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).
Use of metallic versus non-metallic bushes for contact breakers in Bentley and RR battery ignition systems.
| Identifier | ExFiles\Box 163\7\ img234 | |
| Date | 1st January 1934 | |
| WST 86120. To W.O.R. from E.{Mr Elliott - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} Mx{John H Maddocks - Chief Proving Officer} Hs{Lord Ernest Hives - Chair}/Wst. By/ND. E.3/HP.1.1.34. re Bentley and RR. Battery Ignition. Referring to Sg.{Arthur F. Sidgreaves - MD}18/E.18.12.33 in connection with the material for the contact breaker bushes, I would personally rather use metallic than non metallic substances for all functions where extreme reliability is required unless the conditions were unfavourable as they will be in this case unless the bearing is occasionally lubricated by hand as requested in our instruction book. A bronze bush will not operate satisfactorily if run dry and although the present RR. lever is generally giving satisfaction we have reports of trouble of a sufficient nature to warrant some modification. It would however at the present juncture be manifestly unwise to modify the RR. practice until we have had more experience with the Bentley. My own experience of bakelite bushes is that I have used a Delco double breaker set so fitted for four and a half years without failure and without once doing anything to lubricate these bearings. We have a metal bush we propose to try out known as the Oilite bush made of spongy bronze which retains practically permanently in its structure a percentage of non-drying lubricant, but this is experimental at present. We used an Oilite bush on the front end of the engine suspension of the Bentley on the last test in France to avoid fitting a grease gun connection as on the 20/25 and it apparently fulfils the purpose. With regard to the 40/50 and 20/25 contact fingers, the position therefore remains that standardization sheets X.6118 in respect to contact finger DB.{Donald Bastow - Suspensions}346 will remain in abeyance for the time being. E.{Mr Elliott - Chief Engineer} | ||