Sakai SW800 Series, Руководство по ремонту

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2-026
Description and Operation of Hydraulic System
Operation (It is assumed that the
machine travels forward.)
★
The negative brake (spring-applied
hydraulically released brake) is sup-
posed to have been released.
♦
Assemblies such as pump ass’y and motor
ass’y are indicated by numbers such as ‘1’
and ‘2’, while component parts of assemblies
are shown by small letters such as ‘a’ and ‘b’.
♦
The circuit of the front motor and that of the
rear motor connect in parallel with each other.
• When the forward-reverse lever (F-R
lever) is moved forward, control valve (a)
functions to tilt the pump swashplate in the
forward travel direction.
• Propulsion pump (3) discharges oil from
its port B into the forward travel circuit,
then the oil flow is divided into two lines;
the forward travel line connecting to port A
of front motor (8) and that connecting to
port B of rear motor (7).
• The oil fed into the forward travel ports of
the motors drives the motors, flowing out
from the opposite side ports. Two flows of
oil from the motors meet with each other
and get into port A of pump (3). At the
same time, part of oil in the rear motor is
dumped into the tank through shuttle valve
(f) and flushing valve (g) both of which are
built in motor (7), and also through the
motor casings.
• Power from the motors is delivered to drums
(9) and (10) through gear reducers (i).
♦ Front motor (10) is not equipped with
shuttle valve (f) and low pressure relief
valve (g).
NOTE: Because the propulsion circuit is a
closed loop circuit, the suction and
discharging fuctions are reversed
with each other when the travel
direction is reversed. (The direction
of oil flow is reversed.)
Disengaging the negative brake:
• When energized, brake release solenoid
(11) functions to deliver oil, through it, from
the charge circuit to the brake release ports
in the propulsion motor.
• The oil then pushes the brake piston in each
negative brake (h), disengaging the brake.
IN
OUT
T2
A
B A
B A
DR
B
A
PB
DR
B T
P
PB
h h
8
7
3
10
9
i
i
f
g
11
e
d
c
b
a
SW8002017
c
To Orbitrol