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).
Suggestions for modifying a hydraulic shock absorber valve to prevent oscillation and improve oil flow.
| Identifier | ExFiles\Box 68\2\ scan0115 | |
| Date | 10th February 1926 | |
| To Hs.{Lord Ernest Hives - Chair} from DA.{Bernard Day - Chassis Design} 48520 DA{Bernard Day - Chassis Design}2/M10.2.26. RE. HYDRAULIC SHOCK ABSORBER. X.8520 X.235 One suggestion is that the valve face may be too wide so that when the valve opens there is a sudden increase in its effective area to pressure, and it is lifted beyond the proper point, falling again owing to the increased opening: this might set up an oscillation. Another suggestion is that trouble may lie with the piston type valve. It will be seen that the piston guide of the valve partly restricts the oil outlet going to the low pressure chamber. It is thought that a pressure may be built up by this means, or similar means, in such a way as to carry the valve up or beyond its proper point. To overcome this we suggest that the piston guide should be deeply grooved, perhaps with 3 semi circular grooves such as is usually done in valves of this type. Alternatively there might be a number of grooves as deep as possible. A third suggestion is merely to reduce the length of the piston guide so as to reduce as far as possible the obstruction to the oil passage. We are sending these remarks to R.{Sir Henry Royce}, together with a sketch of a valve designed so as not to have the piston effect. | ||