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).
Blueprint chart of gear reduction ratios for plain and compound planet gears.
| Identifier | ExFiles\Box 178\2\ img011 | |
| Date | 25th April 1940 guessed | |
| RATIO. LARGER PINION DIA: / ANNULUS DIA: COMPOUND PLANET PLAIN GEAR PINION RATIO FOR COMPOUND PINION = LARGER PINION DIA: / SMALLER PINION DIA REDUCTION RATIO DESIRABLE REDUCTION RANGE PINION RATIO 1 1/2 SUN DRIVING PINION RATIO 2 SUN DRIVING PINION RATIO 2 1/2 SUN DRIVING PLAIN GEAR SUN DRIVING PINION RATIO 1 1/2 ANNULUS DRIVING PINION RATIO 2 ANNULUS DRIVING PINION RATIO 2 1/2 ANNULUS DRIVING PLAIN GEAR ANNULUS DRIVING SMALLEST PINION APPROX LARGEST PINION | ||