VALVE-REFRIGERANT EXPANSION 1226015 - Caterpillar

Illustration 1 g00729315
(1) Rocker arm assembly (2) Main engine oil gallery (3) Drilled passage in the cylinder block between the main engine oil gallery and the camshaft bearings (4) Tube (5) Drilled passage in the cylinder block between the camshaft bearings and the cylinder head (6) Gallery for the right piston cooling jets (7) Gallery for the left piston cooling jets (8) Outer piston cooling jet (9) Inner piston cooling jet (10) Drilled passage in the cylinder block between the main engine oil gallery and the crankshaft main bearings
Illustration 2 g00729316
Cylinder Head (4) Tube (11) Valve lifter guideThe camshaft bearings receive engine oil from main engine oil gallery (2) through drilled passages (3) in the cylinder block. The engine oil flows around each camshaft journal. Then, the engine oil flows through a drilled passage in cylinder block (5) to valve lifter guide (11) and to tube (4). Engine oil then flows through the tube to the cylinder head and to rocker arm assembly (1) .Main engine oil gallery (2) is connected to the crankshaft main bearings by drilled passage (10) in the cylinder block. Drilled holes in the crankshaft connect the main bearing oil supply to the connecting rod bearings.When the pressure in the system reaches 140 kPa (20 psi), the priority valve allows engine oil into the engine oil galleries for the right and left piston cooling jets (6) and (7). Inner piston cooling jets (9) receive engine oil at all times. The priority valve prevents engine oil from entering the galleries for the piston cooling jets until there is pressure in main engine oil gallery (2). This reduces the time that is required to build up pressure when the engine is started. This also helps maintain pressure at low idle rpm.Engine oil flows through a port in the top rear of the cylinder block into supply lines for the turbochargers. The turbocharger's drain lines return the engine oil through the rear housing.Engine oil is provided to the front gear groups and to the rear gear groups through tubes and through drilled passages in the front and rear housings. After the engine oil has provided lubrication, the engine oil returns to the engine oil sump.