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 detailing issues and proposed modifications for an oil pump drive system, referencing specific part numbers.
| Identifier | ExFiles\Box 77\1\ scan0156 | |
| Date | 25th May 1929 | |
| H/ X3672 POST RECEIVED 7 JUN 1929 OY-5 May 25th, 1929. Mr. R.W. B. Bailey, Rolls Royce Ltd., Derby, England. c - Mr. E.{Mr Elliott - Chief Engineer} W. Hives Dear Mr. Bailey: OIL PUMP DRIVE - SECTION 5171 We have already written to you in connection with Proposed Chassis Alteration No. 2 on Oil Pump Drive, that we thought the square tube drive using the same tube as the Silver Ghost had advantages in safety. And we sent you a print, A-13240, therewith, showing how we proposed to make the drive. I now enclose a further print A-13240, marked up in pencil to illustrate what we find wrong with the drive as originally laid out. (1) By deliberately feeding piston stop pins, washers, and finally a 2BA nut into the suction pipe of an oil pump we finally succeeded in stopping the pump (with remarkable absence of damage to the teeth) and on dismantling found that the top of the boss on the bronze wormwheel had opened out at each serration, allowing the wheel to turn on the spindle. There was no sign of damage to the square tube or other parts of the drive. This gear E-76728 is somewhat weaker at the boss than its predecessor E-7077 on the C.I. head engine, which doubtless accounts for the fact that on earlier cars the whole of the drive and the end of the oil pump spindle were twisted and wrecked when the pump jammed and finally the teeth sheared off the bronze wormwheel. (2) It is desirable to open up the lower end of the bore in the crankcase bottom half so that the square tube will pass through it. This is going to be particularly necessary when we strengthen the wormwheel sufficiently to make the sq. tube act as the breaking piece. It is very desirable to do this on our L.H. jobs -continued- | ||