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).
Requirement and effectiveness of torque reaction dampers for the Peregrine engine mounting.
| Identifier | ExFiles\Box 2\10\ 10-page06 | |
| Date | 13th October 1932 | |
| X122 To R.{Sir Henry Royce} from R.{Sir Henry Royce} c. SG.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} Ph. By.{R.W. Bailey - Chief Engineer} Es. re Peregrine Engine Mounting. To determine whether rigidly mounted torque reaction dampers are required or not on Peregrine, we have a pair of these rigged up to Leo.3219 (blueprint attached) on one of the new chassis. This is only a temporary mounting direct from crankcase to frame, but it represents our normal practice as on P.II and the 20/25. Our experience of Peregrine, limited to one chassis, is altogether insufficient yet to judge, but it is likely that this small engine with its numerous small impulses, and with M.E.P. falling away at low speed will give very little trouble with torque reaction periods at the speeds at which this phenomenon would be expected to occur. Moreover with an easy change silent third gear available the tendency would be to change down for maximum acceleration. We understand nevertheless that a torque reaction period has been experienced on the one Peregrine that we have, although its authenticity is a little doubtful. The other aspect of the matter is the benefit conferred by these dampers in steadying the front end of the chassis at high speeds. We already know that Peregrine, in its present condition, is very good from this point of view, as would be expected from the proportions of the chassis, and it is again questionable whether dampers are required, although these may be found of more benefit as the chassis ages, and becomes loose jointed. If experiment shows that these rigidly mounted dampers are not worth while, then we say it is of no use to have friction dampers on the front crossmember between the engine and the chassis. The dampers we have at present in this position do not seem to make any difference whether they are in action or not. | ||