Section III. PRINCIPLES OF OPERATION
This section explains how major components in the RT875CC Container Crane work by providing a functional description
and the theory of operation for each system's organizational level component.
ENGINE LUBRICATING SYSTEM
Oil flow begins as the gerotor type oil pump pulls oil from the oil pan through the rigid, internally mounted suction tube.
The oil pump then delivers the oil through an internal drilling in the cylinder block to the oil pressure regulator, which is
located in the oil cooler cover.
Pressure Regulating Valve
The pressure regulating valve relieves oil pressure during cold starting and regulates oil pressure after the oil is warm.
The regulator valve remains closed until the oil pressure is approximately 315 kPa (45 PSI). When the oil pressure is
greater than 315 kPa (45 PSI), the valve begins to open and pressure is relieved by allowing some of the oil to return to
the pan. The valve plunger has a tapered shoulder which creates a variable opening to regulate the pressure.
From the regulator cavity, the oil flows through the cooler cover and cooler element. Coolant flowing past the plates of the
element cools the oil.
Filter Bypass Valve
The oil cooler cover contains a bypass valve that will let the oil flow bypass a plugged oil filter. If the pressure drop across
the oil filter exceeds 138 kPa (20 PSI), the bypass valve will open, allowing the oil to continue through the engine.
From the cooler, the oil flows through a passage in the cooler cover to the oil filter. The filtered oil flows up to the center of
the filter to the filter head.
Turbocharger and Cylinder Block
At the filter head, the oil flow is divided: A portion flows to the turbocharger; the rest flows down a passage in the cylinder
block that connects to a cross drilling over the number 3 main bearing.