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).
Theoretical and practical development of silent pistons.
Identifier | WestWitteringFiles\D\October1919\ Scan13 | |
Date | 1st October 1919 | |
To BN.{W.O. Bentley / Mr Barrington} from R.{Sir Henry Royce} Copy to Gd. EH. X3746 ORIGINAL RE SILENT PISTONS. R2/G17/10/19. You will remember that during your visit here, it was definitely concluded that if we could get the piston to stay against the wall of the cylinder from which we derive the driving torque, a very silent piston could be obtained, perhaps altogether quieter than anything we had experienced that was safe. I suggested a pad with a spring, then a plunger with oil pressure, because the latter would be so safe as the lubrication and load come on together. I scarcely thought at the time the scheme was simple enough to be practical, but suggested it would be instructive and worth trying. A good time elapsed in trying this, but it is now reported promising by Mr. Hives. Mr. Elliott had been instructed to arrange a drawing so that the oil passage was open only during the time the piston was on the power side of the cylinder. Owing to the four-stroke cycle this is not quite as simple as it might be, and suggests that to be certain to hold the piston up we may want spring pressure as well as the oil pressure by the ram (possibly also a back pressure valve of the reed type) or a combination of the fewest of these parts which are found to reliably perform the function. If it is thought worth while, we have here at least in theory a piston which will never knock however clear, and should minimise the wear of the rings in their grooves. It should also be very gas tight, and I hope the matter will be pushed on (Contd.) | ||