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 discussing the design and material specifications for a 9' register axle, referencing drawing no. 3008/4.
| Identifier | ExFiles\Box 7\3\ X 602 Axle Rear-page08 | |
| Date | 6th July 1936 | |
| RANSOME & MARLES BEARING Co., Ltd. -3- S. H.{Arthur M. Hanbury - Head Complaints} Grylls, Esq., D E R B Y. 6-7-36. considerable extent, so as to reduce weight to a minimum without affecting strength. DRAWING NO. 3008/4. This shews a 9" register axle, and is I believe one of the few which they have made for pleasure vehicles, it being noted that on these the minimum thickness is as low as 3/16", but from a talk I have had with them, this would be a little too thin for a job of your size, owing to the danger of excessive deflection. Incidentally, the casings are usually made from their K.F.12 Specification, which is a 1% to 1.1/2 % nickel steel, giving a maximum stress of 45/50 tons; yield point 30 tons minimum; elongation on 2" 22%; reduction of area 50%; Izod about 30 ft./lbs. Alternatively, they could be made in 3% nickel steel, but they do not recommend this as a general rule, owing to its tendency to temper brittleness, and the difficulty in stamping. I am confident that a talk with Mr. Cowell, their Chief Engineer, would be enlightening to yourself, while further owing to his very wide experience on rear axle work I am sure that a talk with him would be of very great utility. You will note that this construction of axle would give you equal results to your old axle, and would certainly eliminate the noise which you have encountered with the Scott. I have been having a glance at your drawing of the proposed new axle, and no doubt this design is based on your existing drawing, but from a casual glance I should anticipate that either excessive defects are likely to occur from the diff mounting. Incidentally, with respect to this you will remember that I mentioned the question of preloading the diff. bearing, and this, of course, is an arrangement to which you cannot adopt with | ||