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).
Various design proposals and fixing methods for piston pins.
| Identifier | ExFiles\Box 10\1\ 01-page63 | |
| Date | 5th September 1923 | |
| To Rg.{Mr Rowledge} from R.{Sir Henry Royce} c. to CJ. HS.{Lord Ernest Hives - Chair} X685 R1/M5.9.23 RE. PISTON PINS. X.4603. X.685 With reference to piston pins I think it is undesirable that the piston pin should have a head because of the difficulty of getting exact parallel grinding unless we can run over each end of the pin. We have the impression at WW. that for aero engine work it would be safer to let the pin be free in the piston which we think would cure various troubles experienced with piston pin fixings both in cars and aero engines. The third point is that in spite of what the Derby Works say I believe the best practice will be to have a floating bush in the little end of the connecting rod in spite of the fact that the little end of the connecting rod is not casehardened. I would like you to have these suggestions tested out, or tell me your reasons for definitely disagreeing with them. As regards car work we are suggesting a trial of a piston with screws used in the very old fashioned way but of very different proportions, and this is shewn on Mr. Elliott's drawing - LeC.1756. We are also proposing to hold the piston pin by means of 2 bolts passing through the crown of the piston and through the centre line of the piston pin, as shewn on drawing LeC.1758. We would like these schemes tested as soon as suitable pistons can be made. R.{Sir Henry Royce} | ||