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).
Calculation of the weight and polar moment of inertia for various engine components.
| Identifier | ExFiles\Box 65\4\ scan0167 | |
| Date | 4th November 1926 guessed | |
| contd :- -2- PART. WEIGHT. lbs. POLAR MOMENT OF INERTIA. (W/g K^2) Crankshaft complete - 75.875 .06738 units. Big end of conn. rod (2.64 lbs. each - total for six) - 15.84 .02579 " Spring drive parts - 14.125 .01437 " Flywheel complete with clutch - 168.25 1.384 " The spring drive parts do not include the slipper wheels because being free to slip they do not add to the polar inertia in this case. The equivalent rotating weight of the conn. rods was found approximately by weighing the big ends while supporting the other end horizontally and they were of the loose shell type. Having determined the stiffness of the shaft and the inertia of the parts, we were able to estimate the fundamental or free period of oscillation of the system, also the position of the nodal point - by calculation. The nodal point depends upon the disposition and inertia of the various masses and in this particular case works out at 1.6" from the flywheel end. As the node is situated so near to the flywheel we can, without introducing any serious error, assume the inertia of the crankshaft to be replaced by an equivalent mass at the front end. This equivalent mass would then have one-third the total inertia of the crankshaft and would be added to the inertia of the spring drive. contd :- | ||