Necessity and methods for balancing propeller shafts on the Phantom III model.
| Identifier | ExFiles\Box 94\4\ scan0114 | |
| Date | 1st May 1936 | |
| To E. {Mr Elliott - Chief Engineer} c. to Wor. {Arthur Wormald - General Works Manager} c. to Da. {Bernard Day - Chassis Design} c. to Hdy. {William Hardy} c. to By. {R.W. Bailey - Chief Engineer} c. to Hx. c. to Sft. {Mr Swift} 4337 Hs {Lord Ernest Hives - Chair} /Gry. {Shadwell Grylls} 5/KW.1.5.36. Propellor Shafts - Phantom III. Reference to Hs {Lord Ernest Hives - Chair} /Gry. {Shadwell Grylls} 3/KW.17.9.35 will show that we emphasized the necessity of balancing Phantom III propellor shafts sufficiently accurately to prevent roughness from unbalance being felt in the car. Owing to a recent epidemic of trouble on experimental cars we have gone further into the matter. 32-KX was recently fitted with a shaft supplied by the Works, balanced on the production rig. The vibration at high speed on the car was excessive. No car could leave the Works in this condition. By trial and error this shaft has been made a satisfactory job. We were present while this was balanced in the Works, and whereas it ran smoothly at about 3,000 r.p.m., while slowing down it shook violently at the critical speed of the bed. Until shafts are balanced accurately in the Works it will be necessary to do this on each car by trial and error, running up to 85 m.p.h. with the rear wheels jacked up. When we had similar trouble on Peregrine(Experimental Bentley car never produced / Aero Engine) propellor shafts we obtained the Trebel balancing machine and demonstrated that this would balance shafts sufficiently accurately for Peregrine(Experimental Bentley car never produced / Aero Engine) conditions. We consider that it is time the Works were able to use this machine, since balancing by this method would save considerable time over doing each shaft independently on the car. The apparatus shown on the attached photograph enables this job to be done in about one hour per car, washers being added where indicated until a suitable flange is provided for drilling, as on the Bentley. Only the front end need be balanced accurately, and before doing so the front joint must be completely full of lubricant. A shaft that is in balance full of lubricant can be very rough if only half full. | ||
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).