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 to a supplier discussing bearing design modifications, dimensions, and capacity.
| Identifier | ExFiles\Box 84\4\ scan0333 | |
| Date | 3rd November 1937 | |
| c. Dev c. Rm.{William Robotham - Chief Engineer} GRY{Shadwell Grylls} 202, FJH{Fred J. Hardy - Chief Dev. Engineer} Da{Bernard Day - Chassis Design}/Hdy.{William Hardy}25/G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 3rd. November 1937. The Hoffmann Manufacturing Co. Ltd., Chelmsford. For the attention of Mr. C.H. Smith. Dear Sirs, We thank you for your letter of the 30th October (ref. CHS/AMB.102251) and for the print of your drawing No.41-477, Section 74, enclosed therein. We think that the bearing as now designed will suit us very well, and we agree that the width should not be further increased to obtain more perfect self alignment of the thrust races. From the point of view of the rigidity of our pinion, we should prefer as large a bore in the bearing inner race as can be allowed without detriment to the bearing, and we shall be glad if you will kindly say whether this may be made 1-3125" instead of 30 m/m.{Mr Moon / Mr Moore} The increased distance of the radial load carrying part of the three row bearing from the pinion compared with our standard bearing throws more load on to the nose bearing and in consequence we should like to increase the capacity of this bearing. There is no room for an increase of outside diameter, but the width may be increased by about 50%. The standard bearing is a roller 17 x 47 x 14 and the top gear load with the proposed three row bearing in use is 1,430 lbs. This will become 3,600 lbs. in bottom gear. Is it practicable to use the next larger size of roller (5/16") without an increase of the outside diameter of the bearing with any advantage, and if so what percentage increase of capacity can be obtained ? The inner race is formed integral with the bevel pinion, but could be reduced in diameter by .062 as required to accommodate half the increased roller size. The outer race is the double lipped type. There is also the possibility of increased width of roller without increase of diameter. We have room to accommodate two .250 rollers side by side in a single groove in the outer race. Have you any objection to a bearing of | ||