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).
Letter to Major B.C. Carter of the Royal Aircraft Establishment regarding crankshaft torsional vibrations and bearing stiffness formulas.
| Identifier | ExFiles\Box 25\3\ Scan342 | |
| Date | 1st May 1928 | |
| X634 Expl: Dept: HS{Lord Ernest Hives - Chair}/TML/LG. 1st. May 1928. Major B.C. Carter, Royal Aircraft Est., St.{Capt. P. R. Strong} Farnborough, Hants. X 6010 Dear Sir, CRANKSHAFT TORSIONAL VIBRATIONS. We have received your letter dated 30.4.28. and ref. 70/D/6f/30, together with the attached frequency figures completed. We shall comment on these results shortly when we have had time to compare them with our own work. On the 31st. ult. Mr. Tresilian visited Mr. Constant at Cambridge and had a long and interesting discussion on Crankshaft problems. We note that he is principally engaged in developing a 'rational' formula for the out-of-bearing stiffness, and then hopes to find the necessary relation between the in-bearing and out-of-bearing values. We ourselves have obtained very satisfactory results with your formula on all the shafts we have tested, but Mr. Constant attributes this either to luck or to the fact that we usually deal with shafts that have a fairly close resemblance to each other. We would suggest that his mistrust is based on the fact that your formula is entirely empirical, and therefore may be found only to hold over a certain range of shafts. In accordance with Mr. Constant's request we give below some figures for measured out-of-bearing stiffness which we do not think you have yet seen. They are for single cranks. contd :- | ||