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 efficiency and coupling of a Roots type blower compared to a Powerplus system.
| Identifier | ExFiles\Box 3\4\ 04-page032 | |
| Date | 11th May 1932 | |
| - 3 - E.1/HW.11.5.32. ---------- (3) Higher overall efficiency. (4) Begins to operate at a lower speed than the Roots due to smaller leakage factor. (5) It is not necessary to have a by-pass passage shunting the blower for slow running. In coupling up the Roots type blower on the Bensport to the front end of the crankshaft we have shown the blower shaft hollow with a flexible driving shaft passing through it. This scheme is not possible on the Powerplus due to the vanes intersecting the shaft, and we shall have to use a spring coupling for this purpose. With regard to the starting handle it was said that the blower shaft would be sufficiently stiff for the purpose of turning the engine. K.{Mr Kilner} | ||