FRAME AS-SUSP 5658443 - Caterpillar

Illustration 1 g01490215
Cross section of the straight travel control valve and the main relief valve (1) Main control valve (2) Return passage (3) Piston (4) Pilot passage (5) Parallel feeder passage (6) Right travel control valve (7) Left travel control valve (8) Main relief valve (9) Passage (10) Valve (11) Line (12) Line (13) Main pump (14) Pilot pump (15) Valve (16) ValveOil from main pump (13) enters main control valve (1) through line (11) . Main pump oil flows through main control valve (1) to main relief valve (8) , valve (10) , and parallel feeder passage (5) .When the circuit pressure in passage (9) is lower than the pressure setting of main relief valve (8) , valve (15) is closed and valve (16) is closed. The closed valves do not allow oil to flow from passage (9) to return passage (2) .
Illustration 2 g03370862
Main relief valve in the OPEN position during travel operation (2) Return passage (3) Piston (4) Pilot passage (9) Passage (15) Valve (16) Valve (17) Adjuster (18) Passage (19) Spring (20) Plug (21) Passage (22) Passage (23) Valve chamber (24) Spring (25) Spring chamberDuring travel operation, the pilot oil pressure from pilot passage (4) flows through passage (18) and the pilot oil pressure acts on the left end of piston (3) . Piston (3) shifts to the right and the piston compresses spring (19) to close valve (15) . Valve (15) is held in the closed position by force of spring (19) .The initial rise in oil pressure at passage (9) causes valve (16) to shift to the left against spring (24) . The oil pressure in passage (9) flows in two paths.Some oil pressure flows to return passage (2) and some oil pressure flows through passage (21) into spring chamber (25) . As oil pressure rises in spring chamber (25) , the oil pressure will begin to act upon the left side of valve (16) . Oil pressure will equalize on the left side and the right side of valve (16) . Then, spring (24) will shift valve (16) to the right. Oil pressure in spring chamber (25) raises against valve (15) . The force that is required for valve (15) to overcome spring (19) is higher during a travel operation. Spring (19) maintains the pressure setting of main relief valve (8) .As the oil pressure in passage (9) increases to the relief pressure setting for the travel circuit, the oil pressure in passage (9) overcomes the force of spring (19) and the oil pressure shifts valve (15) to the left. The oil in spring chamber (25) flows to valve chamber (23) . The oil in valve chamber (23) now flows through passage (22) to return passage (2) and the oil becomes low pressure.
Illustration 3 g03370864
Main relief valve in the OPEN position during implement operation or during swing operation (2) Return passage (3) Piston (4) Pilot passage (9) Passage (15) Valve (16) Valve (19) Spring (21) Passage (22) Passage (23) Valve chamber (24) Spring (35)