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).
Material experiments for the Goshawk II rear axle shafts due to wear on the gear teeth.
| Identifier | ExFiles\Box 49\2\ Scan084 | |
| Date | 18th May 1922 | |
| R.R. 199 (250T) (SD696 19-7-17) MP 180865 X4256 BY10/H.{Arthur M. Hanbury - Head Complaints} 18. 5. 22. SJ. for R.{Sir Henry Royce} c. Hs.{Lord Ernest Hives - Chair} GOSHAWK II. REAR AXLE SHAFTS. Owing to the wear on the gear teeth of the wheel which is formed integral with the shaft, it has been necessary to reconsider materials. The experiments we are trying are:- 1. Nickel Chrome Pinion of a similar hardness to the shaft which is also nickel chrome. 2. Nickel Chrome Pinion slightly softer than the shaft. 3. A change of material on the shaft from Nickel Chrome Steel to Case Hardened Air Hardening Steel. The material of the original pinion was C.H.N.S. There is one other proposal, namely, to make the axle shaft in C.H.N.S. The reason why I did not adopt this was that such varying results are obtained, according to the hardness number of the C.H.N.S. used, but by selecting casts it would be possible to obtain C.H.N.S. suitable for this duty. In order to make my point clear, I am giving you below average figures taken from (a). Nickel Chrome Steel Axle Shafts for the 40/50. (b). C.H.N.S. Propellor Shafts where the hardness number is kept up and special casts are selected to produce the forgings from. (c). C.H.N.S. as used for Camshaft Bars from which you will note that whilst selected C.H.N.S. is practically as good as ordinary Nickel Chrome Steel from a technical point of view as well as from the ultimate strength, the soft C.H.N.S. gives a low ultimate and a lower Stanton. Brinell. Stanton. Ult. Yield. Elongtn.%. R.A%. (a). 285-302. 6943 63.5 57.4 20.4% 57.8%. (b). 255-302. 6778 62.3 41.9 16.4% 51.5%. (c). 187-207. 2100 46.6 - 25% 59.1% | ||