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).
Summary of test results on pressure velocity dampers, outlining findings and proposing modifications.
| Identifier | WestWitteringFiles\S\June1928-August1928\ Scan026 | |
| Date | 8th June 1928 guessed | |
| contd :- -2- [struck through text] through the straight passages. Summarising the information that we have gained from these diagrams : (1) That the working pressure on the low pressure stroke is only about 50% of that of the high pressure stroke even at low velocities, at high velocities it is even less. Statically it is 80%, therefore this accounts for us always feeling we wanted more low pressure loading than one would imagine from the static figures. (2) This trouble does not occur to the same extent with the pressure velocity dampers, this perhaps accounts for their effectiveness. (3) The pressure velocity dampers give practically the same results as standard for low piston velocities but much greater damping at high piston speeds. (4) The standard damper fills up remarkably well. lost movement is negligible. The cushioning effect is present but is rather less than we previously anticipated. (5) Maximum pressures of 800 lbs/sq.in. do not seem to harm the damper. We feel, as a result of these tests, that it would be advantageous to arrange some velocity pressure increase in the present standard damper piston to increase its effective upward loading. We believe that this would improve the efficacy of the front dampers in dealing with high speed wobbles without impairing the low speed riding of the car to any great extent. Also, at the present moment if some foreign matter lodges under | ||