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).
Torsional tests on a Phantom III steering rocker shaft to determine the maximum applicable torque.
| Identifier | ExFiles\Box 95\1\ scan0467 | |
| Date | 24th December 1937 | |
| F.{Mr Friese} J.{Mr Johnson W.M.} Hdy{William Hardy} See me Rm{William Robotham - Chief Engineer} To Rm{William Robotham - Chief Engineer}/Hdy.{William Hardy} from HPS{Horace Percy Smith - Experimental Factory Mgr}/W.Bell. HPS{Horace Percy Smith - Experimental Factory Mgr}/WB.{Mr Brazier/Mr Bell}3/CB.24.12.37. PHANTOM III STEERING ROCKER SHAFT. FB.83341 Rocker Shaft. Torsional tests were carried out on Phantom III Steering Rocker Shaft to determine the maximum torque applicable. With the rocker shaft secured at the centre line of the cam roller, gradually increased torques were applied to the pendulum lever until failure occurred. Three shafts were tested. (1) Test Shaft. This shaft had been used previously on the test rig when testing cam roller bearings and was a non heat-treated shaft, the Core Brinell being 174. Initial permanent set occurred at a torque of 600 lb. ft. and failure was fairly rapid from this point. (2) Spare Shaft. Brinell 226. Obtained from fitting section (being a spare replacement shaft) and tested as its Brinell was towards the lower limit. Initial permanent set occurred in this instance, at 1,000 lb. ft. and beyond this, torque failure occurred very rapidly. (3) 32 Ex Shaft. Brinell 293. This shaft had been previously fitted to 32 Ex chassis and was chosen since the Brinell number was towards the higher specified limit. Permanent set occurred at the same torque as in the spare shaft (1,000 lb. ft.) but the subsequent rate of increase of permanent set was more gradual. In all these tests, failure commenced at the tapered serrations at the inner edge of the pendulum lever (See attached chart). Max parking torque x 2.2. JH HPS{Horace Percy Smith - Experimental Factory Mgr}/W. Bell. W Bell | ||