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).
Modification to the Bijur pump design to prevent oil leaks.
| Identifier | ExFiles\Box 27\1\ Scan242 | |
| Date | 6th June 1929 | |
| X3806 DA.{Bernard Day - Chassis Design} from Hs{Lord Ernest Hives - Chair}/Gy. c. to BY.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Gy1/LG23. 6. 29. DESIGN OF BIJUR PUMP TO N.SCH. 2330. Recently we have had more trouble with regard to oil leaks down the dashboard from the Bijur Pump, when it is filled right full. Since a great many of these pumps have been made, we have taken steps to fit an adaptor together with a leather washer which has been proved to cure it. Nevertheless, the difficulty would appear to be due fundamentally to the design of the cover on the Bijur pump as the filler cap allows an oil level higher than the main body of the tank and higher than the bottom of the slot in which the pedal is fixed. Hence, the oil on finding its level, is bound to escape through the working clearance of the plunger and the filter top. Before discovering this, we believed that the leather washer fixed between the facing of the cover and the filter top would be sufficient to cure the trouble but in spite of this a large number of pumps were shewn to leak. The principle of the adaptor which we have fitted in place of the filling plug is that while the oil is being poured in, air is trapped immediately the oil reaches the bottom of this adaptor, and the adaptor itself fills up before the remaining part of the container. In other words the oil level is reduced thereby allowing expansion to take place without ill effect. The old filler cap shewn on N.sch.2746 fits inside the adaptor. You will realise that this procedure can only be regarded as provisional and that we should appreciate some alteration in the design of the cover to enable oil to be added conveniently and yet at the same time the pump to be free from leaks. Enclosed please find print of Adaptor. Hs{Lord Ernest Hives - Chair}/F.Gaye. | ||