GEAR GP-REAR 2795635 - Caterpillar

Bucket Close
Illustration 1 g03810939
Hydraulic schematic (BUCKET CLOSE)
(1) Bucket cylinder
(2) Flow compensator valve
(3) Pump supply passage
(4) Port
(5) Port
(6) Main control valve
(7) Pilot control valve (boom and bucket)
(8) Pilot oil line (bucket close)
(9) Pilot oil line (bucket open)
(10) Load check valve
(11) Load check valve
(12) Return passage
(13) Bucket control valve
(14) Main pump
(15) Pilot manifold
Illustration 2 g02293389
Bucket control valve (BUCKET CLOSE)
(2) Flow compensator valve
(3) Pump supply passage
(4) Port
(5) Port
(10) Load check valve
(11) Load check valve
(12) Return passage
(13) Bucket control valve
(16) Pilot port
(17) Pilot port
(18) Spool When pilot control valve (7) is moved for a BUCKET CLOSE operation, pilot oil flows from pilot control valve (7) to the bucket control valve. The pilot oil is directed to pilot port (16). Pilot oil then shifts spool (18) of bucket control valve (13) to the right.Supply oil is routed from pump (14) to main control valve (6). The supply oil flows to pump supply passage (3) and through bucket control valve (13). Pump oil then flows through flow compensator valve (2), load check valve (10), and to port (4). This action causes the cylinder rod to extend. The extension of the cylinder rod causes the bucket to close.Return oil from the rod end of the bucket cylinder flows through port (5) and to return passage (12). The oil in return passage (12) then flows to the return hydraulic system and the hydraulic tank.Bucket Open
Illustration 3 g03810947
Hydraulic schematic (BUCKET OPEN)
(1) Bucket cylinder
(2) Flow compensator valve
(3) Pump supply passage
(4) Port
(5) Port
(6) Main control valve
(7) Pilot control valve (boom and bucket)
(8) Pilot oil line (bucket close)
(9) Pilot oil line (bucket open)
(10) Load check valve
(11) Load check valve
(12) Return passage
(13) Bucket control valve
(14) Main pump
(15) Pilot manifold
Illustration 4 g02295614
Bucket control valve (BUCKET OPEN)
(2) Flow compensator valve
(3) Pump supply passage
(4) Port
(5) Port
(10) Load check valve
(11) Load check valve
(12) Return passage
(13) Bucket control valve
(16) Pilot port
(17) Pilot port
(18) Spool When the pilot control valve (joystick) is moved for a BUCKET OPEN, pilot oil flows from pilot control valve (7) to the bucket control valve. The pilot oil is directed to pilot port (17). Pilot oil then shifts spool (18) of bucket control valve (13) to the left.Supply oil is routed from pump (14) to main control valve (6). The supply oil flows to pump supply passage (3) and through bucket control valve (13). Pump oil then flows through flow compensator valve (2), load check valve (11), and to port (5). This action causes the cylinder rod to retract. The retraction of the cylinder rod causes the bucket to open.Return oil from the head end of the bucket cylinder flows through port (4) and to return passage (12). The oil in return passage (12) then flows to the return hydraulic system and the hydraulic tank.Refer to the Systems Operation, "Main Control Valve" for more information on the main control valve and the bucket control valve.