5-6
3. STEERING VALVE
3. STEERING VALVE (EHPS ; Electro Hydraulic Power Steering)
STRUCTURE
STRUCTURE
The main spool in the steering valve (EHPS) can either be activated by the pilot unit or by the joy-
stick selected through the shuttle valves on each end of the main spool.
L
CL
CR
R
T
TS
LS EF
P
PS
1
6
2
3
4
5
7
8
9
10 11
12
13
14
Steering
valve
block
CF
EF
12bar
30bar
Pressure
reducing
valve
KV2
KV1
S3
Main spool
Shock valves
Suction valves
Hydraulic circuit
15
16
17
18
Controller
Joystick
CL
CR
L
EF
R
P
LS
T
Ps
Ts
ELECTRONICS
1 3
2 4
Joystick steering(opt)
Joystick steering(opt)
1)
1)
1 To
tank
2 To
emergency
system
3
To main control valve
4 From
main
pump
5
To steering unit P port
6
From steering unit T port
7
From steering unit L port
8
Shock & suction valve (left side)
9
To steering cylinder (left side)
10 To steering cylinder (right side)
11 Shock & suction valve (right side)
12 From steering unit R port
13 Relief
valve
14 Check
valve
15 Main
steering
spool
16 Pressure
reducing
valve
17 Metering
spool
18 Priority
spool
75795SE17
Summary of Contents for HL955
Page 557: ...7 6 MEMORANDUM MEMORANDUM ...