crank assembly

The crank assembly features a balancer shaft. Its task is to reduce oscillations and thus to achieve smooth engine running.

The balancer shaft runs in the bottom part of the cylinder block and is driven through two gears by the crankshaft. The balancer shaft rotates in the opposite direction of the crankshaft at engine speed.

The up and down movements of the pistons and conrods produce forces which cause oscillations.
These oscillations are transmitted through the assembly mounting to the body.
The task of the balancer shaft is to counteract the forces produced by the pistons, conrods and crankshaft in order to minimize such oscillations.

CRANKSHAFT



The crankshaft, sometimes usually abbreviated to crank , is the part of an engine that translates reciprocating linear piston motion into rotation. To convert the reciprocating motion into rotation, the crankshaft has "crank throws" or " crankpins", additional bearing surfaces whose axis is offset from that of the crank, to which the
"big ends" of the connecting rods from each cylinder attach.

Huge crankshaft of a ship engine.