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).
Interim report on a 100-hour bearing test to ascertain scoring under specific load and speed conditions.
| Identifier | ExFiles\Box 114\2\ scan0050 | |
| Date | 19th July 1934 | |
| INTERIM REPORT ON TEST NO. 61G.B. OBJECT OF TEST:- To ascertain whether any scoring of the rollers and tracks will occur under top gear loading conditions imposed by Messrs. Rolls Royce. BEARINGS:- N.1421. (Combined roller and ball bearing - full type roller) LOAD APPLIED:- 1420-lbs.Thrust. 1050-lbs. Journal. Later 100-lbs. Thrust, and 500-lbs. Journal. SPEED:- 4,500 R.P.M. DURATION OF TEST:- 100-hours. LUBRICATION:- Rust Veto. Pump feed. MAXIMUM TEMP. RISE:- Not taken. NORMAL TEMP. RISE:- " " ATMOSPHERIC TEMPERATURE:- " " GENERAL REMARKS RE TEST:- This bearing is a combined full type roller and duplex ball bearing having a split outer ball track, with the outer track, which takes thrust loads, ground undersize on the outside diameter. The bearing was tested for 26-hours under 1420-lbs. Thrust, and 1050-lbs. Journal load, at 4,500 R.P.M. and on examination preliminary signs of pending failure were noted on the ball tracks, heavy loading was also apparent on the roller tracks, and slight scoring had occurred on the roller tracks. The Thrust load was then reduced to 100-lbs, and the test continued for a further 49-hours (with an examination after 24-hours). A further scoring was noted on the roller tracks, but these appeared to be suffering rather severely from overload. The Journal load was therefore reduced to 500-lbs. After a further 25-hours (i.e. 100-hours total running) distinct signs of scoring were noticeable on the inner roller track and rollers. The outer roller track was somewhat pitted and appeared to be approaching a failure through overload, signs of scoring being also apparent. CONCLUSIONS DRAWN FROM TEST:- The scoring of the tracks and rollers which are typical of a full type roller bearing running at high speeds, was sufficiently developed during this short run to become obvious, and it was evident therefore that a bearing of this design is unsuitable for customer's requirements. Copies to:- W.M.C. G.M.C. Technical Office. Test Shop. | ||