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).
Alternative gearbox designs, focusing on the advantages of epicyclic units for achieving silent operation.
| Identifier | ExFiles\Box 15\5\ Scan053 | |
| Date | 7th November 1928 guessed | |
| contd :- -3- We have been over this ground so many times that none of it seems new to us, but I think the combination of the parts now suggested is novel, and gives some advantages not hitherto obtained. Amongst them is that there are no gears revolving when the car is standing, as is the case with most epicyclic gears, there is no drag on the gearbox gears because the controlling clutch makes everything as free as in the present car. The epicyclic unit is always considered to be a very silent form of gear, and therefore we are in hopes that the 3rd. speed will be almost as silent as the usual top speed. If it is not, it is possible to make the epicyclic unit single or double helical gears, which, if decently made, would ensure smooth running gears. In this arrangement we only have to deal with a quarter and a third of the engine torque in our clutch and brake (controlling the epicyclic unit), whereas Lanchesters, and most of the epicyclic people have to provide for one, two, and four times the engine torque with their brakes, hence they are difficult and unreliable. This second arrangement (though more difficult for us to design and make to the degree of perfection our reputation demands), is probably superior in silence and availability. It will be understood that the above arrangements are generally considered to be preferable to a very low top gear, and if a 3rd. speed is more easily obtainable than at present, we can use with advantage a somewhat higher top speed. In our second scheme although we consider the lubricating oil pressure quite reliable we are not stopped should it fail, as we still have a car nearly equivalent to the present - i.e. it would have 2 speeds and a reverse. In conclusion, I xxxxx shall be glad if you will pick out any patentable matter in these ideas so that we can secure them at an early date, as there is rather a rush with this type of thing at the moment, owing to the altered traffic conditions. Yours very sincerely, F.H. Royce - Sgd. | ||