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).
Letter to Vandervell Products regarding issues with rocker bushes and the failure of experimental three-layer big end bearings.
| Identifier | ExFiles\Box 115\2\ scan0479 | |
| Date | 24th June 1939 | |
| 1020 Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}5/MH.{M. Huckerby} 24th. June, 1939. Messrs. Vandervell Products Ltd., Western Avenue, Park Royal, LONDON, W.3. Dear Sirs, We have had the following request from Production in respect of the Vandervell rocker bushes EB.4309. As copied from your original drawing B.2204, the bore of the bush when pressed in position is .595 dia. which has to be opened out to a final diameter of .625. This is carried out by means of broaching not reaming, and in consequence there is some difficulty in broaching out this amount. They would like to receive bushes which have a bore, say, of .615 dia. when pressed in position, leaving only .010 to broach out to final size. We would like your recommendations on this, in the meantime they are reaming out and then broaching, which is, of course, unnecessarily expensive, there being two operations where one should do the job. Experimentally, we have some disappointing news in that one of the three layer big end bearings which we have for trial, has failed after 1 hour's endurance under our normal conditions. Prior to the endurance the unit had run 11 hours full throttle on power curves etc. but this running is negligible in comparison with endurance conditions. As you are no doubt aware, we ran 3 big ends in your normal Babbit and 3 in the 3-layer material, the Babbit and the remainder of the 3-layer bearings being in good condition. The condition of the failed 3-layer bearing is that all the surface coating has gone. A new replacement 3-layer bearing has been fitted and after dismantling and thoroughly cleaning, is being prepared for further endurance. | ||