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).
Manufacturing difficulties and failure analysis related to a jaw, spindle, and bearing assembly.
| Identifier | ExFiles\Box 95\1\ scan0456 | |
| Date | 25th November 1937 guessed | |
| -2- Also difficulty exists in maintaining this accuracy as the hand facing cutter for the jaw faces locates from the core size of the serrated bore, which is not necessarily true with the serrations. The edges of the jaw have to be locally softened to enable this hand cutter facing to be done, as all edges of copper plated forgings are prone to this trouble. (copper plating to prevent attack of carbon). We found a possible .002 slack to exist on the drawings between the serrated bores of the jaw and the serrated spindle. (Now corrected). Further we cannot produce serrated spindles to fit broached holes without limits and at the same time be free from slight slack. It is almost impossible to guarantee the alignment of the washers and occasionally the serrated spindle is driven through, cutting grooves in the washer. Extreme accuracy is required in producing the roller bearing tracks true with the serrated bore of the bearing. The roller must also be produced practically without limits, otherwise the poundage is effected. Any errors in parallelism of even .0005 in the jaw or bearing assembly will effect the bedding of the rollers which may result in increased load on one end of the rollers. This in turn may cause failure of a roller and its collapse would very quickly bring about the failure of the remaining rollers. One is led to believe that this has been responsible for the failure of the Steering returned from Paris, Chassis 3.BO.94. judging by the condition of the rollers in one side of the bearing. We agree that chips have been removed by driving the spindle through a misaligned washer, but do not consider these chips to be the cause of breakage as it is impossible for chips to get into the roller track. The reason for this is that all contact surfaces of inner races, distance piece and washers are so tightly in contact that chips could not find a way into the bearing. They are just pushed through the Distance piece and fall outside the serrated side of the Rocking Shaft Jaw. -2- | ||