834G Wheel Tractor
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| Illustration 1 | g00847350 |
Hydraulic Schematic for the Hydraulic Fan System | |
The hydraulic fan system consists of the following components: hydraulic fan motor (1), makeup valve (2), hydraulic cooler bypass valve (3), hydraulic oil cooler (4), hydraulic fan pump (5), Thermostatic valve (6), oil filter (7) and hydraulic tank (8) .
Hydraulic fan pump (5) is a variable displacement axial piston pump. Hydraulic fan pump (5) is mounted to the front engine housing on the right side of the machine.
While the engine is operating, hydraulic fan pump (5) draws hydraulic oil from hydraulic tank (8) and hydraulic fan pump (5) supplies hydraulic oil to hydraulic fan motor (1).
The hydraulic fan is attached to hydraulic fan motor (1) and installed on the outside of the radiator. Hydraulic fan motor (1) is a gear motor. The hydraulic fan draws air through the top of the hood and the side panels during normal operation. Air exits through the rear of the machine.
The return oil of hydraulic fan motor (1) flows to hydraulic oil cooler (4). The hydraulic oil then flows back to hydraulic tank (8). Hydraulic cooler (4) is located between the radiator and the engine.
When the hydraulic oil is cold, return oil from hydraulic fan motor (1) cannot easily flow through hydraulic oil cooler (4). The hydraulic oil pressure forces the hydraulic oil cooler bypass valve (3) to open. When hydraulic oil cooler bypass valve (3) is open the hydraulic oil flows back to hydraulic tank (8). As the hydraulic oil temperature increases, more hydraulic oil flows through hydraulic oil cooler (4) and the hydraulic oil pressure decreases. When the hydraulic oil pressure drops below the spring pressure of the bypass valve, hydraulic oil cooler bypass valve (3) closes. When hydraulic oil cooler bypass valve (3) closes, oil flows through hydraulic oil cooler (4) to hydraulic tank (8) .
Thermostatic valve (6) is used to control fan speed when engine coolant temperature begins to increase. Thermostatic valve (6) is open when the engine coolant temperature is lower than approximately 70 °C (158 °F). When the thermostatic valve is open the load signal oil for the hydraulic fan pump (5) will drain into the case drain return line. When engine coolant temperature is above 70 °C (158 °F), thermostatic valve (7) begins to close. Thermostatic valve (6) is fully closed when engine coolant temperature is approximately 90 °C (194 °F). When thermostatic valve (6) is closed, the load signal pressure for hydraulic fan pump (5) will increase to a higher pressure and the hydraulic fan pump (5) will upstroke.
836G Landfill Compactor
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| Illustration 2 | g00559087 |
Hydraulic Schematic for the Fan Drive System (1) Hydraulic fan motor. (2) Hydraulic fan reversing valve. (3) Hydraulic oil cooler bypass valve. (4) Hydraulic oil cooler. (5) Hydraulic fan pump. (6) Thermostatic valve. (7) Hydraulic oil tank. | |
The hydraulic fan system consists of the following components: hydraulic fan motor (1), hydraulic fan reversing valve (2), hydraulic oil cooler bypass valve (3), hydraulic oil cooler (4), hydraulic fan pump (5), thermostatic valve (6) and hydraulic tank (7) .
Hydraulic fan pump (5) is a variable displacement axial piston pump. Hydraulic fan pump (5) is mounted to the front engine housing on the right side of the machine.
While the engine is operating, fan pump (5) draws hydraulic oil from hydraulic tank (7) in order to supply hydraulic oil to fan motor (1) .
The hydraulic fan is attached to hydraulic fan motor (1) and installed on the outside of the radiator. Hydraulic fan motor (1) can be a bidirectional gear motor or a bidirectional piston motor.
The hydraulic fan draws air through the top of the hood and the side panels during normal operation. Air exits through the rear of the machine. After approximately thirty minutes of operation, a solenoid valve in the hydraulic fan reversing valve (2) is energized.
Hydraulic fan reversing valve (2) reverses the flow of hydraulic oil to the hydraulic fan motor (1). The reverse flow of hydraulic oil will cause the hydraulic fan motor to rotate in the reverse direction.
When the rotation of the hydraulic fan is reversed, the hydraulic fan pushes air through the radiator, the top of the hood and the side panels. The change of air flow will help remove debris that collects on the top of the hood and the side panels. The hydraulic fan rotates in the reverse direction for approximately thirty seconds.
The return oil of fan motor (1) flows to hydraulic oil cooler (4). The hydraulic oil then flows back to hydraulic tank (7). Hydraulic cooler (4) is located between the radiator and the engine.
When the hydraulic oil is cold, return oil from fan motor (1) cannot easily flow through hydraulic oil cooler (4). The hydraulic oil pressure forces the hydraulic oil cooler bypass valve (3) to open. When hydraulic oil cooler bypass valve (3) is open the hydraulic oil flows back to hydraulic tank (7). As the hydraulic oil temperature increases, more hydraulic oil flows through hydraulic oil cooler (4) and the hydraulic oil pressure decreases. When the hydraulic oil pressure drops below the spring pressure of the bypass valve, hydraulic oil cooler bypass valve (3) closes. When hydraulic oil cooler bypass valve (3) closes, oil flows through hydraulic oil cooler (4) to hydraulic tank (7) .
Thermostatic valve (6) is used to control fan speed when engine coolant temperature begins to increase. When the engine coolant temperature is less than approximately 70 °C (158 °F), thermostatic valve (6) is open.
When thermostatic valve (6) is open, the load signal oil for hydraulic fan pump (5) will drain into the case drain line.
When engine coolant temperature is above 70 °C (158 °F), thermal relief valve (6) starts to close. Thermostatic valve (6) is fully closed when engine coolant temperature is approximately 90 °C (194 °F).
When thermostatic valve (6) is closed, the load signal pressure for hydraulic fan pump (5) will increase to a higher pressure and the hydraulic drive pump (5) will upstroke.