ADJUSTER 1625602 - Caterpillar

Boom Lower (With Regeneration)
When the boom is lowered and the work tool is not touching the ground, the machine ECM allows for boom regeneration. The mass of the boom, stick, and work tool cause the head end of the boom cylinders to be pressurized. The pressure in the head end of the boom cylinders is higher than the pump output.Because the pressure in the head end of the boom cylinders is higher than the rod end of the boom cylinders, the excessive pressure is cycled back to rod end of the cylinders. Cycling the pressure oil back to the rod end of the boom cylinders reduces the load on the main pumps. Regeneration also prevents cavitation conditions in the rod end of the boom cylinders.
Illustration 5 g02198560
Hydraulic schematic for BOOM LOWER (with regeneration) (1) Boom cylinders (2) Line (oil flow to boom cylinder rod end) (3) Line (oil flow to boom cylinder head end) (4) Line (pilot oil supply) (5) Pilot manifold (6) Line (pilot oil flow to proportional solenoid valves) (7) Boom drift reduction / regeneration valve (8) Solenoid valve (boom drift reduction / regeneration valve) (9) Proportional solenoid valve (boom cylinder rod end) (10) Spool (boom drift reduction) (11) Passage (12) Main control valve (13) Bridge passage (14) Flow compensator valve (15) Load check valve (16) Boom control valve (17) Passage (pump delivery flow to rod end of boom cylinders) (18) Passage (pump delivery flow to boom drift reduction / regeneration valve) (19) Passage (pump delivery flow to boom control valve) (20) Return passage (21) Proportional solenoid valve (boom cylinder head end) (22) Passage (return pilot oil) (23) Line (return oil) (24) Pilot pump (25) Front pump (26) Rear pump
Illustration 6 g02198561
Boom drift reduction / regeneration valve partial schematic (1) Boom cylinders (2) Line (oil flow to boom cylinder rod end) (3) Line (oil flow to boom cylinder head end) (7) Boom drift reduction / regeneration valve (8) Solenoid valve (boom drift reduction / regeneration valve) (10) Spool (11) Passage (27) Spool (28) Passage (29) Passage (30) Check valve (31) Passage (32) PassageThe BOOM LOWER with regeneration operation is like the BOOM LOWER without regeneration operation.When the joystick for the boom is operated, an electrical signal from the joystick is sent to the machine ECM. The machine ECM energizes proportional solenoid valve (9). The machine ECM also energizes solenoid valve (8) .When proportional solenoid valve (9) (boom cylinder rod end) is energized, pilot oil shifts the spool in boom control valve (16). The oil delivery from front pump (25) and rear pump (26) flows from passage (19) through boom control valve (16) to load check valve (15). Pump oil then flows through flow compensator valve (14) to passage (13). Pump oil then flows through boom control valve (16) to passage (17). Pump oil in passage (17) then flows to line (3) and out to the rod end of boom cylinders (1) .The machine ECM also energizes solenoid valve (8). Solenoid valve (8) shifts. Pilot oil flows through solenoid