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).
Technical notes on shock damper design, materials, and associated components.
| Identifier | WestWitteringFiles\V\March1931-September1931\ Scan060 | |
| Date | 18th March 1931 guessed | |
| (2) Referring to the leak past the valve, I think we ought to agree that this should be a plain round hole of some size that can be easily produced, and not alterable, because I have often pointed out the danger of this being too large or wrongly adjusted, rendering the shock damper ineffective and the car dangerous, or inclined to make passengers seasick. The leak should allow of the full valve pressure for body movements of about 60 per min. over say 2" stroke. Now I have pointed out that we must allow the axle to move at high speed with as little increase of pressure as possible - i.e. we do not want to damp the high speed movements of the axle any more than the slow speed and this is one of the features and advantages of the solid friction type Hartford and the great superiority of the relief valve over the restricted passage. If we want to make any changes between cars travelling at high speed and low speed it certainly should be in allowing the relief valves to open at lower pressure - i.e. say 50 lbs. ball load at 30/40, and 100 lbs. at 50/60., and 150 lbs at 80/90. It is for this reason we ought to try if the single double direction valve is good for ordinary work because it is a type that can easier be controlled. WEARING SURFACES. It seems that to stand the heavy loads, poor lubrication, and grit, we must make the cam and pads, balls and their pads, and the shaft, as hard as possible. I have tested many parts by different makers and find that parts supposed to be hard often seem to file fairly easily as if they had a soft skin. I hope we shall be able to get these parts extra hard, perhaps nitro-hardened, but I do not know if this system is convenient for a large number of small pieces. It is generally agreed that C.H.N.S. does not give so hard a surface as unalloyed steels. LOVEJOY SERRATIONS. These appear to be made by knurling the shaft, hardening the same and pressing it with a powerful press into a smooth bored hole in a soft lever. This sch. would do for our internal, and the outside might have a milled taper and hardened with the shaft and pressed into a plain taper bored hole in the lever. REFILLING THE DAMPERS. Don't forget the providing of pipes to the dash: failure of present valves are probably mostly due to dirt getting in while refilling. SPLIT PISTONS. Mr. Hardy noticed that we might get caught by the oil pressure on the stud ends: perhaps a cap should be used. R.{Sir Henry Royce} | ||