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).
Manufacturing difficulties, performance, and potential improvements for shock dampers.
| Identifier | ExFiles\Box 28\1\ Scan142 | |
| Date | 5th December 1929 | |
| To Da.{Bernard Day - Chassis Design} From Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} X832. Hs{Lord Ernest Hives - Chair}/Rnl/WJ.5.12.29. SHOCK DAMPERS. With reference to Da{Bernard Day - Chassis Design}3/M29.11.29. (1) We are not having very great trouble with wear on any portion of the damper. The main lever bearings are standing up quite well. We should not say that the ball bearings are any better than the plain bearings as we have had half a dozen failures of the former. The most difficult feature of the dampers to manufacture are the links. These have a tendency to sieze up as they have to be fitted with such a fine clearance and also in rolling the ends over the pins get distorted. This we have previously pointed out. Another feature is that when the links are made with so little side clearance (we stipulate a maximum of .003) it is most difficult to line up the lever shaft and piston. (2) We have not had any cases of knocking after fitting links tightly and drilling the H.P. valve. However we have had no shock dampers so treated in service for longer than a year as yet. As we are not running any drilled valves on Phantom ll this is not a universally applicable cure. (3) Production much prefer the lever and shaft made separately as on Phantom ll. They consider that a Woodruffe key and taper would be preferable to the present splines. They are very pleased with the two externally adjustable valves, they would like to have dampers that would be the same for 40/50 and 20 HP as the duplication of tools and jigs is very costly. Summarising the troubles existing. Lubricating the shaft main bearings appears to have improved wear as troubles at this point are not frequent. The only justifiable complaint appears to be the difficulty of manufacturing the links owing to the fine limits that have to be employed to obtain silence. Phantom ll dampers have given very little trouble but we have not been running such high loads on our 10,000 miles test as appears to be necessary on the Prince of Wales and other fast cars. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||