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).
Various thrust bearing tests.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan55 | |
| Date | 12th June 1925 | |
| R.R. 493a (50 H) (D.D. 31, 12-6-25) J.H.D. EXPERIMENTAL REPORT. -2- Expl. No. REF: After the above tests the bearing was found to be in good condition but the float had increased to .003. This figure represents actual wear in the bearing. These tests prove this bearing to be far superior to the others and a bearing of this type was fitted to the rear axle on chassis 9-G-111 (10,000 miles). Below we give the figures for the various tests :- STANDARD TYPE OF THRUST. Test No. | No. of balls in each row. | Dia! of balls. | Conditions. | ~~Revs.~~ Speed of rig. | Effective load. | Time run. | Remarks. 1 | 12 | 5/16 | Direct drive. | 2000 | 1000 lbs. | 20 hrs. | All balls badly scored. 2 chipped. 2 | 12 | 5/16 | 2nd. speed | 1220 | 2500 lbs. | 10 hrs. | Balls scored 1 chipped badly, also races scored. NEW DEPARTURE. 3 | 14 | 5/16 | 2nd. speed | 1220 | 2500 lbs. | 10 hrs. | 3 balls badly chipped. NEW DEPARTURE NO. 306. 4 | 9 | 7/16 | Direct Drive. | 2000 | 1000 lbs. | 20 hrs. | Float increased .001 5 | 9 | 7/16 | 2nd. speed | 1220 | 2500 lbs. | 10 hrs. | Float .001. 6 7 | 9 | 7/16 | 1st. speed. Reverse. | 700 525 | 4300 5800 | 10 10 | Float .0015. .003. RHC.{R. H. Coverley - Production Engineer} | ||