jcb 1CX, Руководство по обслуживанию

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Section E Hydraulics
9803/8550
Section E
Issue 1
4 - 2
General Description from machine no. 752463
The main components of the hydraulic circuit are the tank, pumps, drive motors, the servo operated loader and drive control
circuits, the manually operated excavator valves, filters, cooler, rams and solenoid brake valve.
The pumps are driven by the engine and are mounted in tandem. They deliver pressurised oil to the valves and motors. The
valves are operated by either a servo joystick in the case of the loader or drive circuits, or a manual control lever for the
excavator circuit. When a valve is operated, it delivers the oil to one end of the appropriate ram or to the pump servo-controls
depending on which control is operated. The pressurised oil forces the ram's piston along the bore of the ram or operates the
pump servo controls, which changes the flow direction to the motors and hence the direction of rotation. Relief valves prevent
system pressure from rising too far.
The Solenoid Brake Valve (together with its associated electrical circuitry) acts as a safety device. The safety function ensures
that the machine loader and transmission controls cannot be operated without the operator being seated correctly and the door
properly closed and latched.
Machine Neutral Circuit
(This description should be read in conjunction with the diagram below and the Hydraulic Schematic Diagrams starting on page
E/30 - 1)
Oil is drawn from the tank T by the auxiliary pump P3 via a suction strainer S1. The pump P3 delivers pressurised oil via non
return valve 3 to the loader control valve 2. Oil flows through the loader valve and onto the excavator valve 4 then via the filter
F1 to the main pumps P1 and P2. Oil from P1 and P2 is returned via the cooler C to the tank T. The oil feed for the servo
controls is taken from the main pump charge circuit via the solenoid brake valve 9.
The solenoid brake valve 9 acts as a safety device by preventing the oil supply to the loader and transmission servo controls
until the operator is seated correctly and the door properly closed and latched. The brake valve also allows the transmission
brakes to be manually applied.
4 - 2 Descriptions
2
3
T
P3
4
S1
F1
P2
P1
C
9
316840
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