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).
On the design considerations and trade-offs for using articulated rods on the Phantom III engine.
| Identifier | ExFiles\Box 93\1\ scan0128 | |
| Date | 13th February 1937 | |
| Rm{William Robotham - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Smth. Rm{William Robotham - Chief Engineer}/Smth.13/M.2.37. Articulated Rods for Ph.III. (1) They would cost less than the standard ones. Max. estimated saving £5 per set. (2) The articulated rod imposes a whipping stress on the master rod. If we keep the existing shank section this would amount to ± 12 tons per sq.in. which is as much as the maximum inertia compression stress due to the reciprocating masses on the master rod and occurs at about the same instant. The lower end of the shank would hence have to be stiffened up and the rods would probably weigh asmuch as the present ones. (3) The stroke of the articulated bank will be about .250 longer than the other. No unbalance effects are likely to result from this. The comp. ratio can be corrected by shortening the articulated link by .040. (4) If the present big end bearing diameter is retained the outside of the liners on the articulated side will have to be gashed to a depth of .050. If this bank is on the trailing side the oil consumption should not suffer. Rm{William Robotham - Chief Engineer}/Smth. | ||