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).
The incorrect use of ball bearings instead of roller bearings in the 'Condor' reduction gear.
| Identifier | ExFiles\Box 38\6\ Scan082 | |
| Date | 28th May 1919 | |
| To Da.{Bernard Day - Chassis Design} from EH. c. to Bn.{W.O. Bentley / Mr Barrington} FH1/LG28.5.19. X.3399 X.3383✓ RE "CONDOR" REDUCTION GEAR We have just noticed that the latest .55 reduction gear for the "Condor" engine has ball bearings each end of the planet pinions instead of roller bearings at one end as is our standard practice. We admit that at one time, when we were having a lot of trouble with roller bearings, it was thought that we might get better results by using ball bearings in place of rollers but our tests have proved definitely that the ball bearings in that position are very much worse than the roller bearings. We think the fact that ball bearings are instructed must be an over-sight as we pointed out to you that the "Condor" Gear should have roller bearings fitted with cages similar to the latest "Eagle" practice which has proved so successful. EH. R.R. 235A (500 D) (S.D. 408. 26-4-17.) Bm. 8/156/13. | ||