Komatsu ecot3 PC300LC-8 Shop Manual page 141

10 Structure, function and maintenance standard
Basic principle
1. Pump swash plate angle control
q The pump swash plate angle (pump delivery)
is controlled so that LS differential pressure
E
( PLS) (the difference between pump pres-
sure PP and control valve outlet port LS pres-
sure PLS) (load pressure of actuator) is
constant.
[LS differential pressure (
q
charge pressure (PP) – LS pressure (PLS)]
PC300, 350-8
E
PLS) = Pump dis-
q The pump swash plate angle shifts toward the
maximum position if LS differential pressure
E
( PLS) is lower than the set pressure of the
LS valve (when the actuator load pressure is
high).
q If it becomes higher than the set pressure
(when the actuator load pressure is low), the
pump swash plate angle shifts toward the mini-
mum position.
LS differential pressure (
swash plate angle
a For details of functions, see the "Hydraulic
pump" paragraph.
SEN01994-01
E
PLS) and pump
15