DK28 diesel engine accessory exhaust rocker shaft 

The rocker arm is part of the valve mechanism in an engine, responsible for opening and closing the valves. The camshaft drives the rocker arm rod, which is a device that pushes the intake and exhaust valves to open at the right time. It cooperates with the camshaft to open the valves at the right moment, completing the intake and exhaust processes of the engine. 

The function of the rocker arm is to change the direction of the motion and force transmitted from the push rod and the cam, and then pass them on to the valve to make it open. During the swinging process, the rocker arm bears a large bending moment, so it should have sufficient strength, rigidity and a relatively small mass. The rocker arm is made of forged steel, malleable cast iron, ductile iron or aluminum alloy. The rocker arm is a double-arm lever, with the rocker shaft as the fulcrum, and the two arms are of unequal length. The short arm end is machined with threaded holes, which are used to screw in the valve clearance adjustment screws. The long arm end is machined into an arc surface, which is the working surface for pushing the valve. 

The function of the exhaust rocker arm for marine diesel engine components on the diesel engine 

When the engine crankshaft rotates, the camshaft also starts to rotate. There are many protrusions that deviate from the center on the camshaft, corresponding to each rocker arm. The rocker arm corresponds to the valve. When the protrusion moves downward, the valve rocker arm or the hydraulic tappet on the lower part will act under the pressure, and then pass on the force from the camshaft to the valve. At this time, the valve moves downward under the action of the downward pressure to complete the opening of the exhaust channel of the cylinder. When the protrusion on the camshaft makes a half-circle movement and moves upward, the valve will rise under the counterforce of the valve spring to complete the work of closing the exhaust passage.