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).
Adjustments to the proportions of direct and servo-assisted braking.
| Identifier | WestWitteringFiles\M\2April1925-June1925\ Scan110 | |
| Date | 29th January 1929 | |
| [Handwritten] DA{Bernard Day - Chassis Design} AS INDIA 6.as.a.ENGLAND Braking Mr Royce does not want * / mechanics to be divided. combining OT [Typed] PROPORTIONS OF BRAKING. Y2540 Y2530 With further reference to H's memorandum of 26.II.28. Mr. Royce does not approve of the suggestion to reduce the direct braking and increase the power of the servo. He considers that the direct braking is very valuable, is appreciated chiefly when adjusting in difficult places, in which the full effort of the servo has, namely from forward to the full amount backwards, to be overcome. We estimate that with the enlarged dia. of cam shown on W.2008. with a 2° angle a net multiplication from the servo of approximately 8. will be obtained, which corresponds to a torque multiplication of approximately 25. In addition to this we increase the reduction from the brake shoe cam from 4. to 5. and the length of the metal lever on the test brake differs slightly, it will be found that this is practically the equivalent to a torque multiplication of .I. with the present system of levers and cams, and will give us what we believe we want. We find that the sheet metal lever requires to be reduced from S.826 as given on N.8005 of 2.180 approximately and that this length can be used on the front brake as this same lever will be to do both. We have looked into the question of altering the proportion of direct braking and find that quite a small alteration does not make much difference to the distribution of braking for servo efficiencies within the range we are likely to get. AD. | ||