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).
On the satisfactory performance and new hardness standardisation for engine timing gears after a 16,000-mile test.
| Identifier | ExFiles\Box 136\1\ scan0208 | |
| Date | 27th May 1937 | |
| 115/5' To RHC.{R. H. Coverley - Production Engineer} from HPS.{Horace Percy Smith - Experimental Factory Mgr} c. to Rm.{William Robotham - Chief Engineer} HPS{Horace Percy Smith - Experimental Factory Mgr}/3/VS.{J. Vickers}27.5.37. ENGINE TIMING GEARS. Referring to the attached memo RHC{R. H. Coverley - Production Engineer}/AEC.2/LS.21.5.37. The toughened dynamo pinion and idler gear in S/ZNX material fitted in B.4 unit have now been examined after 16,000 miles in chassis 6.B.IV., and are in a very satisfactory condition. The idler gear and dynamo pinion were heat treated to obtain Brinell figures of 398 and 330 respectively, and were gear-cut in the heat treated condition. No increase in backlash has taken place during the course of this test, and the Brinell hardness has remained consistent, in view of which Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} is issuing a standardisation sheet for these two gears to be produced in S/ZNX. heat treated to within a hardness range of 364 to 387 Brinell. HPS.{Horace Percy Smith - Experimental Factory Mgr} [Signature] | ||