![]() | |
Illustration 1 | g00873428 |
Pilot System (1) Pilot manifold (2) Pilot relief valve (low pressure circuit) (3) Pilot system accumulator (4) Solenoid valve (dual pressure) (5) Solenoid valve (swing parking brake) (6) Solenoid valve (bucket bottom dump open) (7) Solenoid valve (bucket bottom bump close) (8) Solenoid valve (travel parking brake) (9) Travel parking brakes (10) Swing parking brakes (11) Machine control module (12) Vital Information Management System (VIMS) (13) Engine Control Module (ECM) (14) Pilot relief valve (high pressure circuit) (15) Swing control valve (16) Solenoid valve (boom float)(front shovel only) (17) Load sensing signal relief valve (18) Front control valve (19) Boom float relay (20) Proportional reducing valve (power shift pressure) (21) Solenoid valve (engine cooling fan motor) (22) Solenoid valve (hydraulic cooling fan motor) (23) Control manifold (24) Flow (pilot oil to the swing pump regulator) (25) Pressure sensor (swing)(normally closed switch) (26) Flow (pilot oil to the control valve spools) (27) Relief valve (swing dual pressure) (28) Pressure switch (implement)(normally closed switch) (29) Pressure switch (travel and bucket bottom dump)(normally open switch) (30) Rear control valve (31) Solenoid valve (warm-up) (32) Swivel (33) Hydraulic activation control valve (34) Pilot hydraulic oil filter (35) Automatic track tension system (left) (36) Automatic track tension system (right) (37) Flow (pilot oil to the pilot valve spools) (38) Motor (drive for the air conditioning compressor) (39) Relief valve (air conditioning circuit) (40) Gear pump (air conditioning section) (41) Gear pump (pilot section) |
The pilot hydraulic system provides pilot oil to the following circuits: implement control circuit, swing control circuit and travel control circuit. The pilot oil in these control circuits physically moves the spools in the main control valves in order to initiate the desired function. The pilot hydraulic system provides pilot oil to the automatic track tensioning system and the power shift system.
Pilot gear pump section (41) is mounted on the output shaft of the radiator cooling fan pump. Pilot gear pump section (41) supplies the pilot system with oil. Pilot gear pump section (41) is located at the rear of the center stack of three pumps.
The output oil from pilot gear pump section (41) passes through pilot hydraulic oil filter (34). Pilot hydraulic oil filter (34) is mounted near pilot gear pump section (41). From the pilot hydraulic oil filter, the pilot oil splits into following three circuits:
- One circuit supplies continuous high pressure pilot oil to the automatic track tensioning system in each track roller frame.
- The second circuit supplies low pressure pilot oil to the machine's pilot control system.
- The third circuit supplies continuous high pressure pilot oil to the control manifold valve that is located in the pump compartment. A second pump section supplies oil from air conditioning gear pump section (40) to motor (38) that drives the air conditioning compressor.