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).
Technical report comparing axle and differential components with Bentley and Packard models.
| Identifier | ExFiles\Box 127\1\ scan0253 | |
| Date | 20th November 1935 | |
| -11- Sft{Mr Swift}/Sctl/BH.20.11.35. Hypoid gears are fitted with an offset of 2.000 as against .650 on the Bentley Axle, this makes for maximum quietness, and if our axles were the same in this respect, our noisy gear troubles would be reduced. The pinion also is mounted without support at the nose and must allow considerable deflection at this point. Whether it has been found an advantage or not we cannot say. R.R. types of course, arepiloted here and are fully supported. The large Hypoid gear or crown wheel is of larger diameter than the Bentley, its diameter being 9.750 as against 8.500 on the Bentley. The face width alsoshows an increase over the Bentley ours having a width of 1.200 and the Packard 1.400. The differential consists of two pinions of substantial design, and only require one simple ground pin as compared with our expensive trunnion or star piece which employs two additional gears. The whole of the differential mechanism appears to be extremely simple in design yet robust looking, and only a few operations are required for it to be made ready for erection in the axle. Nothing could exceed the simplicity of the inspection cover, a plain steel pressing of dish like shape, it is easily removed, where upon the interior of the axle casing may be seen in all its fullness. An advantage that can be well appreciated. The Axle shafts are fastened, apparently directly to the driving wheels, this method being distinctly at variance with our more expensive way and making for cheapness. The method of axle attachment to the rear springs. Two block like pressings appear to be welded at each end of the tubular portion of the axle casing, over the top blocks go the bent round rods which serve for spring clips. The lower blocks form a pad which rests on the top plate of the spring. We would call attention to the difference between this method of fixing the axle and the R.R. Rear Axle with its spring clip forgings, packings and handwork required to give the fit and bedding demanded. | ||