HAMMER GP- 4Z8969 - Caterpillar

Hydraulic Schematic with Heavy Lift
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Partial schematic
(13) Main control valve
(29) Pilot oil manifold
(34) Main relief valve
(38) Hydraulic tank
(43) Pilot pump
(46) Heavy lift solenoid Hydraulic Schematic with Fine Swing
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Partial schematic
(5) Swing motor
(13) Main control valve
(38) Hydraulic tank
(47) Fine swing solenoid Hydraulic Pump Flow and Pressure Control System
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Pump compartment
(42) Idler pump
(43) Pilot pump
(44) Drive pump
(48) Delivery line (drive pump)
(49) Delivery line (idler pump) This machine is driven and controlled by the following systems.
The main hydraulic system controls the cylinders, the travel motors, and the swing motor.
The pilot hydraulic system supplies oil to the main control valve, the joysticks, the travel pedals, the swing brake, and the travel motors.
The electronic control system controls the outputs of the engine and pumps.The main hydraulic system delivers oil flow from idler pump (42) and drive pump (44) in order to control the following components: bucket cylinder (1), stick cylinder (2), boom cylinders (3), right travel motor (7), left travel motor (6) and swing motor (5).
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Main control valve
(34) Main relief valve
(50) Main control valve body Drive pump (44) and idler pump (42) are electronically controlled variable displacement piston pumps. The performance of both pumps is equal.Drive pump (44) is directly connected to the engine by a flexible coupling. Idler pump (42) is mechanically connected to the drive pump through gears. The drive pump and the idler pump deliver oil to main control valve body (50). The drive pump delivers oil to the left travel control valve, the boom l control valve, the bucket control valve and the stick II control valve. The idler pump delivers oil to the right travel control valve, the boom II control valve, the swing control valve and the stick l control valve. Pilot pump (43) is a gear pump that supplies oil to the pilot hydraulic system. Pilot pump (43) is mechanically connected to drive pump (44) through gears. All engine output is used to drive these three pumps.As the load pressure increases during working conditions, the main pumps increase the delivery pressure and the pumps decrease the flow rate. The hydraulic horsepower remains constant even though the delivery pressure and the flow rates change. The hydraulic horsepower is identical to the engine horsepower.When no work is being performed, pump oil flows through main control valve (13) and into hydraulic tank (38). The main control valve generates a negative flow control (NFC) signal pressure. This signal is sensed by NFC pressure sensors (9) and (12). The machine ECU sends a PWM driver to each pump regulator in order to destroke the pumps to the minimum output flow.If an operation is being performed, main control valve (13) directs pump oil to the respective cylinders (boom, bucket and stick) and/or motors (swing and travel). Main control valve (13) contains numerous valve stems, passages, check valves, orifices and electronic solenoids to carry out a single operation or a combined operation. The working pressure of the main hydraulic system is regulated by main relief valve (34).
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Cab
(51) Monitor panel
(52) Joystick (stick