Installation Instructions
7
STEERING
II
Right Turning
High Pressure
I=:::J
Low
Pressure
B177F705
1.
When the steering wheel
is
turned clockwise, the
worm shaft (3)
is
also turned. However,
front
wheel load stops sector gear shaft (1) and ball
nut
(2)
from moving, and only worm shaft (3) turns
clockwise.
Then due
to
the
reaction,
the
worm
shaft
(3)
moves downward a little. And
the
thrust
race
(8)
pushes
the
spool (7),
reaction
piston
(5) and
centering springs (4).
II
Manual Operation
(When Engine Stops
or
Hydraulic Circuit Troubles)
Even
when
the
engine stops or hydraulic circuit
malfunctions thus
leading
to
hydraulic
operation
stop,
manual
operation
is
possible.
However,
naturally, steering wheel requires a larger operating
power.
If
the steering
wheel
is
turned
when hydraulic
B1700·B2100·B2400
WSM,11770
(1
)
Sector Gear
Shaft
(2)
Ball
Nut
(3)
Worm
Shaft
(4)
Centering
Spring
(5)
Reaction Piston
(6)
Valve Housing
(7)
Spool
(8)
Thrust
Race
(9)
Ball
(10)
Relief Valve
(A)
Chamber
"A"
(B)
Chamber
"B"
(a)
Port"
a"
(b)
Port
"b"
7
2.
At
this time, the oil
passage
from pump
to
port
"a"
and oil
passage
from port
"b"
to
are closed.
Therefore, the pressure-fed oil from pump
flows
to
the chamber
"B"
through
port"b".
Thus,
the
ball
nut
(piston)
(2)
is
pushed, and
the
sector gear
shaft
(1)
is
rotated in the direction
ofthe
arrow.
circuit
ceases
to
operate, the worm shaft
(3)
moves
slightly
by
the stroke
of
spool (7),
then
the
worm
shaft
(3)
and ball
nut
(2)
have the
same
relationship
with
the
manual steering gear.
However,
the
steering wheel play increases
by
the
stroke
of
spool
(7).
7-M4