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 criticisms and requested modifications for the 'Buzzard' and 'Vulture' rear axle.
| Identifier | WestWitteringFiles\E\June1920\ Scan42 | |
| Date | 2nd July 1920 | |
| To DA.{Bernard Day - Chassis Design} from E.{Mr Elliott - Chief Engineer} Copy to CJ. HS.{Lord Ernest Hives - Chair} BT.{Capt. J. S. Burt - Engineer} EFC. [STAMP] D 2 JUL 1920 ORIGINAL [STAMP] RECEIVED 5 E5/G30/6/20. X.3832. X.3873 "BUZZARD" AND "VULTURE" REAR AXLE. With reference to your N. scheme 339, would you kindly note the following points of criticism, sent in accordance with Mr. Royce's wishes:- (1) It is thought that the position of the oil filler plug is rather inconvenient, as to get at it will require removal of the back seat cushions and boards. An idea previously entertained was to have the oil filler on the torque tube in such a position that it could be easily reached by lifting the floorboards in the rear of the car. Mr. Royce does not wish any alteration made, however, but would like this point to be kept in mind for future reference. (2) The right hand portion of the differential cage within the ball journal and for a length of about 2 1/4" towards the crown bevel should be thickened up by adding material in the bore. The wheel driving shaft would still be withdrawable through the hole since it has to pass through the bush on the inner end. (3) It is noted that the angle of obliquity of the differential bevel teeth is given as 20°. This angle may require to be larger, in accordance with the criticism made on the 20 H.P. differential bevels inspected at West WitteringHenry Royce's home town. (4) The square corner preventing the right hand axle tube bolts from turning should be cancelled and replaced by a larger radius formed in the natural corner of the axle case. The bolts should be prevented from turning by a cylindrical flange added to the outer diameter of the plate which prevents the bolts from moving inwards and also by making the flange of the crown bevel thrust washer housing large enough in diameter to touch the bolt heads. The idea of using two devices is that the former will keep the bolts in their correct position always, but is not strong enough to resist the torque that would be imposed by screwing on a nut with a tight thread. The latter feature, to prevent turning, will resist any torque that is likely to be imposed, but is not always in position to prevent the bolts from turning, although it will be there when the nuts holding on the axle tube are tightened up. (Contd.) | ||