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).
The development and standardisation of a Tufnol guide bush for the High-Pressure S.U. Petrol Pump.
| Identifier | ExFiles\Box 149\3\ scan0041 | |
| Date | 11th March 1939 | |
| 1263 To By.{R.W. Bailey - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to By/SB.{Mr Bull/Mr Bannister} c. to Mx.{John H Maddocks - Chief Proving Officer} Rm{William Robotham - Chief Engineer}/JBD.{John B. Dixon - Fuel Systems}6/JH.11.3.39. Tufnol Guide Bush Fitted to the High Pressure S.U. Petrol Pump. The design of the S.U. petrol pump does not give positive location to the end of the spindle carrying the diaphragm and armature. This lack of control diminishes the clearance between the armature and the pot and also loads up the toggle mechanism working the contacts. To overcome this trouble, we have developed a tufnol guide bush which is fitted to the end of the armature and in which the spindle slides. A clearance of .009" is given to allow for the geometry of the toggle mechanism. On the endurance test rig we have completed a total of 7,300 hours on five units without experiencing any trouble from this bush and have definite evidence that the life of the pump is thereby increased. These bushes are fitted to S.B.V. and have completed 34,000 miles to date. They have been standardised for 'C' series Wraith a standardisation sheet has been issued for the Phantom III. We have also fitted these bushes to By's Bentley to obtain running on the low pressure pump, which on the rig has completed 1400 hours, with a view to having this modification applied to the 25/30 and Bentley II pumps now in service. To obtain the full benefit from this bush we have improved the inspectors rig and can now ensure that the end of the spindle is true with the armature to a .003 - .005" limit thereby reducing the possible side load. Rm{William Robotham - Chief Engineer}/J.B.Dixon. | ||