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).
Tests conducted on hydraulic shock dampers to improve car riding stability and control.
| Identifier | WestWitteringFiles\R\2October1927-November-1927\ 141 | |
| Date | 16th November 1927 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to BJ. Wor.{Arthur Wormald - General Works Manager}✓ c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer}✓ OY. ORIGINAL Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}1/LG16.11.27. HYDRAULIC SHOCK DAMPERS. X235 X7410 We obtained some figures for the front axle velocity on the road when fitted with hydraulic dampers. The tests were not very easy to make nor very accurate but they clearly indicated that the axle movement was very much slower than we had previously imagined. The rear axle attained a velocity of about twice that of the front axle but owing to the longer lever to the shock damper, the maximum piston velocity remained about the same. As a result of these tests we concluded that we could improve the car riding by increasing the pressure-velocity factor of the shock absorbers while somewhat decreasing the fixed load at which the valves opened. The object of this was to retain the present low speed riding comfort of the car while increasing its stability and controlability at high speeds. We thought initially that if this pressure-velocity factor was increased by merely forcing the oil through a narrow passage, its value would vary widely with the oil viscosity. We therefore carried out tests with various types of passage as indicated in graphs. 1 and 111, some of which (a) were arranged to produce maximum turbulent flow. We found, however, as shewn in graph.111. that a narrow passage gave a pressure rise that was practically unaffected by the oil viscosity which could exist under our car working conditions i.e. contd :- | ||