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).
Pump bearing failures, discussing corrosion, temperature, and gland leakage issues.
| Identifier | ExFiles\Box 131\5\ scan0146 | |
| Date | 7th July 1941 | |
| -2- metal surfaces were covered with an oil film when cooling down stationary through a temperature range between 160° C, and 85° C, in the presence of oxygen". It is probable that the pump bearings in the present series of tests were always running below 85° C. It is also fairly certain that the bearings in Rm{William Robotham - Chief Engineer}/ED{J. L. Edwards}'s tests were always running above 85° C. The conclusion to be drawn from this is that pump failure may be caused by corrosion as a result of temperatures in excess of 85° C. (Larger immersion heaters have been fitted to the rig. The switchgear which was ordered for these by the plant was of the wrong type. As a result, it will be three weeks before these are working. Another important difference between Rm{William Robotham - Chief Engineer}/ED{J. L. Edwards}'s test and ours is that of gland leakage. We have been almost free of this, Rm{William Robotham - Chief Engineer}/ED{J. L. Edwards}'s pump suffered from it. The original B.80 pump as tested by Rm{William Robotham - Chief Engineer}/Ed{J. L. Edwards} had a .25" drain hole which was very much masked by the bearing. There was no vent hole. In these circumstances, it is unlikely that the pump bearings could remain dry in the presence of serious gland leakage. It should be pointed out that improvements to the drainage of No.3 pump (above) are shown on PL.405. These have never been tried. The only sample of No.3 pump which has failed on the road so far, was assembled without one of the two Vellumoid washers. We think that the water drainage arrangements of any pump should be able to cope with any reasonable gland leakage. We consider that it is desirable to test pumps whose glands have been made to leak, on the rig. Rm{William Robotham - Chief Engineer}/GB. G.B. | ||