Takeuchi TB175W, Руководство по ремонту

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HYDRAULIC UNITS
HYDRAULIC PUMP
IV-4
TB175W
OPERATION
Piston Pump
This pump is a variable displacement piston pump
with a single cylinder block, which discharges two
equal volumes.
Ten pistons (2) are installed in the cylinder block (1),
and the end surface is in contact with the valve plate
(3). The suction port C and the discharge port A of the
pump P1 and the discharge port B of the pump P2 are
arranged in the valve plate (3). On the other hand, the
swash plate (4) is fastened to the housing at a given
inclination, and the pistons (2) rotate along this swash
plate (4).
When the shaft (5) is rotated, the cylinder block (1)
rotates, the pistons (2) in the cylinder block execute
reciprocating movement along the swash plate (4),
and the pump executes suction and discharge. At this
time, the pistons in contact with the discharge port A
of the valve plate (3) operate as the pump P1, while the
pistons in contact with the discharge port B operate as
the pump P2.
In this way, the ten pistons (2) execute one suction and
discharge stroke with each revolution of the cylinder
block (1), so that suction and discharge are executed
continuously when the shaft (5) is rotated continu-
ously.
As the piston stroke displacement depends on the
inclination of the swash plate (4), the discharge flow
quantity can be changed by changing the inclination
of the awash plate (4).
Discharge volume control
The lever (1) can pivot on the pin and is linked with
the sleeve (2) and pin (3). The pin (3) is linked with the
swash plate (4) to change the inclination of the swash
plate.
The force exerted by the springs (7) and (8) acts on the
spool (6) while the average discharge pressure from
pumps P1 and P2 and discharge pressure from pump
P3 act on the piston (9). Also, the discharge pressure
selected by the shuttle valve (11) and transmitted
through the sleeve (2) and spool (6) acts on the servo
piston (10).
L3D101
3
1
2
4
5
L3D103
11 8
7
2
9
3
10
4
1
6 P2
P1
P3