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).
Results of comparative thrust bearing tests, including wear and failure analysis.
| Identifier | ExFiles\Box 102\4\ scan0006 | |
| Date | 13th October 1925 guessed | |
| -2- 3rd Test-contd- This represents 1st Speed conditions. On examination the bearing was found to be quite good but the end float was .0015. 4th Test was run off 525 r.p.m. with 5,800 lbs load for 10 hours. 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.III (16,000 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 | Speed of Rig. | Effective Load | Time Run | Remarks. 1 | 12 | 5/16 | Direct Drive | 2000 r.p.m | 1,000 lbs | 20 hrs. | All Balls badly scored 2 chipped. 2 | 12 | 5/16 | Second Spd | 1220 r.p.m | 2,500 lbs | 10 hrs. | Balls scored 1 chipped badly, also Races scored NEW DEPARTURE NO.207. 3 | 14 | 5/16 | Second Spd | 1220 r.p.m | 2,500 lbs | 10 hrs. | 3 balls badly chipped. NEW DEPARTURE NO.306. 4 | 9 | 7/16 | Direct Drive | 2,000 r.p.m | 1,000 lbs | 20 hrs. | Float increased .001 5 | 9 | 7/16 | Second Spd | 1.220 r.p.m | 2,500 lbs | 10 hrs. | Float .001. 6) 7) | 9 | 7/16 | First Spd Reverse | 700 r.{Sir Henry Royce} 525 " | 4.300 5.800 | 10hrs 10hrs | Float .0015 .003. RHC.{R. H. Coverley - Production Engineer} | ||