MARINE GEAR ARRANGEMENT 5N2922 - Caterpillar

Illustration 1 g02428457
Valve system components
(1) Valve spring
(2) Rotocoil
(3) Valve bridge assembly
(4) Rocker arm
(5) Rocker shaft assembly
(6) Pushrod
(7) Valve lifter
(8) Camshaft
(9) Camshaft lobes Camshaft (8) is rotated through the rear gear train by the crankshaft. The rotation of camshaft is precisely timed to the rotation of the crankshaft. This timing ensures that the correct relation between the movement of the piston and the movement of the valves is maintained.Two lobes (9) are machined into the camshaft for each cylinder. One lobe operates the valve mechanism components for the inlet valves and the other lobe operates the valve mechanism components for the exhaust valves.As the camshaft rotates, the rollers on valve lifters (7) travel up the camshaft lobes. Pushrod (6) transfers this motion to rocker arm (4). The rocker arms pivot on rocker shaft assemblies (5). The rocker arms act as a lever as the motion is transferred to the top of valve bridge assembly (3). The valve bridge assemblies transfer movement from the rocker arms to the top of the valve stems. The bridge assemblies operate two valves simultaneously. There is a pair of intake valves and a pair of exhaust valves for each cylinder.Rotocoils (2) initiate a rotational movement to the valves as the valves are opened and closed. The rotation of the valves keeps the carbon deposits on the valves to a minimum which gives the valves a longer service life.Valve springs (1) are used to provide a spring tension force on the valves. This force causes the valves to close as the lifters travel off the camshaft lobe.