Optimal settings and design considerations for slipper wheels to achieve the best performance.
| Identifier | ExFiles\Box 11\2\ 02-page284 | |
| Date | 20th July 1929 | |
| 130 Hôtel de France, Châteauroux, Indre. To Hs. {Lord Ernest Hives - Chair} From G.W.H. Re Slipper wheels. I promised Rm. {William Robotham - Chief Engineer} to give you full details of the slipper wheel setting which I have found to give the best results. In the first place it is necessary to get the maximum peripheral inertia of the wheels that is possible. The remainder of the wheels should be as light as possible. The cutting down of the dia. as on the S.S. resulted in a loss of peripheral weight and we get a slipper wheel that is jerky in action, which produces the galloping knocks, also engine gear rattles, and does not damp out crankshaft periods. Our experience of the S.S. slipper wheels which is smaller in diameter with thicker and broader rims, making the wheels as heavy in proportion to the Phantom, is not effective and makes the engine very rough at the critical speeds, also produces engine gear periods of rattle. If we make the wheels larger in dia. and get the weight in the rim, we get them to slip easily and evenly. An important feature is that the springs for the slipper wheels must not be high rated and should be almost choc-a-block; the slipping load must not exceed 14 lbs, i.e. with the present S.S. drilled and filled with lead. Present springs used on S.S. will give this feature. The idea of the springs being practically choc-a-block is to prevent the flywheels expanding, which causes them to run out of truth, also a danger of jamming on the spigot. I have seen definitely on one S.S. where the wheels had expanded and rubbed on the wheel case. G.W.H. | ||
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).