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).
Performance analysis of B.60 and B.80 oil pumps, with a comparative graph of delivery rates for different helical gear angles.
| Identifier | ExFiles\Box 149\2\ scan0218 | |
| Date | 13th May 1941 | |
| 1265 To Rm.{William Robotham - Chief Engineer} from Jnr.{Charles L. Jenner} c. to Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager} c. to Rm{William Robotham - Chief Engineer}/OES. Jnr.{Charles L. Jenner}7/SW.13.5.41. B.60 and B.80 Oil Pumps. We do not recollect that the B.60 pump has been bench tested for delivery, but as it is the same capacity as WRAITH, we can use the same curve adjusting it for 17° helical angle instead of 22°. [Graph Text] Y-Axis: PINTS. PER MIN. X-Axis: GINE RPM - 100 200 300 400 500 RPM Vertical Text Right of Graph: 5 TO 6 M.P.H. Graph line labels: 5° HELIX, ESTIMATED B60. 17° HELIX, WRAITH 22° HELIX. The delivery of any pump is not altered much when running fast whether it has helical or straight teeth, but at slow speeds say 275 RPM., we see a marked advantage in keeping the angle small because each delivery curve starts from a different origin. For instance 5° gears pump twice the amount of 17° which is the angle used on B.60 and B.80. Buick use 11° which is the angle I wanted to fit originally. The small delivery of B.60 and Wraith does indicate that we cannot afford anything in the way (continued) | ||