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).
Issues with Bentley III front shock dampers and proposing experiments for improvement.
| Identifier | ExFiles\Box 99\3\ scan0080 | |
| Date | 18th May 1938 | |
| 442 To HPS{Horace Percy Smith - Experimental Factory Mgr}/W.Bell. from Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} c. Rm{William Robotham - Chief Engineer}/D.Clapham. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale}1/MH.{M. Huckerby}18.5.38. BENTLEY III FRONT SHOCK DAMPERS. The above dampers have given a lot of trouble on the bump test rig. The chief sources of trouble are the pins, which move sideways, and either score the cylinder wall or scrap the inter lever, and the links, which seem to tighten on the pins. We think it important to test the dampers on the rig under a high load because the maximum loads are apt to occur on a car when it is driven out of a garage on a cold morning down a rough road, before the oil in the damper is warm. On the rig, unless the load in the dampers is high, such conditions are not reproduced. The best oil to use in the dampers is Shokol. We think the following experiments should be tried:- (1) Very high interference between the pins and the piston or inter lever. This will necessitate a special support to enable the pin to be pushed in. A pin hard all over can be used. (2) The links can be made of a high brinell carbon steel, or possibly cast iron. (They can be square section throughout if necessary). (3) The gudgeon pins can be drilled in the centre before hardening the links can be drilled from end to end and a pin passed through all three and rivetted. (4) Other experiments may occur to us as the tests proceed. We, of course, intend to continue running the bump, in parallel. We realize that the bump is a drastic test but we find that unless most chassis components can stand 30 hours on it that they will break in a 15,000 miles road test. We do not see that the dampers are any exception. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} | ||