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).
Measuring and damping wheel wobbles and vibrations on Phantom and Silver Ghost models.
| Identifier | ExFiles\Box 28\4\ Scan317 | |
| Date | 1st August 1925 | |
| R.R. 493A (50m) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. -6- Expl. No. REF. Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG21. 8. 25. With regard to amplitude of these wobbles. We set our instrument to measure wobbles of over 8º only - we found that any severe wobble was measured. We feel that a really severe wobble would certainly have an amplitude of 11º or over. All the wobbles we have so far measured started with a period which coincided with the period of the wheel rev. Hydraulic damping. We have a number of experiments in hand with hydraulic dampers. We are arranging :- (a) To damp the steering hydraulically. (b) To damp the criss cross and parallel vibrations of the axle hydraulically by fitting Houdaille in lieu of the Standard RR. (c) To damp the criss cross vibration but not the parallel vibration by means of a hydraulic device. Other tests. We have the test re. the rigidity of the engine suspension in hand. We are repeating the test increasing the moment of inertia of the axle at its extremities. We are confirming the criss cross nature of the vibration and its amplitude by means of the chronograph. Phantom and Silver Ghost. You have asked us to compare the wobbling tendencies of the Phantom and Silver Ghost in terms of lbs. out of balance of the wheels. Our tests are not very satisfactory but on the two cars we are using we find that roughly 1 lb. out of balance on each Silver Ghost wheel gives the same effect as ½ lb. out of balance of the Phantom. We should say that it is impossible to get a standard of comparison of two types without trying a large number of cars. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||