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).
Issues with the New Phantom Spring Drives seizing and providing assembly instructions to prevent it.
| Identifier | ExFiles\Box 65\4\ scan0242 | |
| Date | 27th November 1925 | |
| 78020 To Hs{Lord Ernest Hives - Chair} from RHC.{R. H. Coverley - Production Engineer} RHC{R. H. Coverley - Production Engineer}15/EE. 27.11.25. RE NEW PHANTOMCodename for PHANTOM I SPRING DRIVES With reference to Spring Drive which seized on Crankshaft taper. This was corrected and made good fit on taper and, since testing, has been examined on several occasions without showing any further signs of seizing. It is fairly obvious that this trouble is caused through bad fitting. Whilst it might be advantageous to fit a wider key to provide better location for Spring Drive centre, this trouble will still exist unless workmanship is good. We do not consider that modifying the tapers would help in the least. It is apparent by the tests just carried out that, providing the job is done properly with taper fits in accordance with existing drawings Spring Drives are alright. There are several points in the assembly which should be carefully watched. Firstly - before key is fitted there should be a slight flat filed across the top of the keyway, so that in case the metal is burred or raised when the key is fitted, this will not prevent the Spring Drive seating on its taper and care should be taken that the top of the key is clear of the slot. Secondly - It is important that the face of the Retaining Nut and the face of the Spring Drive centre which makes contact with the Retaining Nut are perfectly square and flat. Thirdly - When locking up Retaining Nut if the Hexagon on Lock Plate and Nut do not coincide, Nut should be hammered up until they do. It is reasonable to suppose that difficulty has been experienced in this direction and to get the required setting the Nut has been loosened to suit. RHC.{R. H. Coverley - Production Engineer} | ||