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).
Crankshaft torsion test results for a 20 HP shaft, from forging to finished product.
| Identifier | ExFiles\Box 6\1\ 01-page096 | |
| Date | 9th December 1927 | |
| To R.{Sir Henry Royce} from Ha/Tsn. c.c. to SJ. MOT. c.c. to RJ. S. c.c. to HY.{Tom Haldenby - Plant Engineer} X5010 Ha/Tsnl/LCS9.12.27. CRANKSHAFT TORSION TESTS. XIV-18 Further to Ha/Es/LCS.12.27. and Ha/Tsn/LCS.12.27 we are now giving fully the results of our crankshaft torsion tests with 20 HP. shaft and others. 20 HP. Crankshaft - Forging to finished shaft. The attached table gives the test results. The shaft was supported throughout these operations in the two end bearings only, and the torsional deflections measured where the difference between the front and rear deflection. The machining stages are chosen to show the effect of single operations, such as reducing the journal dia., profiling webs, boring the pins etc. Owing to the difficulty of supporting a rough forging in bearings, we started at op.15. where three of the journals are rough-turned. Curve 1. on graph 1. was extrapol-ated to show the stiffness of the unturned forging. The other curves are - curve 2 op.19 - curve 3 op. 21. - curve 4 op. 22 - curve 5 op. 31 - curve 6 and 7 are op. 33A separated so that (approx.) - curve 6 shews effect of profiling the webs - curve 7 shews effect of reducing the pins - curve 8 oper. 39A. In the attached table, the measured stiffnesses shown are for the shaft supported in two bearings, when tests shew it to be about 7% weaker than in 7 bearings. The calculated stiffnesses (Carters formula) are for the shaft supported in 7 bearings. contd :- | ||