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| Illustration 1 | g06414548 |
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(1) Hydraulic tank
(2) Hydraulic filters (3) Left-hand diverter valve (4) Right-hand diverter valve | |
The hydraulic system consists of a hydraulic reservoir / tank that supplies oil to hydraulic pumps. These hydraulic pumps provide hydraulic pressure to operate all machine functions outside of the electrical and compressed air circuits. From the pumps oil is supplied to the control valves which operate hydraulic motors or cylinders. Another important feature of hydraulic systems is the filters. The hydraulic system consists of closed loop and open loop systems. The two closed loop systems have separate main pumps that control the travel and drill circuits. The open loop system consists of the necessary pumps, cylinders, and controls to prepare and position the drill for operation. The left-hand travel and rotation pump controls the left travel circuit motor and the hoist and pull-down cylinder. The right-hand pump controls the right travel motor, and the drill rotation motor. All the oil returning to the tank flows through either the return manifold, the drain manifold, or the case drain manifold. Oil returning from the return manifold must pass through the return filter before entering the tank. Oil returning from the drain and case manifolds must pass through the case drain return filter. Both these filters have by-pass check valves in case the filters become blocked.
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| Illustration 2 | g06260650 |
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(1) Hydraulic tank
(2) Return filters | |
The hydraulic tank (1) is located on the right side of the machine on the right walkway platform and contains the two return filters (2).
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| Illustration 3 | g06364959 |
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(3) Left-hand diverter valve
(4) Right-hand diverter valve | |
There are two diverter valves in the hydraulic system, the left-hand diverter valve, and the right-hand diverter valve. The left-hand diverter valve supplies oil to the left travel circuit while in travel mode, and to the hoist / pull-down circuit in drill mode. The right-hand diverter valve supplies oil to the right travel circuit while in travel mode, and to the rotation circuit in drill mode.
The two diverter valves are two position, six port, pilot operated directional valves. The valves are sprung into travel mode, and are pilot controlled by charge pressure to shift into drill mode. The spring chamber end cap is drained to prevent the possibility of a pressure lock.