Chrysler laser 1990 Technical Information Manual page 216

POWER STEERING - Pinion and Valve Assembly Construction
OPERATION OF THE PINION AND VALVE
power cylinder is performed by the input shaft and
the rotary valve.
The concave and convex parts at the input shaft
surface and the rotary valve inner surface, due to
the rotational difference, function to either constrict
or expand the fluid passageway (by varying the
aperture surface area of the fluid passageway), and,
as a result, thereby regulating the hydraulic pressure
of the hydraulic circuit from the oil pump to the
cylinder tube left chamber or right chamber and
from the cylinder tube right chamber or left chamber
to the oil reservoir.
WHEN THE STEERING WHEEL IS TURNED TO
THE RIGHT
When the steering wheel is turned to the right, the
Port b
Port a
Port c
P o n d ' L
From
the left
cylinder
tube
Chamber "A"
II Y
Cylinder tube
Cylinder tube
right chamber
left chamber
torsion bar is. as shown in the illustration, caused to
torque in the direction of turning to the right, with
the result that the input shaft rotates by the
corresponding amount to the right, and a rotational
difference between the input shaft and rotary valve
develops. The concave and convex parts of the
input shaft and rotary valve cause oil passageways
for the fluid sent from the oil pump, the flow of fluid
is stopped from port "a" to port "d" and port "c".
When this happens, the fluid flows from the oil
pump to sleeve "a", port "a", port "b" and sleeve
thus causing the generation of a force to move the
rack in the leftward direction, thereby assisting the
steering effort of the steering wheel. At the same
time, the cylinder tube left chamber fluid flows
through sleeve "c", port "c", port "d" and chamber
"A", and is returned to the oil reservoir.
Torsion bar Port b
Oil
pump
Oil