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).
Design and development of a supercharger drive for a Bentley.
| Identifier | ExFiles\Box 140\1\ scan0152 | |
| Date | 11th April 1935 | |
| To Sg.{Arthur F. Sidgreaves - MD} and Wer. from E.{Mr Elliott - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} E/SNR. E/BSN. Hs{Lord Ernest Hives - Chair}/Smth. Supercharger Drive - Bentley. Our experience with the supercharger drive on the Graham Paige shows us that the worm gear for the step up ratio, while giving a good initial result, is liable to become noisy in service. The rubbing speed is very high and wear develops; the slack thereby created is also liable to cause rattles at low speeds. For our scheme we decided to use spiral bevels as we believed it would enable us to get a silent drive more easily, and that it would remain silent. The bevels too are more efficient and the conditions of lubrication are not so onerous. A further advantage is that there is no offset required in arranging the drive and this enables the supercharger to be located closer to the engine, and avoids trouble with fouling the bonnet. Our initial scheming was directed towards arranging a double volute supercharger on the induction pipe driven from a spiral bevel box mounted on the crankcase with a tubular shaft driven by toothed couplings in between, the shaft being provided with a torsional spring device for taking up the slack. As a result of Lr{Mr Ellor}'s visit to U.S.A. we find the Americans have had some experience with the double volute blower and that it is not entirely satisfactory unless fed with a symmetrically distributed charge of mixture. As this condition is difficult to obtain with the ordinary single type of carburetter we are modifying our scheme to the single volute type. With regard to the arrangement of the installation, we have come to the conclusion that we shall have to make the drive in one unit with the blower itself, to avoid | ||