ELBOW 0311381 - Caterpillar

Illustration 1 g01091411
Bowl Circuit in LOWER Position (1) Sequence and pressure control valve (2) Common oil line (3) Snubber (4) Pressure switch (5) Actuator for the bowl (6) Actuator for the apron (7) Actuator for the ejector (9) Valve spool for the apron (8) Valve spool for the ejector (10) Valve spool for the bowl (11) Actuator for the ejector (12) Actuator for the apron (13) Actuator for the bowl (14) Main control valve (15) Apron cylinder (16) Main relief valve (17) Pilot oil supply line (18) Vent line from carry-check valve (19) Vent line from quick-drop (20) Shuttle valve (21) Screen (22) Pilot oil filter (23) Solenoid and pressure reducing valve (24) Oil line from the main control valve to the carry-check and quick-drop valve (25) Quick-drop valve (two) (26) Check valve (two) (27) Line from main control valve to the tank (28) Carry-check and quick-drop valves (29) Carry-check valve (two) (30) Oil line from the carry-check and quick-drop valve to the rod end of the cylinder (31) Line from cushion-hitch pump (32) Line to cushion-hitch valve (33) Bowl cylinder (two) (34) Line for equalization of bowl cylinders (35) Line to steering system (36) Ball valve (37) Oil filter (38) Hydraulic tank (39) Gear pump (hydraulic and steering) (40) Cushion-hitch pump (41) Case drain screen for the cushion-hitch pump (42) Ejector valve (speed change) (43) Ejector cylinder (44) Piston (45) Oil line to the rod end of the apron cylinder (46) Check valve (47) Relief valve (48) Oil line to the sequence and pressure reducing valve (49) Line to head end of the apron cylinder (50) Oil line from the ejector valve (speed change) to the rod end of the cylinder (51) Oil line from the ejector valve (speed change) to the head end of the cylinder (52) Oil line from the control valve to the ejector valve (speed change) (AA) Pressure oil from pump (BB) Pilot oil (CC) Return oil (DD) Blocked oilImplement pilot circuit
Illustration 2 g00760418
Joystick ControlWhen the engine is started with the joystick control in the HOLD position, the cushion-hitch pump (40) sends oil through line (31). Some of the oil flows through line (32) to the cushion-hitch valve. The rest of the oil flows through shuttle valve (20) and through screen (21) to solenoid and pressure reducing valve (23). Oil flows through solenoid and pressure reducing valve (23) to filter (22). Oil from the solenoid and pressure reducing valve then flows to main control valve (14). Regardless of the joystick movement, the oil supply from the solenoid and pressure reducing valve is the pilot supply oil to the actuators for the following implements: the bowl, the apron and the ejector.Lowering the Bowl
When joystick control is moved to LOWER position, an electrical current is sent to the solenoid in actuator (13). Then, valve spool (10) shifts in order to lower the bowl. Pump oil flows around valve spool (10) and through line (2). Then, oil flows into the carry-check and quick-drop valves (28) and into