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).
Test report on the 50-hour endurance run of a 'Tufnol' gear for a Wraith oil pump.
| Identifier | ExFiles\Box 149\2\ scan0194 | |
| Date | 14th April 1939 | |
| 1265 To RHC.{R. H. Coverley - Production Engineer} from HPS{Horace Percy Smith - Experimental Factory Mgr}/Bl. [crossed out] c. to Rm.{William Robotham - Chief Engineer} c. to Ba. [crossed out] c. to RHC{R. H. Coverley - Production Engineer}/DWB.{D. W. Brown} [crossed out] HPS{Horace Percy Smith - Experimental Factory Mgr}/Bl.1/CB.14.4.39. WRAITH OIL PUMP. "Tufnol" Gear. Test I - 50 Hours Endurance. With an EW.965 type gear produced in "Tufnol", fitted into a standard EW.973 LOP. oil pump, it was found that at 70°C oil temperature, the pump tightened up, although the initial end clearance was .0043". An independent check was taken of the "Tufnol" gear, which showed that its longitudinal expansion at 70°C was approximately .0055". After reducing its length by .0035", it was retested in the pump and proving satisfactory up to 80°C, a delivery check was taken, and a 50 hours endurance run completed at 2,000 P.R.P.M., 25 lbs./sq. in. delivery pressure, with the oil temperature maintained at 75°C maximum, using Motorine "C" oil. At the conclusion of the run, a delivery check and also hot and cold priming tests were taken. The deliveries before and after test are shown in BL.2327, being roughly 100 pts./hr lower at the end of the runs. In spite of the large end clearance, the priming qualities both cold and hot were satisfactory. Tested in comparison with a standard gear, this "Tufnol" gear was slightly quieter but not ideally so. When stripped and examined after test, the general condition of the "Tufnol" gear was reasonably good. There was evidence of thrust on one face and "scruffing" on the periphery of the gear. Dimensionally, the wear was .0044" on the length and .0015" diametrically, whilst the wear on the A/C casing registered .001" on the depth and .0005" diametrically. continued. | ||