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).
Suggestions and issues related to shock damper design, including valve oscillation and air trapping.
| Identifier | WestWitteringFiles\T\March1929-December1929\ Scan308 | |
| Date | 13th December 1929 | |
| BY.{R.W. Bailey - Chief Engineer} FROM DA.{Bernard Day - Chassis Design} Copy to SG{Arthur F. Sidgreaves - MD} Copy to HS.{Lord Ernest Hives - Chair} ORIGINAL SHOCK DAMPERS. DA{Bernard Day - Chassis Design}2/M13.12.29. +5520 x7520 Herewith we send N. schs. 2996/7., shewing a suggestion for providing a small degree of free motion in the shock damper by means of small air vessels inside the pressure chambers. N. sch. 2996. shews what we suggest as a way of making a quick test on an existing damper, and R.{Sir Henry Royce} would like this to be done at once. N. sch. 2997. is intended for the purpose of taking out a patent, which should be done in the name of Mr. W.G.Hardy. With reference to the principle of this device we are aware that we have had air in the shock dampers before and have found it detrimental, but we suggest that the design of the valve with piston extension, shewn on N. sch. 2085. is probably very different as regards disposition to oscillate compared with the new proposal. We see however that there is a possibility that the valves will oscillate with these air vessels. If so we suggest that the air release slot on the stem of the valve should be reduced to put in some damping. A narrower valve seat would also probably help. If neither of these is effective we can make some further suggestions for damping. If there is a hole drilled in the cylinder casing to the bottom of the valve stem it will be desirable to plug this up should valve oscillation develop. On Phantom 2. front shock dampers it is known that there is a small quantity of air trapped on the high pressure side above the low pressure valve. DA.{Bernard Day - Chassis Design} | ||