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).
Observations on the re-design of horizontal type hydraulic dampers, discussing pistons, valves, and oil/air separation.
| Identifier | WestWitteringFiles\V\October1930-February1931\ Scan381 | |
| Date | 26th February 1931 | |
| R.{Sir Henry Royce} FROM DA{Bernard Day - Chassis Design}/HDY.{William Hardy} Copy to - HS.{Lord Ernest Hives - Chair} ORIGINAL HYDRAULIC DAMPERS. DA{Bernard Day - Chassis Design}/HDY{William Hardy}1/M26.2.31. X238- With reference to R1/M7.2.31., and the proposed re-design of the horizontal type dampers we give below our observations *PISTONS. We prefer our scheme with the pistons fitting long bolts to that of the Delco as the cross winding seems to be less serious in our case. VALVES. We are not at all certain that the Delco valves have features worth copying until more experimental work has been done on this subject. On the other hand the new valve schemed for the remote control with single seating and spring seems to have some very definite advantages:- (1) It cannot, as the result of lag, be slammed onto its seating by the reversed oil pressure, but on the contrary, it is merely prevented from reaching its seating and should therefore make no noise as the result of sudden reversals of motion. (2) The absence of hammering enables a knife-edge seating to be used with consequent freedom from trouble due to foreign matter. (3) Damping control can be applied to it with the minimum of complication. With regard to the piston type valve it may be of interest to note that it can be so reduced in size without becoming too small, that the lost motion is negligible. For example a valve .312 bore, .150 thickness, would allow .04" undamped movement each side of normal with a 13" lever. SEPARATION OF AIR FROM THE OIL. We think that the advantage found to exist on the H.P. side of the vertical damper in the separation of air without a separate leak is partly brought about by the transfer oilway being some distance below the piston, and consequently the oil is not much disturbed where the air is collecting for escape. We can repeat this to some extent on the horizontal damper by placing the passage some way down. LUBRICATION OF MAIN SHAFT BEARINGS. We have sent through a patent drawing of this scheme. It may be all that is needed to make the horizontal damper as satisfactory as the double vertical damper should be in avoiding knocking. [Handwritten note at bottom] letter reference received R1/M 29-2-31. We agree that on the pins (1) the Delco piston is much | ||