Yanmar ViO12-2A, Руководство по обслуживанию

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6 . HYDRAULIC SYSTEM
6- 1- 2
1) Hydraulic Pump
The variable displacement piston pumps and the pilot
pump are linked to the flywheel of the engine through the
coupling. The number of revolutions of each hydraulic
pump is identical to the engine speed.
Discharge volume of each pump
2) Oil Flow
(when lock lever
s are
in the unlock position)
(1) Piston pumps P1 and P2
(when the lock levers are in the unlock position)
The pumps take in oil through the suction filter from the
hydraulic oil tank and discharge it. The discharged oil
flows to the ports P1 and P2 of the control valve and
returns from the port T to the hydraulic oil tank through
the return filter. This circulation is repeated.
The bypass valve in the return filter opens at a differen-
tial pressure of 0.147 MPa.
(2) Pilot pump P3
The oil from the pilot pump P3 flows back to the hydrau-
lic oil tank through the port A of the cut-off valve and the
pilot valves.
3) System Relief Valve
The system relief valves R1 and R2 of the control valve
control the discharge pressure of the pumps.
No. Pump
cm
3
/ rev
Discharge volume
P1
P2
1 Piston pump
2 Piston pump
3 Pilot pump P3
5.5
5.5
3 .0