GEAR-COUPLING 1193379 - Caterpillar

Illustration 1 g03799657
Medium Pressure (partial schematic)
(1) Oil cooler
(2) Motor for rotation
(3) Line relief valves
(4) Auxiliary control valve
(6) Proportional reducing valve (Extend)
(7) Proportional reducing valve (Retract)
(8) Main control valve
(9) Pilot manifold
(10) Solenoid valve for hydraulic lock
(11) Pilot pump
(12) Rear pump
(13) Front pump
(14) Load pressure sensor
(15) Hydraulic tank Medium pressure is designed to provide oil to the work tool for tool rotation. Attachment control valve (4) is used to control the oil flow. This valve is shifted with proportional reducing valves (6) and (7) that allows the operator complete electronic control over the tool rotation. Front pump (13) is used to supply oil flow for medium pressure. Load pressure sensor (14) is used to control oil pressure in the medium pressure circuit. If the pressure reaches the set pressure or higher, the machine ECM will send the appropriate signals to proportional reducing valves (6) and (7) that controls the attachment control valve (4) to reduce the pilot pressure. A typical example of a work tool that will use medium pressure is a shear.Reference: Refer to Testing and Adjusting, "Work Tool Parameter - Program" for the tool control system to change the settings for work tool operation.Reference: Refer to Testing and Adjusting, "Medium Pressure: Default Value of Work Tool Parameters" for the Tool Control System to reference the factory settings.
Table 1
Operation Lever List
Control Extension Retraction
Left Joystick Thumb Wheel Push Forward Push Backward
Electric Foot Pedal Push Forward Push Backward Attachment Valve Retracted
Illustration 2 g03799658
Attachment valve retracted (partial schematic)
(2) Motor for rotation
(3) Line relief valves
(4) Auxiliary control valve
(7) Proportional reducing valve (retract)
(11) Pilot pump
(12) Rear pump
(13) Front pump
(14) Load pressure sensor
(15) Hydraulic tank When the device for activation is operated in the extend position, proportional reducing valve (7) receives a modulated signal from the machine ECM. Proportional reducing valve (7) allows pilot oil to flow to attachment control valve (4). The pilot oil shifts attachment control valve (4) allowing medium pressure oil from front pump (13) to flow to hydraulic rotator motor (2).Oil returning from the rotator motor flows through attachment control valve (4), oil cooler (1), and to hydraulic tank (15).The working pressure for rotation is limited by load pressure sensor (14).Attachment Valve Extended
Illustration 3 g03799659
Attachment valve extended (partial schematic)
(2) Motor for rotation
(3) Line relief valves
(4) Auxiliary control valve
(6) Proportional reducing valve (extend)
(11) Pilot pump
(12) Rear pump
(13) Front pump
(14) Load pressure sensor
(15) Hydraulic tank When the device for activation is operated in the retract position, proportional reducing valve (6) receives a modulated signal from the machine ECM. Proportional reducing valve (6) allows pilot oil to flow to attachment control valve (4). This shifts attachment control valve (4) allowing medium pressure oil from the front pump (13) to hydraulic rotator motor (2).Oil returning from the rotator motor flows through attachment control valve (4), oil cooler (1), and back to hydraulic tank (15).The working pressure for rotation is limited by load pressure sensor (14).