CARRIER-PLANETARY 2379067 - Caterpillar

Illustration 4 g01991414
(1) Port (7) Passage (8) Chamber (9) Pressure compensator valve (13) Spool (14) Spring (18) Passage (19) Passage (20) Passage (21) Passage (22) Chamber
Illustration 5 g01438875
(C) Boom RAISE (E) HOLDWhen the boom circuit is the only hydraulic circuit in operation, the boom circuit will have the highest signal oil pressure in the hydraulic system. When the joystick on the right side is moved to position (C), the control valve is in the boom RAISE position. Pilot oil enters the control valve through port (25) and flows to port (1). When the pilot oil overcomes the force of spring (14), spool (13) moves to the right.When the spool (13) moves to the right, pump supply oil flows from passage (19) around the spool (13) and into passage (20) .The hydraulic oil in passage (20) flows to pressure compensator valve (9). In the pressure compensator valve (9), the hydraulic oil flows into internal passages. The pressure compensator valve (9) moves up. As the pressure compensator valve (9) moves up, the cross-drilled passage is opened to an internal passage that is in the valve. Some of the hydraulic oil flows around the pressure compensator valve (9) to chamber (7) and chamber (8). The hydraulic oil that flows to chamber (8) is signal oil. The signal oil balances the pressure compensator valve (9) against the hydraulic oil pressure in passage (20). This controls the flow across spool (13) .The signal oil in the internal passage flows to the pressure compensator valve (9) in each control valve. The signal oil also flows to the pressure and flow compensator valve on the hydraulic pump. The signal oil helps to control the output of the hydraulic pump. The hydraulic pump upstrokes and the hydraulic oil pressure increases in passage (19) and in passage (20). When the hydraulic oil pressure raises above circuit pressure in passage (20) and chamber (7) the pressure unseats check valve (10). The hydraulic oil flows to passage (18) and passage (21) .In passage (18), spool (13) blocks the flow of oil. In passage (21), the oil flows around the spool (13) to chamber (22).
Illustration 6 g01438890
(4) Lower section of the poppet (5) Port (22) Chamber (26) Spring (27) Spring (28) Ball (29) Chamber (30) Upper section of the poppetWhen the oil pressure overcomes the force of spring (26) and spring (27), the lower section (4) of the poppet moves upward. Oil flows through the lower section (4) of the poppet into chamber (29). The oil flows through section (30) of the poppet. The oil then flows through the port (5). As the flow of oil increases, the ball (28) moves up. Spring (27) is compressed more. Oil flows around the ball (28) into chamber (29). This oil helps balance the pressure in chamber (29) and chamber (22) .The oil that flows through port (5) flows to the rod end of the boom cylinder. This raises the boom.Hydraulic oil from the head end of the boom cylinder flows through port (11) to passage