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).
Design improvements and failure analysis of hydraulic shock dampers.
| Identifier | ExFiles\Box 68\2\ scan0134 | |
| Date | 2nd March 1926 | |
| To DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} Hs.{Lord Ernest Hives - Chair} } FROM R.{Sir Henry Royce} c. to CJ. BJ. RG.{Mr Rowledge} c. to E.{Mr Elliott - Chief Engineer} X8520 R1/M2.3.26. RR. HYDRAULIC SHOCK DAMPERS. X.235 X.8520 The strengthening of the two parts that have failed is obvious and easy. The high pressure valve at the end e is better, the spring over the valve should be made right for 75/85 lbs. and have no loose packing. There should be very little or no space above the small ventilation and restriction hole. I think the passages should rise until the discharged air and oil pass the nonreturn valve which is necessary in any case, or air will be drawn in instead of oil - viz: the bottom valve. After the ball valve the passage can descend. This seems to save head room and parts. SEE ORIGINAL FOR SKETCH+ The other point is the filter. This should guard all valves and pistons. It seems better at the bottom, and should be attached to the bottom plug so that it will come out with the plug. With such a scheme the apparatus cannot be filled without the filter being in place, and the oil will go in quickly at once and be filtered slowly. It may require some more refinements but try it simply without much capacity or vent in the other side of the filter from the filling side though I fear that it may require some capacity and vent to the atmosphere because the small intake valves will want to snatch a little oil quickly, and if it has to pass the filter in small jerks it may takelong to fill the working spaces, but I should be satisfied if the reservoir was filled once and the car run on the road, and then it is again filled up after having charged the working parts. On further examination I cannot see how we can protect the central piston from grit, unless we get this on the past side of the filter. This suggests 2 reservoirs or 2 filters, or we chance any trouble here for the time being; everyone else does - Houdaille etc. One thinks of putting the top joint higher and putting a gauze all over in the joint to catch the ingoing dirt. The gauze ought to be about 100 mesh each way (10,000 per sq.in.) but you should try what is practical and effective. contd :- | ||