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).
Examination of a new front axle, highlighting design flaws and recommending improvements.
Identifier | ExFiles\Box 18\1\ Scan004 | |
Date | 10th June 1926 | |
To Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} X7840 R12/M10.6.26. RE. NEW FRONT AXLE FOR EAC. 8. X.7420 X.7840 X.8420 The parts of this axle were examined and I was sorry to see that we had not realised the importance of not having square corners. We must very carefully round the radius of all the corners. The worst point was the front pivots which were like the Derby drawings, which were also wrong, and not like the WW. drawing. DA.{Bernard Day - Chassis Design} will give the necessary instructions. Also some of the boring out is not very wise as it may be carried too far and leave a weak place. This particular lightening feature should be deleted. Regarding the axle forging it is to be regretted that the shaft was not a little lower. At the same time the whole window cut with the lever is larger (and with square corners) than intended. It clears the boss by a good deal more than was shewn on the original drawing, and the radii in the corner of the window have been lost. It will be seen that we can increase this if we could bring the shaft a little further down, by altering the die; it would be well worth the slight extra weight. We could also reinforce the top flange opposite the window. DA.{Bernard Day - Chassis Design} supplies a drawing. I think this axle is vastly superior to the old one. It is lightened as much as seems safe and we hope it will stand up on the bumping rig, which it should be subjected to at the first possible minute. It would appear that the machining is much more practical and the lubrication much more perfect and lasting than in the older design, in addition that it saves about 25% of weight on the parts affected, making a total of 46 lbs. on the lightened specimen, and nearly 70 lbs. on the original front wheel brake axle, which was heavier than our drawings shew. For elegance, and to save the weight of the parts stressing themselves and the fixing, I have recommended that the steering arm levers should be lightened towards their outer ends principally by filing off the corners and making them nearer to circular, which should not very much alter their resistance to torsion, but considerably add to their appearance. R.{Sir Henry Royce} | ||