altering the crankcase pattern forthwith so that we can use bolts on this bearing as early as possible. It is a modification which is obviously going to be stronger than the present design. E.{Mr Elliott - Chief Engineer} | ||