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).
Methods for improving chassis rigidity to reduce vibration and shimmy.
| Identifier | ExFiles\Box 137\4\ scan0311 | |
| Date | 9th April 1931 | |
| To R.{Sir Henry Royce} From E.{Mr Elliott - Chief Engineer} Copy to SG.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} Da.{Bernard Day - Chassis Design} X634 E1/T9.4.31. ----------------- FUSS, ROAR, BOOM AND SHIMMY. ----------------- Assuming that no one would wish to use the engine for stiffening the frame, if it could be dispensed with, the deeper side channel offers a possibility of solution along these lines. We would suggest that the special significance in the use of the deep side channel lies in its ability to utilise the stiffness of the body to control the front axle. The use of deeper side members should add particularly to the torsional rigidity of the chassis frame, but when the body is mounted a different state of affairs comes into being. The Maybach might be quoted in support of this argument, both the examples tried by us being reported as free from shimmy. On our own P.II. chassis, a frame with side channels of double the present thickness made with existing dies, appears to be a considerable improvement. Again, as negative evidence in favour, experiments to stiffen the front of the frame with a rigid cross using the existing side channels proved of very little benefit. Assuming body stiffness to preponderate, an increase of 50% in frame depth should increase the rigidity of the forward part of the frame about three times. E.{Mr Elliott - Chief Engineer} | ||