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 and production considerations for hydraulic dampers.
| Identifier | WestWitteringFiles\V\October1930-February1931\ Scan378 | |
| Date | 25th February 1931 | |
| DA{Bernard Day - Chassis Design}/HDY.{William Hardy}) FROM R.{Sir Henry Royce} HS{Lord Ernest Hives - Chair}/RM.{William Robotham - Chief Engineer} ) (At Le CanadelHenry Royce's French residence.) BY.{R.W. Bailey - Chief Engineer} ) C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} E HYDRAULIC DAMPERS. x235. I think we ought to know what we intend to make for our general production. It must be one model for both front and rear of P. 2. and J.{Mr Johnson W.M.} 3., also if possible for left and right side of each car. We could do the left and right if the damper body were reversible end for end - i.e. valves on the side would perhaps make a more symmetrically reversible pattern. Since we intend to have the lever detachable (with some trouble) by wheel puller it might be put on slowly tapering serrations which are fairly easily cut on the shaft and might be made in the lever, thus - A hole bored and broached parallel, a taper serrated drift representing the shaft is made of tungsten type steel (i.e. hard when it is hot,) and the lever heated suitably, say about 500°C., and the drift pressed in to make an exactly sized slowly tapering hole in the lever which is forced on the shaft by the usual nut. It would take a good wheel drawer to pull it off in case the gland requires packing. I feel sure we ought to be able to do this after removing the lever by undoing 2 nuts, (not a pressed in gland) as no-one knows how to get it out. The piston is to be made like the sketch in my last memo. - i.e. our version of Delco. We could have the replenishing valves in the piston if we had a screw plug at each end of the bore, but still we could not examine unless we removed the damper from the car. A decision would depend on two points - if the design of the body presented any difficulties in getting in the replenishing valves, and whether the inertia was really of value. One imagines the latter is not much because the pistons motion is usually very slow and ordinary inspection looks very difficult. The internal lever can be treated two ways - solid like our double vertical and Delco, or pressed on fine parallel serrations as suggested in my last, and used in Delco external lever. The worst point about the detachable lever is that it requires some positive means of keeping on for fear it worked loose: it might then work out. (1) | ||