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).
Manufacturing progress and challenges of Bentley composite brake drums.
| Identifier | ExFiles\Box 84\2\ scan0372 | |
| Date | 30th December 1935 | |
| To RHC.{R. H. Coverley - Production Engineer} xob Hs{Lord Ernest Hives - Chair}/AFM.{Anthony F. Martindale}18/KN.{D. G. McKechnie - Sales}30.12.35. Bentley Composite Brake Drums. We have noted the progress of these drums in the shop, and from the work already done we have learnt the following - (1) That these drums should be so designed that machining operations on the austenitic liners are as simple as possible. (2) That forged N.M.C. liners in the condition received distort during machining. The riveting shown on Hs.{Lord Ernest Hives - Chair}2205 was found to be impractical, and dowel ended screws had to be substituted. The method of fixing liners shown on Rm.{William Robotham - Chief Engineer}36 is more simple still and we would like the remaining 3 drums made in this manner. To complete the first pair of drums we now need the cast N.M.C. liners already ordered, as one forged liner was scrapped due to distortions. If these cast liners also distort, we would like to try removing internal stresses by heat treatment; first by holding one at 650° C. for 30 mins., and if this is inadequate, then 950°C. for 30 mins. We have yet to learn what complications will arise when brinal liners are used, but we will continue to co-operate with the shop. Hs{Lord Ernest Hives - Chair}/A.F.Martindale. | ||