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).
Balancing a Bentley crankshaft, based on methods from Packard and outlining required experiments and modifications.
| Identifier | ExFiles\Box 85\5\ scan0108 | |
| Date | 10th March 1936 | |
| To RHC.{R. H. Coverley - Production Engineer} x 217 Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}3/KW.10.3.36. Bentley Crankshaft. While I was in America the Packard people explained to us that we could balance the 7 bearing crankshaft with less inertia than in our present arrangement by using 4 balance weights only. We have carried out tests in which each crank pin was loaded as for the centrifugal forces, and found the resulting deflection could be counteracted by a single force in the centre of the crankshaft. The equivalent to this to give static balance is 4 balance weights set at the unusual angle shown on Rm.{William Robotham - Chief Engineer}89. Will you please put in hand the necessary balance weights for experiments, the thin ones to balance only the centrifugal masses, and the thicker ones to balance also half the reciprocating weight. We have left it to you exactly how the second nut to hold each balance weight is fitted, but we should like the spot facing to accommodate the nut to be as small as possible, even if this means making a special spanner. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} | ||