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).
Difficulty with single valve hydraulic shock absorbers due to temperature-induced changes in oil resistance.
| Identifier | ExFiles\Box 179b\2\ img007 | |
| Date | 4th October 1932 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} Hor. c. Da.{Bernard Day - Chassis Design} H.V. Hdy.{William Hardy} ORIGINAL Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}12/AD4.10.32. x.35. HYDRAULIC SHOCK DAMPERS TO H.{Arthur M. Hanbury - Head Complaints} SCHEME 3497. We have encountered a difficulty on the single valve of these shock absorbers. If the resistance to the movement of the damping disc is adjusted so that it will silence the valve when the temperature of the oil has risen to what might be expected on a summers day, then the resistance to movement of this disc is so great when the temperature of the damper has dropped to winter conditions that the effective loading increases very considerably. On our last visit to West WitteringHenry Royce's home town the dampers were set at 90 lbs. ball pin load but were found to be running at the equivalent of 140 lbs. due to this phenomenon. We have carried out a lot of tests trying to strike a compromise for the damping of the valve which will not interfere with the loading but have not up to the present been entirely successful. We think, however, we have a compromise which will silence the valve and will only affect the loads in extreme conditions of cold. However, it is necessary to get a considerable amount of road experience before we can say exactly what amount of damping is required to ensure silence under road conditions. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||