Hyundai HX130LCR Manual page 62

(3)
Power shift control
621 652
Large diameter
chamber
The set horsepower valve is shifted by
varying the command current level of
the proportional pressure reducing
valve attached to the pump.
Only one proportional pressure redu-
cing valve is provided.
However, the secondary pressure Pf
(power shift pressure) is admitted to the
horsepower control section of each
pump regulator through the pump's
internal path to shift it to the same set
horsepower level.
This function permits arbitrary setting of the pump output power, thereby providing the optimum
power level according to the operating condition.
The power shift pressure Pf controls the set horsepower of the pump to a desired level, as
shown in the figure.
As the power shift pressure Pf rises, the compensating rod (623) moves to the right via the pin
(898) and compensating piston (621).
This decreases the pump tilting angle and then the set horsepower in the same way as
explained in the overload preventive function of the horsepower control. On the contrary, the
set horsepower rises as the power shift pressure Pf falls.
651 623 612 601
P1 CL
F
P2 P1
D
Servo piston
2-18
625 626
B(E)
897
875
611
Small diameter
chamber
Delivery pressure, (P
140Z92RG05
+P )
1 2