Hyundai R 160 LC-3, Service Manual

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2-45
2. FUNCTION
ROTARY PART
When high pressurized oil enters a cylinder through port(a), which is the inlet of balance plate(131),
hydraulic pressure acting on the piston causes axial force F. The pressure force F works via the
piston(121) upon the return plate(123) which acts upon the swash plate(124) via an hydrostatic
bearing. Force F1 perpendicular to swash plate(124) and force F2 perpendicular to cylinder center.
Being transferred to the cylinder block(111) through piston, force F2 causes rotational moment at
surroundings of cylinder.
Since cylinder block has 9 equidistantly arrayed pistons, rotational torque is transmitted to cylinder
shaft in order by several pistons connected to the inlet port of high pressurized oil. When the
direction of oil flow is reversed, rotational direction of cylinder is also reversed. Output torque is
given by the equation.
p
ź
q F
T = , q = Z
ş
A
ş
PCD
ş
tan
ҋ
, F
1
= , F
2
=F tan
ҋ
, S=PCD
ź
tan
ҋ
2 ० COS ҋ
Where p : Effective difference of pressure(kgf/cm 2 )
q : Displacement(cc/rev)
T : Output torque(kgf ş cm)
Z : Piston number(9EA)
A : Piston area(cm 2 )
ҋ
: Tilting angle of swash plate(degree)
S : Piston stroke(cm)
Low
pressure oil
F1
F
F2
124 123 121 111
131
High
pressure oil
1)