Sakai SW800 Series, Руководство по ремонту

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2-027
Description and Operation of Hydraulic System
Circuit protection against high pres-
sure:
• Cut off valve (e) is fitted in the propulsion
pump. If the circuit pressure exceeds the
setting of the valve, the valve functions and
exerts oil pressure on the pump servo piston
to reduce pump delivery.
• Decrease in delivery (travel speed reduc-
tion) lowers the circuit pressure.
• In addition to this cut off valve, the circuit
includes high pressure relief valve (c) which
opens to protect the circuit if the circuit pres-
sure exceeds the permissible maximum of
the cut off valve.
Charge circuit:
• The propulsion circuit is of a closed circuit,
which needs feeding of oil into it for making
up for deficiency and for other purposes.
• In the charge circuit, oil from steering pump
(13) flows into Orbitrol (14), then the whole
amount of oil goes to propulsion pump (3)
via filter (15) irrespective of the steering
wheel operation.
• The pressure adjustment is achieved by
charge relief valve (d) built in the propulsion
pump when the F-R lever is in the neutral
position. When travelling, the pressure is
adjusted by flushing valve (g) built in rear
propulsion motor (7).
Oil that flows through the charge circuit
plays other roles. Those are renewing and
cooling of oil and removal of foreign matter.
FRONT ROLL
REAR ROLL
IN
OUT
T2
A
B A
B A
DR
B
A
PB
DR
B
T
P
OUT
IN
T
P
P.T.O
S
D
PB
8
7
10
9
f
g
e
d
c
c
3
15
14
13
12
SW8002018