SMCS Code: 4306; 4306-GE
Part No.: 143-3521
(1) Bleed orifice. (2) Priority Valve. (3) Plot signal passage. (4) Pump gears. (5) Relief Valve. (6) Charge oil outlet.
The gear pump is a fixed displacement pump that is mounted
to the accessory drive on the engine. The gear pump supplies
oil to the steering system. The gear pump also provides
charge oil for the propel system and the vibratory system.
Priority valve (2) is a pressure compensated flow divider. The
priority valve divides the flow between the steering circuit and
the charge circuit. The steering circuit has priority, and the
return flow from the steering circuit returns into the charge
Relief valve (5) empties into the inlet of the steering pump.
The relief valve is the pressure relief for the steering cylinders.
Output oil from pump gears (4) of the gear pump acts against
the lower end of priority valve (2). Oil goes through bleed
orifice (1) and the passage in the priority valve. Oil pressure
forces priority valve (2) upward in order to allow oil flow to
charge oil outlet (6).
Oil from the metering pump enters pilot signal passage (3).
This oil acts against the upper end of the priority valve in
addition to the force of the spring pressure. The pilot signal oil
also acts against relief valve (5). The relief valve empties into
the pump inlet and the relief valve serves as the pressure relief
for the steering cylinders.
Bleed orifice (1) serves as a flushing passage for the oil that
puts pressure on the bottom of the priority valve. The bleed
orifice minimizes the bottoming of the priority valve against
each stop. During operation, the priority valve oscillates.