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).
Investigation into a foot brake countershaft bearing failure due to rusting caused by insufficient lubrication.
| Identifier | ExFiles\Box 84\2\ scan0116 | |
| Date | 8th March 1934 | |
| GWRY e Brake file v206 To Wer. from E/Lid.{A. J. Lidsey} E/Lid.{A. J. Lidsey}1/HP.8.3.34. c. Hs.{Lord Ernest Hives - Chair} Hx. re - B-25-AE - Rippon Demonstration (Wor{Arthur Wormald - General Works Manager}5/R.6.3.34). We have made enquiries with reference to the failure, due to rusting, of the foot brake countershaft bearing. It appears that two cases of this kind have previously occurred in the Experimental Department and that the cause of the corrosion at the bearing bush nearest the brake shoes is due to insufficient lubrication at this point. The lubrication of the two bearings which support this shaft is carried out by feeding oil from the Bijur centralised chassis lubrication system into one end of the shaft; the shaft is hollow and must be half filled with oil before the bearing furthest from the oil supply can obtain any lubricant. The system is exactly the same as on P.II and 20/25 HP cars, there is no reason therefore why the Bentley should be any worse than the other chassis if all three have equal treatment. When these brake countershafts are erected it is necessary to fill their hollow centres with oil before finally connecting up the lubrication pipes, if this is not done it is a very long time before the Bijur system will supply sufficient oil to fill up the hollow shaft and feed the bearing nearest the brake drum; this bearing in consequence becomes rusted up. Proof is available that this is the cause of the failure. Owing to lack of knowledge on this point quite a number of the first Bentley axles were erected without priming the shaft with oil and it is more than likely that B-25-AE is oneof them. Cars at present being turned out are correctly erected and steps were taken some little time back to ensure this. It is possible therefore that this may occur on the early Bentley cars, but not on thoseof recent production. E/Lid.{A. J. Lidsey} | ||