The combined function hydraulic system combines the features of one-way hydraulics and two-way hydraulics. This combination allows one-way work tools (hydraulic hammer) and two-way work tools (hydraulic shear) to be used interchangeably on the same machine.
One-Way Hydraulic System
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| Illustration 1 | g02160586 |
Simplified Hydraulic Schematic (A) TWO-WAY position (B) ONE-WAY position (1) Relief valve (one-way system) (2) Line (3) Ball valve (4) Ball valve (5) Line (6) Line (7) Main control valve (8) Proportional reducing valve (9) Line (one-way return) (10) Passage (pump delivery flow) (11) Line relief valve (12) Passage (13) Attachment control valve (14) Passage (pump delivery flow) (15) Flow compensator valve (16) Load check valve (17) Line relief valve (18) Passage (19) Proportional reducing valve (20) Delivery line (rear pump) (21) Delivery line (front pump) (22) Hydraulic tank (23) Pilot pump (24) Line (pilot oil supply) (25) Front pump (26) Rear pump (27) Pilot manifold (28) Line (pilot oil flow) | |
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| Illustration 2 | g02160783 |
Ball valves are shown in ONE-WAY position. (3) Ball valve (4) Ball valve (1) Relief valve (one-way system) | |
Pilot pump (23) sends pilot system oil through line (24) to pilot manifold (27). The pilot system oil then flows through line (28) to proportional reducing valve (8) and proportional reducing valve (19) .
When the work tool control is operated, an electrical signal from the control is sent to the machine ECM. The machine ECM energizes proportional reducing valve (8) .
When proportional reducing valve (8) is energized, the spool in attachment control valve (13) shifts upward. The oil delivery from the main pumps flows from passage (10) through attachment control valve (13), load check valve (16), flow compensator valve (15), passage (14) and passage (18). The oil delivery from the main pumps in passage (18) now flows through line (5) to the work tool.
The return oil from the work tool flows through line (6) and returns through ball valve (4), line (2) and relief valve (1). The return oil in line (9) now flows back to the hydraulic filters and hydraulic tank (22) .
The pressure in the work tool is controlled by relief valve (1) .
Note: The pressure setting for the relief valves must be reset to the specification of the supplier for the work tool that is being used.
Two-Way Hydraulic System
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| Illustration 3 | g02160823 |
Simplified Hydraulic Schematic (A) TWO-WAY position (B) ONE-WAY position (1) Relief valve (one-way system) (2) Line (3) Ball valve (4) Ball valve (5) Line (6) Line (7) Main control valve (8) Proportional reducing valve (9) Line (one-way return) (10) Passage (pump delivery flow) (11) Line relief valve (12) Passage (13) Attachment control valve (14) Passage (pump delivery flow) (15) Flow compensator valve (16) Load check valve (17) Line relief valve (18) Passage (19) Proportional reducing valve (20) Delivery line (rear pump) (21) Delivery line (front pump) (22) Hydraulic tank (23) Pilot pump (24) Line (pilot oil supply) (25) Front pump (26) Rear pump (27) Pilot manifold (28) Line (pilot oil flow) | |
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| Illustration 4 | g02160826 |
Ball valves are shown in TWO-WAY position. (3) Ball valve (4) Ball valve (1) Relief valve (one-way system) (7) Main control valve (11) Line relief valve (two-way system) | |
Pilot pump (23) sends pilot system oil through line (24) to pilot manifold (27). The pilot system oil then flows through line (28) to proportional reducing valve (8) and proportional reducing valve (19) .
When the work tool control is operated, an electrical signal from the control is sent to the machine ECM. The machine ECM energizes proportional reducing valve (8) .
When proportional reducing valve (8) is energized, the spool in attachment control valve (13) shifts upward. The oil delivery from the main pumps flows from passage (10) through attachment control valve (13), load check valve (16), flow compensator valve (15), passage (14) and passage (18). The oil delivery from the main pumps in passage (18) now flows through line (5) to the work tool.
The return oil from the work tool flows through line (6), passage (12), and attachment control valve (13) to return line (29). The return oil now flows back to the hydraulic filters and hydraulic tank (22) .
Proportional solenoid valve (19) is energized instead of proportional solenoid valve (8) when the work tool is operated in the opposite direction. Attachment control valve (13) shifts downward and pump oil is sent through passage (12) to line (6). The pump oil in line (6) flows to the work tool.
The return oil from the work tool flows through line (5), passage (18), and attachment control valve (13) to return line (29). The return oil now flows back to the hydraulic filters and hydraulic tank (22) .
The line relief pressure in the work tool is controlled by relief valves (11) and (17) .
Note: The pressure setting for the relief valves must be reset to the specification of the supplier for the work tool that is being used.