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).
Design and manufacturing specifications for the Wraith II back axle.
| Identifier | ExFiles\Box 7\3\ X 602 Axle Rear-page29 | |
| Date | 6th November 1936 | |
| +664 Gry.{Shadwell Grylls} 602 PPS C.C. to. Dr. KHC. Rm.{William Robotham - Chief Engineer} Rev. E/HDY.{William Hardy}3/HP.6.11.36. Wraith II Back Axle. We send herewith N.Sch.4944 showing the axle tubes, shafts, hubs and jack brackets for the 25/30 HP. axle centre when used temporarily for this car. We are proceeding with the design of a new axle centre casing to suit the 8/37 ratio 1.625" hypoid gears to N.Sch.4831. We do not expect to have to appreciably alter any of the pieces shown by N.Sch.4944 when they are finally used for the 8/37 centre casing. The axle tubes are to be made from Weldless 3½% nickel steel tube to R.R. Specification No.2063 by Messrs. Tubes Limited. The question of cost has been gone into by Roy.{Sir Henry Royce} and is, we understand, agreed at 16/3 each plus 2/2 for heat treatment. The tubes are to be machined all over on the outside with the exception of a short length unmachined, as indicated. The parallel bore at the outer end will be machined, and the spigot for the centre casing, but otherwise the inside will not be machined. The jack bracket is a mild steel stamping, and is secured to the tube by a number of screws and by sweating with solder. It is thought that the use of solder will avoid the necessity for accurate machining of the tube, and the bore of the bracket to get agreement between the tapers. The exact lateral location of the jack is unimportant. The Gits seal is placed in the hub, as with the axle shaft solid with the driver it would be liable to damage by the shaft serrations when inserting the shaft if placed at the centre casing, as on our standard axle. E/HDY.{William Hardy} | ||