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).
Coolant pump rig tests to investigate and reproduce bearing failures.
| Identifier | ExFiles\Box 131\5\ scan0145 | |
| Date | 7th July 1941 | |
| To: Rm.{William Robotham - Chief Engineer} from Rm{William Robotham - Chief Engineer}/GB. c. Jnr.{Charles L. Jenner} Rm{William Robotham - Chief Engineer}/Col. Rm{William Robotham - Chief Engineer}/GB.1/RH.{R. Hollingworth}7.7.41. 1114 Coolant Pump Rig Tests. The object of these tests was to reproduce the bearing failures which have occurred on the road and to carry on development work. It was thought that a possible cause of bearing failure was fatigue due to the loads imposed by the fan. Accordingly, all pumps have been run with fans. The rig consists essentially of a stand which carries a water tank with an immersion heater. The pump is bolted to the stand and is driven by belt from a 25 HP. variable speed motor. So far, the following pumps have been run. A pump speed of 4250 r.p.m. is maintained. No.1. Pump to EB.4208 with unventilated S.K.F. double row sealed bearing. This is the original B.80 pump with bakelite gland located in pump case. 29 1/2 hours. No.2. As No.1. except bearing ventilated. 100 hours. No.3. Pump to RE.935. This pump has two separate Hoffman bearings (117 F.S) and a Morgan Stuart carbon gland which rotates with the shaft. 100 hours. None of the bearings in any of the above pumps feel any the worse as a result of the tests to which it has been subjected. No.1. is the same as that on which Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards} experienced bearing trouble after only 6 1/2 hours. One essential difference between Rm{William Robotham - Chief Engineer}/Ed{J. L. Edwards}'s test and the present series is water temperature. Rm{William Robotham - Chief Engineer}/ED.{J. L. Edwards} used a water temperature of 80-90° C. Our water temperature was approximately 60° C, because of the low power of the only heater available at the time the tests started. In "Experiments on the Corrosive Wear of Lubricated Surfaces" by Wing Commander W. Helmore, the following occurs "Corrosive wear was found to be at its maximum where the -Continued- | ||