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).
Modifications to the Spectre Clutch to deal with a needle roller bearing failure.
| Identifier | ExFiles\Box 93\3\ scan0043 | |
| Date | 13th May 1935 | |
| X512 To BY.{R.W. Bailey - Chief Engineer} from HDY.{William Hardy} SECRET. HDY.{William Hardy}1/HP.13.5.35. c. WOF. E.{Mr Elliott - Chief Engineer} HS.{Lord Ernest Hives - Chair} Da.{Bernard Day - Chassis Design} RHO. SpectreCodename for Phantom III Clutch. M.{Mr Moon / Mr Moore} Sch.4491 herewith shows the modifications we suggest to deal with the recent failure of the needle roller bearing at the rear of the clutch. We have been able to much improve the conditions by deleting the ball bearing between the flywheel extension and the casing. Our justification for the removal of this bearing is that we understand that so far it is not possible to distinguish whether the bearing is in place or not and as the difficulty of reliable lubrication is considerable and the consequence of a failure serious, we think that the present indications are that we shall be better off without it. The bearing between the flywheel extension and the clutch shaft is now a ball bearing and can be in a housing which will retain some oil. The use of the Bijur drip plug is continued although we do not regard it as a 100% reliable means of lubrication. Should failure occur the bearing has to make do with what is held in the housing. An alternative is to delete the drip plug and pack the housing with grease as for the flywheel spigot bearing. Oil sealing bearings of the New Departure type and porous cage bearings, as suggested by Ransome and Marles, may be the solution, but our experience of these seems hardly sufficient to justify any reliance being placed on them at this stage. When it is definitely known that a bearing for the crankshaft support can be dispensed with the clutch casing design can be gone over to save weight by deleting some of the bolts and the loose end plate. HDY.{William Hardy} | ||