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 discussing the linear and angular accelerations of a connecting rod for engine balancing.
| Identifier | WestWitteringFiles\M\2October1924-December1924\ Scan15 | |
| Date | 25th October 1924 guessed | |
| -3- Contd. because by supplying these effective forces by the inertia actions of other moving masses, we balance the body. (4) The linear accelerations of the centre of mass of a con. rod in the direction of piston motion and at right angles thereto respectively, also the angular acceleration of the con. rod can readily be found. Then, knowing its mass and its moment of inertia about the axis through its centre of mass, all the effective forces would be immediately deducible. This simple statement of the case, however, is not simple from a balancing point of view, because the required linear force (or forces) acting at the centre of mass, is (are) not suitably situated as regards its line (their lines) of action, and if this force is (these forces are) balanced linearly in the usual way, by revolving and reciprocating masses, the balancing forces are not in the same lines of action and a couple is introduced in addition to the simple inertia couple exerted by the rod about the axis through its centre of mass. This means that though the linear balance of the con, rod is carried out correctly as explained in previous notes on balancing, the unbalanced couple due to the con. rod is <u>not</u> represented simply by its moment of inertia multiplied by its angular acceleration. Instead, the departure from this simple expression is repres- ented by the algebraic sum of the moments of the two component linear acceleration forces at the centre of mass, about the crankshaft axis of the engine. This method of dealing | ||