Takeuchi TB175W, Руководство по ремонту

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HYDRAULIC UNITS
SLEW MOTOR
IV-128
TB175W
The rebound pressure also pushes the check valve (1)
to the left, which is the opposite direction of pushing
at the time of braking. The flux control valve built in
the check valve (2) (that is now on the lower pressure
side) releases the oil in the damper chamber (4) at a
constant flux. Therefore, the check valve (1) moves at
a constant speed. When the check valve reaches its
stroke end, the passage from the port Pv2 to the port
Cv is closed.
Timer Valve
This function is used to prevent sudden operation of
the parking brake when the motor is stopped.
At the time of parking brake operation, pressure oil
from the port P4 is supplied at all times to the port PG,
the valve spool (1) is pushed to the right by the force
of the spring (2), and the port PG is closed.
When turning pilot pressure or arm pilot pressure is
led to the port SH, the spool (1) is moved to the left
against the force of the spring (2), and the port PG is
opened. The pressure oil from the port PG passes
through the hole at the center of the spool (1) and is led
to the parking brake release port (PB), so that the
parking brake is released.
When the pilot pressure at the port SH disappears, the
spool (1) is moved by the force of the spring (2) to the
right, the port PG is closed, and the oil in the brake
piston chamber (3) is prevented from escaping. The
oil in the chamber flows gradually through the orifice
(4) at the outer circumference of the spool (1) to the
drain port dr, so that the parking brake is not applied
rapidly, but after a certain time, just as if a timer were
used.
Parking Brake
The center discs (1) are connected to the housing and
the friction discs (2) are connected to the cylinder
block (3) via the spline, respectively. The center discs
(1) and friction discs (2) are pressed against the
housing (6) by the springs (4) via the brake piston (5).
The friction force between these discs generates the
brake torque to prevent the cylinder block (3) from
rotating.
When the pressure oil is introduced into the motor, the
oil flows from the parking brake release port (7) into
the brake piston chamber (8). The oil pressure over-
G4D606
Pv1 Cv Pv2
1 2
4
1 2 PG
PB
SH
L3D605
1 2
4
3
PG
L3D606
6
5
4
3
2
1
L3D607