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).
Notes on the design and performance of rotor, diffuser, piston, and bearing components.
| Identifier | ExFiles\Box 179b\3\ img036 | |
| Date | 14th January 1931 guessed | |
| -3- Cont'd.{John DeLooze - Company Secretary} Rotor. Dural - similar to ours but with curved dural inlet guide vanes in one piece with rotor. The vanes are bent over after machining. Plain bronze bearings for rotor. Spring drive of tangential springs. One gear train only not three like Kestrel. Wrapping clutch something like Hispano's - split ring with floating segments. (See sketch 2.) This bend gives a wrapping action - like a brake - in the driving direction and a freewheel in the overrun. With this type they have found at certain torsional speeds that the rotor drive actually creeps forward or faster than the mean speed of the driving member. They had no success with ball bearings for rotor - probably due to gear load. Rotor only statically balanced, by filing. Diffuser ring. Dural - side choke area - only 9 vanes as far as I remember. Large volute. Pistons. They state that this design was one of the chief factors in enabling them to get always high M.E.P. (193 lbs/sq.in.) of 'waffle' plate type and forged. (See sketch 3.) The waffle plate cells inside the head and the gudgeon pin bosses are all done by forging and is a remarkable piece of work. They say they could burn and score their pistons every time at 100 M.E.P. without the waffle plate cells in the head. The only internal machining is on the bore and all faces are faces for gudgeon pins. Pistons appeared very light. Good bedding. Previously they suffered from 'feathered' edge piston rings - similar I should imagine to which we have experienced. Big End Bearings. Elgit. Only about .020 thick. Steel shell less than 1/16" thick at slight warning in two halves. The end is split and bent out to form a tongue which fits in a slot to prevent rotation. (See sketch 4.) | ||