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).
Different schemes and calculations for crankshaft balance weights.
| Identifier | WestWitteringFiles\V\March1931-September1931\ Scan038 | |
| Date | 13th March 1931 | |
| RG{Mr Rowledge}/TSN. E.{Mr Elliott - Chief Engineer}) FROM R.{Sir Henry Royce} BY.{R.W. Bailey - Chief Engineer} HS.{Lord Ernest Hives - Chair} ) (At Le CanadelHenry Royce's French residence.) Copy to SC. WOR.{Arthur Wormald - General Works Manager} RG{Mr Rowledge}/M13.3.31. X7 010. RECEIVED 1931 MAR CAR & AERO. W 1 CRANKSHAFT BALANCE WEIGHTS. I give below a confirmation of my telegram to Derby: "BALANCE WEIGHTS - TRESILIAN'S CALCULATIONS MOST "USEFUL AND I SUGGEST TAKE WITTERING TWELVE WEIGHTS "ALREADY MADE RETAIN ONE SIX SEVEN AND TWELVE DELETE "TWO FIVE EIGHT AND ELEVEN HALVE THREE FOUR NINE AND "TEN AND WE SHALL GET THE MOST EFFICIENT AND "PRACTICAL SCHEME WE SHALL FIND AND SUITABLE FOR "UNIVERSAL STANDARD SCRAP ALL OTHERS AND STOP PRODUC- "TION TO INTRODUCE THIS FIRST POSSIBLE MOMENT EVEN IF "ONLY THIRTY PERCENT - REPEAT WITTERING." Perhaps the conclusion is not quite correct, but was on the assumption that TSN's statement was true fact that we could not have the 4 weight scheme as we had decided. Since we are only able - because of the master period - to balance about 30/40% of the total out of balance it follows that we may be able to get all our balance weights in 4 pieces as far apart as possible, one on each web Nos. 1. 6. 7. and 12., and as they are exactly opposite one another we must have the most efficient scheme possible to counteract the couples. Mr. Elliott will probably tell us that Mr. Tresilian is mistaken in two points- i.e. that we cannot have this scheme, and if we could it can only be considered as an 8 weight job which brings the counterweights nearer together than originally intended. If however TSN. is right that 4 weights - viz: at 30° is impractical, or less efficient than his Sch. 111. then my modification of it seems to be the best possible, and it seems so enticingly orderly and practical, and appears to save the bearings more even than the 4 weight scheme, that you will all forgive my enthusiasm in my anxiety to get something going quickly. (it seems like shifting mountains sometimes to get something better to the buyer.) Mr. Elliott and I have always feared the want of rigidity of the crankchamber sideways more than vertically, and it will be realised that if we could counterbalance even 30% of the maximum - i.e. vertical- we might get the horizontal down to below half, which should make some very definite reduction in the deflection, and increase in the life of the bearings. Moreover it must help the steadiness of the flywheel and perhaps the thrashing of the con. rod sideways. (1) | ||