Equaliser shafts should compensate the mass-forces that come about due to the different connecting rod positions.
How it works
From the front (not at the power-output side) there are two shafts, above to the left, and below to the right, rotating opposite the direction of the crankshaft, with double its speed. They carry counter-weights,
compensating agitating movements from the crankshaft or the connecting rods.
Some engines have these equaliser shafts positioned between the crankshaft and the oil sump. The equaliser shaft's gear wheel-
drive might be in the middle of the crankshaft. (see picture)
The ratio of the equaliser shaft to the crankshaft, its direction of rotation, the number of shafts, and its position may vary (picture 2).
|Four-cylinder running almost as quiet as a six-cylinder.|