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).
Damper indicator diagrams, customer complaints about hydraulic dampers, and future development plans.
| Identifier | WestWitteringFiles\V\December1930-February1931\ Scan087 | |
| Date | 3rd January 1931 guessed | |
| - 4 - INDICATOR DIAGRAMS. The figures in the circle represent the ft.lbs. of damping obtained from the damper expressed as a percentage of the ft.lbs. of damping expected from the static ball pin loads. Where there is an increase of pressure with velocity it is possible for the diagram to shew over 100% because the dynamic maximum load obtained is much greater than the static load. The areas given in sq.in. are the actual measured areas of the diagrams and can be used for direct comparison of the various conditions. It is interesting to note on Sheet II. Fig.4 that as the loads on the front damper are increased the disparity between the high and low pressure sides increase also. QUARTERLY COMPLAINTS. We must have somewhere between 15 & 20,000 horizontal type of hydraulic dampers in service. On some cars the owners have repeatedly had their shock absorbers changed. A spring loaded piston on the same lines as those on the new double damper would, we consider, cure 30% of the complaints of knocks. Would it not be possible to produce such a piston to satisfy existing customers, instead of re-fitting links which are not likely to be a permanent cure ? FUTURE DEVELOPMENT. We have still to find out why the horizontal damper is inefficient over high frequency small movements. Hs.{Lord Ernest Hives - Chair} has seen diagrams taken of the 'Delco' shock absorber in their factory which shew that this difficulty does not appear to exist. Now we have one of their dampers on test we should be able to conform or refute their assertions. We are preparing a report on the 'Delco' damper. We also want to prove if we loose any efficiency due to spring in the casing. In spite of our own views that damping should start as soon as the axle begins to move, we have to remember that Springfield are producing cars with wonderfully good riding qualities (agreed by Hs.{Lord Ernest Hives - Chair}) with the same parts as we use and are criticizing. therefore we may be over emphasizing road holding requirements. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||