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 from a technical paper on the linear balancing of a connecting rod.
| Identifier | WestWitteringFiles\M\2October1924-December1924\ Scan10 | |
| Date | 1st October 1924 | |
| EFC1/T6.10.24. -8- Contd. is generally (the exception in certain circumstances being indicated later) in the opposite direction to the couple, due to the acceleration of the con. rod itself about its centre of mass. This is because the linear balancing forces considered to be acting on the con. rod at the points X and P are equivalent not merely to some linear force acting through G, but also plus a couple about G, and this couple is actually larger than the effective couple acting on the con. rod to produce its angular acceleration about its centre of mass. In other words the linear balancing more than supplies the couple required by the con. rod. Supposing the linear balance is only effective up to the point of balancing M_x and M_p (instead of the usual M_x and M_p), then it should be clear that there would be no resulting out-of-balance couple due to the con. rod, but a simple out-of-balance linear force (proportional to M_g) whose line of action passes through G.{Mr Griffiths - Chief Accountant / Mr Gnapp} Whence it may be clear that the magnitude of the couple existing with complete linear balance must be that of a moment of inertia represented by a mass b/(a+b) M_g displaced through a distance a, together with a mass a/(a+b) M_g displaced Contd. | ||