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).
Report page detailing modifications to shock dampers and the methodology for testing their efficiency.
| Identifier | WestWitteringFiles\Q\2April1927-June1927\ 151 | |
| Date | 1st April 1927 guessed | |
| contd :- -4- give soft riding at slow speeds, while for speed enthusiasts they are best supplemented by Hartfords to damp out the small axle movements that are hydraulically comparatively unrestrained when travelling fast on a good road. The low pressure side of the dampers is automatically provided with greater cushioning than the high pressure side due to the air release hole which is now .024" in dia. This hole was enlarged to eliminate an hydraulic knock and the low pressure springs have been strengthened up accordingly so that the effective load on the low pressure side remains the same for all but the smallest axle movements, while the cushioning is increased. (C) METHOD OF MEASURING SHOCK DAMPER EFFICIENCY. In order to investigate the behaviour of the damper under various conditions we fitted a case with the apparatus described in para. (A), with a maximum reading pressure gauge in each end provided with a non-return ball valve, and with a thermo-couple in contact with the working oil. We were thus able to study the loss of effective stroke under various ranges of piston velocity, temperature and valve pressure; the increase in effective damping with piston velocity, the effect of temp: on this increased damping, and the cushioning occurring in the damper previously described. (D) REDUCTION IN EFFECTIVE STROKE DUE TO EXTREME CONDITIONS OF SPEED LOAD OR TEMPERATURE. Graphs 11. and 111. shew how little the RR. damper is affected by high speeds, loads and temperatures. Practically speaking, the lost movement under contd :- | ||