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).
Comparative analysis of Buick, Cadillac, and Studebaker dampers, focusing on inertia and resonance.
| Identifier | ExFiles\Box 124\1\ scan0222 | |
| Date | 24th July 1939 | |
| -4- The Buick damper having a moment of inertia of .00603 slug ft2 was next tried and Fig. 8 shows this damper with varying degrees of stiffness. A rating of 129 lbs.ft.degree was found to be the best and this is shown compared to the B.80 in Fig. 9. The amplitudes occurring with the Buick are large because of the inadequate inertia of the damper. The original Buick was built up from laminations and in order to investigate whether or not the laminations themselves were contributing to the damping, a solid wheel was made. It had an inertia of .00625 slug ft.2 and the resonance curves for this and the laminated damper are given in Fig. 10, thus disproving this theory. The Cadillac damper was the next to be investigated and in this case the torsional characteristics of the damper cannot be altered and tuning has to be effected by varying the inertia. The torque plotted against deflection curve for this damper is linear with a slope of 140 lbs.ft.degree. The damper itself has an inertia of .0081 slug ft2 and with a ring added this figure becomes .012 slug ft2. Fig. 11 shows the resonance curve for the damper without the ring as this is the best and is very nearly in tune. As can be seen this damper gives larger amplitudes at resonance than any of those previously tested and is more applicable to a constant speed or limited speed range machine than to one whose speed at full power has to vary over such a wide range as in our case. This is because the energy absorption is solely by hysteresis in the rubber material and this cannot be detected by our torque deflection apparatus. Of the dampers tried the smallest amplitudes are produced by the B.80 damper, but this is very unreliable and unsound mechanically. For damping properties the studebaker follows it closely and up to the present this damper has run many hours without giving any mechanical troubles. | ||