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).
Secret memorandum detailing modifications to a servo mechanism for improved performance and simpler construction.
| Identifier | Morton\M20.1\ img026 | |
| Date | 3rd May 1924 | |
| TO HS.{Lord Ernest Hives - Chair} [RV. EH. struck through] FROM R.{Sir Henry Royce} Copy to CJ. S E C R E T. R1/M3.5.24. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. 19910 [handwritten] SERVO. We send you herewith drawings of valuable modifications to the servo. You will see that we have altered the shape of the servo plates to make them very much lighter with a given degree of stiffness, and other parts are very much improved both in efficiency, simplicity and as manufacturing units. They demand less accuracy in erection and are less affected by wear in the long life that we have to consider. It has not yet been decided as to whether RRM. scheme shall have Des.60's second connecting rod as the final production, or whether it will be the modified Des.60 scheme in which the foot pressure goes to all the brakes. The parts as sent herewith have been carefully arranged for either type. As far as functioning is concerned you will see that there is considerably less bending on the central shaft and less load on the constantly running bearing of the servo. During some recent work Mr. Stent suggested that the servo driver plate should be made to float, and in considering the likely trouble with the link motion down to the compensator I decided that if we made this shaft to float we should overcome all trouble with these connecting rods in the course of time and also make the parts simpler and easier to erect. We hope you will like all the modifications and that you will be capable of fitting these to the 10,000 mile cars. If the foregoing is carried out we shall have the approved scheme in proportions chosen from the existing cars. These will be repeated on at least 3 cars with the improved details for the 10,000 miles trial, during which we expect you will be producing the parts for production, assuming that there will be no very serious modification needed because of the experience during the 10,000 miles trial. R.{Sir Henry Royce} | ||