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).
The mounting and drive for a Bensport blower on the crankcase.
| Identifier | ExFiles\Box 140\1\ scan0018 | |
| Date | 24th August 1932 | |
| To R.{Sir Henry Royce} from H.{Arthur M. Hanbury - Head Complaints} c. Sg.{Arthur F. Sidgreaves - MD} Wer. Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} X 209. E.9/HP.24.8.32. re Bensport blower, mounting and drive. Please find herewith a print of LeC.3167 showing the proposed mounting and drive for the blower on the crankcase. For simplicity and saving of space we have made the rear end cover of the blower and the flange mounting bolted to the engine in one piece. This also assures the concentricity of the blower spigot and bearing housing. Any eccentricity of the crankshaft with the crankcase spigot is to be taken care of by float in the coupling. We have not attempted to use the mass of the moving parts of the blower to damp the crankshaft as we think it presents too many practical difficulties. It is likely, however, that some benefit will accrue from the presence of the blower. We find for example that on our experimental bench set-up where the blower is coupled to the engine by a thin shaft of a pre-arranged degree of flexibility, that the half speed vibration of the crank is split up into two periods of less intensity. The drive with the spring coupling should retain this characteristic, and should be even better for the presence of a certain amount of damping in the coupling itself. A normal slipper wheel of the Silver Ghost type is mounted in conjunction with the coupling on the end of the crankshaft, and should be capable of dealing with any periods which arise. The design shows the largest mass that can be got in, but we shall expect to reduce this experimentally as we are using substantially less inertia on Peregrine at the moment. The coupling we have altered to the | ||