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).
Letter from Ransome & Marles Bearing Co. Ltd. detailing the load capacities for several special MDJT bearings.
| Identifier | ExFiles\Box 84\4\ scan0371 | |
| Date | 29th December 1937 | |
| -2- 29.12.37. Special MDJT.30. 11 - 9/16" balls/row Contact angle 35° 2000 1610 1780 3000 1400 1540 Special MDJT.30. 11 - 17/32" balls/row Contact angle 35° 2000 1600 3000 1274 1400 (Kindly note that the capacities for the Special MDJT.30 with 11 - 9/16" balls are as above and not as stated in our letter of the 5/10/37.) For the SpectreCodename for Phantom III. Speed. Capacities lbs. Journal. Thrust. 2/MDJT.35 12 - 9/16" balls/row Contact angle 35° 2000 1760 1940 3000 1540 1700 4500 1345 1480 3/MDJT.35. supersedes above and has ground slots in the face of one outer. 12 - 9/16" balls/row Contact angle 35° 2500 1640 1800 Special MDJT.35. 11 - 19/32" balls/row Contact angle 35° 2500 1650 1815 The special bearings are ones suggested by R.{Sir Henry Royce}& M.{Mr Moon / Mr Moore} Theoretically the pure thrust capacity can be taken as OC sin ø but in practice owing mainly to the increased fatigue when running under a pure thrust, bearings will not stand up to a thrust rating based on the above. The thrust capacities for a bearing with ø = 35° = Journal capacity + 10%. For a bearing having 12 - ½" balls/row & ø = 45°. The capacities are: Speed. Thrust. (lbs.) 2000 1820 3000 1580. Yours faithfully, RANSOME & MARLES BEARING CO.LTD. (signed) C.G.H. Richardson DIRECTOR & GENERAL MANAGER. | ||