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).
New scheme for the 3.5 litre Bentley crankshaft and flywheel to prevent them from coming loose.
| Identifier | ExFiles\Box 85\2\ scan0017 | |
| Date | 30th June 1933 | |
| X212. To Hs.{Lord Ernest Hives - Chair} from E.{Mr Elliott - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} By.{R.W. Bailey - Chief Engineer} Sft.{Mr Swift} RHC.{R. H. Coverley - Production Engineer} E.1/HP.30.6.33. Bentley Crankshaft and Flywheel. To overcome the difficulty experienced with the flywheel coming loose on the 3½ litre Bentley crankshaft, we are instructing a scheme with a separate flywheel centre which we would like fitted on the chassis intended for the 10,000 miles test. We have got to accept the first 15 cranks as they are with 8 bolt holes only, but we think with this scheme that the attachment may be permanently satisfactory, and that the increased number of bolts may not be needed. Nevertheless we shall have ready a 12 bolt scheme to be used if necessary. With the separate centre we can use in the existing flywheels by turning out the centre of the web, and the hub bolted to the crankshaft flange will be made 50% thicker than now, namely, .225" instead of .150", while the nuts will be made .325" instead of .2" thick. We wish to lock these nuts by driving a centre punch into the end of the bolt stem in three places to form three little keys. We do not like heavy rivetting at this point as it is impossible to get satisfactorily rigid holding up behind the bolt head. On the 12 bolter scheme where we shall be able to gain still more room we propose to use tab washers additionally under the nuts, but we are expecting that this scheme will not be called for as we anticipate that the intermediate scheme will give satisfactory results. The LeC. number for the latter will be 3549. The separate centre enables us to use a different steel, more suitable for withstanding the flexing of the thin web. E.{Mr Elliott - Chief Engineer} | ||