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).
Issues with flywheel vibration in an engine and potential solutions.
| Identifier | ExFiles\Box 137\4\ scan0191 | |
| Date | 2nd March 1931 | |
| E.{Mr Elliott - Chief Engineer} HS.{Lord Ernest Hives - Chair} ) FROM R.{Sir Henry Royce} BY.{R.W. Bailey - Chief Engineer} ) (At Le CanadelHenry Royce's French residence.) C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} RG.{Mr Rowledge} C. to HY.{Tom Haldenby - Plant Engineer} RHC.{R. H. Coverley - Production Engineer} SECRET N634 R3/M3.2.31. JAPAN 3. ENGINE. X.634. X.5770. E's temporary double rear bearing is good for a trial, but I think now we have found that a flywheel vibration does take place at a certain speed we can certainly very definitely put up the speed by cutting out of the control the flexibility and disturbing effect of the crank. Heretofore we have been mystified by confusing this vibration with the torsional one, otherwise I am sure it would have been discovered earlier. I do not think that engine mounting or crankcase will have much effect, and the thing to do is to put up the speed out of reach i.e. above the master period, and if we cannot do so any other way we might make E's temporary fitting suitable for production if the assistance of the tail is not practical. If Mr. Grylls is right, and I think he is, then a stiff enough case is impossible, and counterweights, even small ones, are good by reducing the forces and increasing the mass. Therefore say .5 times the force acting on 1.2. times the mass might reduce the deflection to .4 - But it is possible that if we keep off the periods nothing more is needed and we have suggested that this may be possible by lightening the flywheel as on the 25HP., stiffening the back plate and the crankpins, then half balancing may help. I do not like thin web and long crankpins: we must get big ends to stand on narrow pins by nitro-hardening. R.{Sir Henry Royce} | ||