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).
Balancing inconsistencies found in propeller shaft dampers, particularly on the Phantom III model.
Identifier | ExFiles\Box 94\4\ scan0149 | |
Date | 16th April 1937 | |
1262 337 To RHC.{R. H. Coverley - Production Engineer} from Rm{William Robotham - Chief Engineer}/Smth. c. HS.{Lord Ernest Hives - Chair} c. By.{R.W. Bailey - Chief Engineer} c. HPS.{Horace Percy Smith - Experimental Factory Mgr} Rm{William Robotham - Chief Engineer}/Smth.10/AP.16.4.37 PROPELLER SHAFT DAMPERS We have been troubled by inconsistency of balance in propeller shaft dampers. Propeller shaft assemblies which have been carefully balanced by the standard method have periodically become badly out of balance. This trouble has been particularly noticeable on Phantom IIIs. fitted with transmission dampers, and as a Depot Sheet has been issued instructing dampers to be fitted to customers' cars in certain instances, we have been investigating the matter. Our present method of balancing the damper, which is to balance the complete assembly by drilling the inertia rings, depends on absolute concentricity between the fixing spigot and the flywheel journals. If these two diameters are eccentric the damper cannot be in balance for all angular positions of the rings, unless the rings are themselves in balance. The trouble has been due to this source. On inspecting a number of hubs we found that they were badly eccentric - as much as .007" in some cases. Mr.Goodall says that the tolerance is only .0015" and is taking the matter up. Even with this limit, however, we shall still run into trouble unless the rings and hub are separately balanced, and this procedure should immediately be introduced on Production. In particular no dampers should be sent for Phantom IIIs. which have not been balanced by this method. Rm{William Robotham - Chief Engineer}/Smth. | ||