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).
Interference fit and nip allowance for Bentley main bearings.
| Identifier | ExFiles\Box 114\3\ scan0117 | |
| Date | 14th January 1938 | |
| GWH.{George W. Hancock - Head Chateauroux} (K) C. K.{Mr Kilner} (crossed out) C. Rm.{William Robotham - Chief Engineer} (crossed out) BY.5/G.14.1.38. [STAMP] FRANCO-BRITANNIC AUTOS Ltd 17 JANV 1938 12 AVENUE GEORGE V PARIS [/STAMP] BENTLEY MAIN BEARINGS. Referring to Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}3/N.5.1.38. and also to Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}3/MH.{M. Huckerby}19.11.37. circulated under cover of Hd{Mr Hayward/Mr Huddy}/SB.{Mr Bull/Mr Bannister}4/ HR.23.12.37. the matter is not capable of a simple solution as suggested, as obviously shortly all replacement bearings supplied from the Works will have an interference fit. It appears to me that all that is required, in addition to the information referred to above, is to remark that it will be necessary to check the dimensions of the replacement bearings supplied if these have an interference fit, then a nip allowance of .001 per side is all that should be permitted, as the interference fit is arranged to take the place of .001 out of the original K.{Mr Kilner} allowance of .002 per side. It should therefore be clear that it is necessary to check the replacement bearings, if these are undersize then the original nip allowance of .002 must be allowed. If the bearings are supplied with an interference fit then .001 per side will give precisely the same conditions as with the earlier bearings undersize, and a .002 per side nip allowance. BY.{R.W. Bailey - Chief Engineer} [Signature] | ||