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).
Features and advantages of a double-entry blower supercharger compared to a single-sided rotor.
| Identifier | ExFiles\Box 179b\1\ img342 | |
| Date | 28th March 1933 | |
| SG.{Arthur F. Sidgreaves - MD} FROM R.{Sir Henry Royce} ORIGINAL R2/W28.3.33. Sent off 4.4.33. C. to WDR. HG. HS.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} T. E.{Mr Elliott - Chief Engineer} LR.{Mr Ellor} SUPERCHARGERS. X4850. I fear Derby have not yet realised the features I am aiming at with the double entry blower. (1) The first thing is its mechanical strength against centrifugal action and backfires, and (2) the rotor should be compared with a single sided rotor of the same dia. The disadvantage set against it, which may be very little - of the extra dia. of the volute - has advantages of being less liable to burst through backfires, and more efficient, as the air does not have to be turned over, but is delivered into the wind stream in a more orthodox way. I am fully aware that multiple stage blowers or centrifugal pumps have to be single sided, and it is very difficult to build them otherwise. It will be noticed that it depends somewhat upon the volume that you are expecting the blower to deliver. If a large volume, the double eye is undoubtedly an advantage due to the smaller eye and the more economical entrance to the air. As we are talking about blowers of increased capacity the double eye looks as though it would certainly be the better. I imagine two double carburetters of horizontal pattern, and the air intakes going right across or coming towards one another, and rising up into the position that we had for LR{Mr Ellor}'s Schneider intake. R.{Sir Henry Royce} | ||