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).
Modifications and potential issues with the front axle control damper levers.
| Identifier | ExFiles\Box 12\1\ 01-page115 | |
| Date | 1st December 1928 | |
| X. 7420 Hs.{Lord Ernest Hives - Chair} from DA.{Bernard Day - Chassis Design} DA{Bernard Day - Chassis Design}1/M1.12.28. RE. FRONT AXLE CONTROL DAMPER. With reference to Hs{Lord Ernest Hives - Chair}/Rn{Mr Robinson}3/LG13.11.28. and Hs{Lord Ernest Hives - Chair}/Rn{Mr Robinson}3/LG19.11.28., we are not certain what is the actual length of the outside lever. If it is 14" then we think it will not be necessary to modify the SS.{S. Smith} lever shewn on N.Sch. 2635., the proportions of which around the boss it will be seen are less than the standard lever, but if the standard lever is 12" we think it would be desirable to increase the SS.{S. Smith} lever in spite of the fact that the load is better distributed due to the tapered serrations. We suggest that the boss should be increased to the standard diameter, and the radii between the shank and the boss somewhat increased. With reference to the standard lever which broke, we are not sure whether you are convinced that any alteration is necessary, as it seems probable there is something defective in the actual piece. For instance, this lever seems much stronger than the lever inside. If however any alteration is considered necessary then we think that all that should be done is to alter the section from elliptical to rectangular, and increase the radii connecting the shank with the boss by 2 or 3 times. If the state of the material allows a desirable improvement would be substituting tapered serrations for the key, as has been done on SS.{S. Smith} With reference to the inside lever it appears to us that the limits are not correct. The female dimension is .876 plus 2, and the male dimension .875 minus 5., so that the shaft could be 8 thous. smaller than the hole on the extreme limits, and the actual sloppiness is more than this because of the angle of the square. We should have thought that much finer limits were required on this job, and that it would be quite possible to obtain them. There appears to be very little reason why the two pieces should not be size and size since the lever will expand on the square being driven in. If the lever is very slack on the square it seems quite likely that it will be overstressed in tightening up, and so introduce an initial weakness. We suggest that this point should be looked into before the lever is altered, as we still do not understand why the equivalent lever on the rear damper stands up, though it appears to be more highly stressed. DA.{Bernard Day - Chassis Design} | ||