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 failure of ball bearings used in place of roller bearings on an 'Eagle' Epicyclic Gear.
Identifier | ExFiles\Box 38\1\ Scan011 | |
Date | 24th October 1918 | |
R.{Sir Henry Royce} R.{Sir Henry Royce} 235a (500 T) (B.D. 408. 26-4-17.) Bm. 2/158/13. To R.{Sir Henry Royce} from EH. c. to CJ. c.to E.{Mr Elliott - Chief Engineer} c. to BY.{R.W. Bailey - Chief Engineer} c. to Ds. X.3383. EH1/LG.241018. BALL BEARINGS IN PLACE OF ROLLER BEARINGS ON "EAGLE" EPICYCLIC GEAR. After 32 hours running, we found half a ball in the epicyclic gear case. On taking it down to be examined we found that the ball had come from an Hess-Bright ball bearing which was fitted to the planet wheels. The Hoffman ball bearing, in place of the roller bearing on this same planet gear unit, was badly worn. The other two ball bearings which have run in place of the roller bearings appeared to be, from inspection and the amount of slack, in good condition. It may have been that the Hess-Bright ball bearing going increased the load on the one bearing which has failed, and so caused the wear, or it may be that this particular planet gear unit which these bearings were fitted to, was taking more than its share of the load. The outer race of the bearing which was worn in the same relative position as the roller bearings go. When we took the other two ball bearings to pieces, we found they were not in such good condition as we assumed by the feel. There are some very peculiar marks on the races and on some of the balls which appear as though they can only be caused by the balls skidding. Some of the balls are also pitted. The appearance of the bearings confirms that they are subjected to some very peculiar loads. We suggest that we might try a set of plain bearings not so much with the object of running Contd.) | ||