Takeuchi TB53FR, Руководство по ремонту

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HYDRAULIC UNITS
TRAVEL MOTOR
IV-101
TB53FR
C4D557
3 6 2 1 5 4
C4D558
2 1 5 4 7 8
E5D512
6
9
C
5
3
10
11
A
7
B
8
β
α
Swash Plate
The swash plate (5) has 3 planes, A, B and C, as shown
in the figure, and it is assembled in such a way that its
angle of inclination in the flange holder (6) can varied
by two balls (7). When the 2-speed control valve is
switched to the 1st speed side, the swash plate control
piston chamber is connected to tank port and the
swash plate (5) is stabilized at plane A, forming swash
plate angle a, by the piston assembly (8) and the force
of the springs (9), (10), achieving 1st speed (low
speed) motor rotation.
When the 2-speed control valve is switched to 2nd
speed, the swash plate control piston chamber (3) is
connected to the motor drive pressure port and the
swash plate (5) stabilizes at plane B due to the equi-
librium between the force of the springs (9), (10) and
the force of the control piston (11), thus, assuming
swash plate angle ß. In this way, 2nd speed (high
speed) motor rotation is achieved.
When the engine is stopped, the pilot pressure of the
2-speed control valve is cut off, so the swash plate (5)
is stabilized at the swash plate a plane A by the force
of the springs (9), (10), changing to the 1st speed side.
For this reason, when starting, the motor also is in 1st
speed.
Parking brake
The center discs (1) are connected to the flange holder
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 flange
holder (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
spool of the counterbalance valve moves and the oil
flows from the parking brake release port (7) into the
brake piston chamber (8). The oil pressure overpow-
ers the spring force and moves the brake piston (5) to
the right. This generates a clearance between the
center discs (1) and friction discs (2) to release the
parking brake. When the motor stops, the spool re-
turns to the neutral position to close the parking brake
release port (7). The pressure oil in the brake piston
chamber (8) is introduced into the motor case and the
spring (4) operates the parking brake.