1990 MITSUBISHI ECLIPSE wheel torque

POWER STEERING- Pinion and Valve Assembly Construction19-9
WHEN THE STEERING WHEEL IS TURNED TO
THE LEFT
JVhen the steering wheel is turned to the left, the
torsion bar is, as shown in the illustration, caused to
torque in the direction of turning to the left, with the
result that the input shaft rotates by the correspond-
ing amount to the left, and a rotational difference
between the input shaft and rotary valve develops.
The concave and convex parts of the input shaft androtary valve cause oil passageways L’ and
R to
become constricted, with the result that, for the
fluid sent from the oil pump, the flow of fluid is
stopped from port “a” to port “d” and port
“b”.
IPort dnber
*oil pump
VTo the left
cylinder tube13LOO73
SleeveWhen this happens, the fluid flows from the oil
pump to sleeve “a”,port “a”, port “c” and sleeve
“c” and is sent to the cylinder tube left chamber,
thus causing the generation of a force to move the
rack in the rightward direction, thereby assisting the
steering effort of the steering wheel.
At the same time, the cylinder tube right chamber
fluid flows through sleeve “b”, port “b”, port “d”
and chamber “A”,
and is returned to the oil
reservoir.Oil pump
Oil reservoir
Sleeve
cCylinder tube
left chamberCylinder tube
right chamber
‘Y R

21-10MANUAL TRANSAXLE <4WD> - General Information4WD SYSTEM OPERATION
Conventional 4WD systems (direct-coupled
4WD,or center differential type 4WDl have their own
merits and demerits; they rely on manual operation
(switching between 4WD and 2WD modes, center
differential locking) to cope with their demerits.
With this new 4WD system, the viscous coupling
built in the center differential automatically performssuch operations used to be made manually. The
driver can participate with the merits of 4WD at alltimes.The operation of the differential and the
viscous
coupling under representative conditions
are described in the following section.
I
Reardifferential
Center
differential
U differential
Viscous AuDk?TFNOO5’difference
ce271010i
TFMMYTFMMY
0
Turningdirection
ITFMOO!X
-.During normal driving
During normal driving (traveling straight on a level road at a
constant speed), the four wheels rotate at nearly the same
speed. Since there is no rotating speed difference among the
four wheels, the viscous coupling does not apply differential
limiting torque and the three differentials distribute drive power
equally to all of the wheels.
During a sharp turn
During a sharp turn, in addition to the rotating speed difference
between the left and right wheels, a small difference in rotati
speeds between the front and rear wheels also occurs.
Such rotational speed difference is absorbed by the differential
action of the three differentials, thereby allowing smooth
driving.The rotational speed difference is also transmitted to the
viscous coupling but the difference is so small that the coupling
makes almost no differential limiting torque application conse-
quently it does not affect the differential action of the center
differential.
When starting out and accelerating
When starting out and accelerating, the center of gravity of the
vehicle shifts towards the rear increasing the rear wheel load
and decreasing the front wheel load. The center
differenti”causes less drive power to be transmitted to the rear whee.
resulting in a lower driving torque. At the same time, however,
the rotational speed difference between the front and rear
wheels increases and the viscous coupling operates to limit the
differential action of the center differential. securing a supply of
drive power to the rear wheels. In this way, performance when
starting out and accelerating is secured.

MANUAL TRANSAXLE <4WD> - General Information21-I 1When driving on rough roads. . .In case either a front or rear wheel starts spinning on a slippery
or muddy road or when the vehicle is stuck in mud and one tire
spins, the drive power will be decreased by differential action.
However, as this also causes a sharp increase of speed
difference of the viscous coupling, a large differential limiting
torque is now applied, with more power transmitted to the tires
that are not spinning so that the vehicle can drive through or
getout of mud.A