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).
Performance and development of hydraulic dampers.
| Identifier | ExFiles\Box 179b\4\ img034 | |
| Date | 12th April 1933 | |
| To Hdy.{William Hardy} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Ha/Rm.{William Robotham - Chief Engineer}1/BE12.4.33. HYDRAULIC DAMPERS Y 235 With reference to your HDY{William Hardy}1/M18.3.33. Attached is a report which shews how we can prevent recession by means of the non-return valve and small by-pass as suggested by R.{Sir Henry Royce} Perhaps you will have the opportunity of discussing the results with R.{Sir Henry Royce} when you have digested them. Recently, we have been endeavouring to get a good ride with the new dampers utilising them as a fixed load instrument. The tests we have made have convinced us that we cannot stand as much pressure velocity increase with load as we have with the present small valve. Even by resorting to drilling, we cannot get a comfortable low speed ride with these dampers. We are therefore concentrating our energies on the large diameter valve. There is a possibility that we may be able to silence the valve without an appreciable length of taper seat. In any case, as we reduce the pressure velocity effect, so we decrease the effect of recession. With reference to your query re the lag in control with decreasing pressure, we actually find that the lag in the decreasing direction does not worry us very much, though the actual figures taken on indicator diagrams are appreciable. The attached report gives you the rig figures. On the road the ride seems to begin to soften immediately the hand control is moved. We send you herewith, copy of R.R. Sch.363 as requested. One advantage of the heavy internal spring is that it reduces the variation likely to occur between different dampers due to the fact that the bellows supplied have a variable rating. We think that increasing the pump delivery would undoubtedly help us in reducing the lag when pumping up the damper load. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||