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).
Page analysing connecting rod dynamics using the principles of a reversible compound pendulum.
| Identifier | WestWitteringFiles\M\2October1924-December1924\ Scan7 | |
| Date | 6th October 1924 | |
| Contd. -11- It therefore appears desirable to arrange for this condition as nearly as is convenient in other respects. This makes the con. rod proportionately heavier at the big end than usual. ab is equal to k², Mx{John H Maddocks - Chief Proving Officer} equal to Mx{John H Maddocks - Chief Proving Officer}, Mp equal to Mp, and Mg is zero. The con. rod in this case satisfies the condition of a reversible compound pendulum in which the centres of suspension and oscillation, in this case the crosshead centre X and the crankpin centre P respectively are interchangeable (i.e. without alteration of period of swing). The length of the simple equivalent pendulum is the length a + b of the con. rod, and when the con. rod is suspended to swing about either centre it will swing with the same period as that pendulum. The extent to which any actual con. rod dissatisfies this condition can readily be found by suspending the rod in turn from either centre and taking its period of swing, having previously made statical observations on the position of the centre of mass G, and therefore of the lengths a and b. In either case the length of the simple equivalent pendulum may be found and the value of k² deduced therefrom. The ratio (ab - k²)/k² is then a measure of the deviation. Contd. | ||