10-34
WB97S-5
STRUCTURE AND FUNCTION
HYDRAULIC PUMP
LS VALVE FUNCTION
•
The LS valve controls the pump delivery according
to the stroke of the control valve lever, i.e., in
function of the delivery demands made by the
actuators.
•
The LS valve detects the actuator’s delivery
needs by means of the differential pressure
DPLS existing between pressure PPLS (control
valve input pressure) and pressure PLS (control
valve output pressure). The sensing of this
differential pressure permits control of the main
pump delivery
Q
. (PPLS, PLS and DPLS are,
respectively, the pump pressure, the Load
Sensing pressure, and the difference in pressure
between these two values).
•
In other words, the LS valve detects the pressure
difference DPLS generated by the passage of
the oil flow through the surface freed by the
control valve spool, and controls the pump
delivery
Q
so as to keep the pressure drop
constant.
It can therefore be assumed that the pump
delivery is proportional to the demands made
known by the control valve.
•
Pump pressure PPLS (pump pressure at control
valve input) and pressure PLS (Load Sensing
pressure) are introduced into the LS valve. The
relation between differential pressure DPLS and
pump delivery varies as shown in the diagram on
the right.
RKZ09570
bar
LS differential pressure dPLS
Pump
deliver
y
Q
Summary of Contents for WB97S-5
Page 1: ...WEBM007500 WB97S 5 BACKHOE LOADER SERIAL NUMBER F00003 and up WB97S 5 SHOP MANUAL ...
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Page 161: ...TESTING AND ADJUSTMENTS WB97S 5 20 17 NORMAL OR STANDARD TECHNICAL DATA Fig S RKZ10830 ...
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Page 581: ...40 15 WB97S 5 STANDARD MAINTENANCE CONTROL VALVE RKZ09071 C C B B A A AE AE X View X ...
Page 589: ...40 23 WB97S 5 STANDARD MAINTENANCE CONTROL VALVE ViewX RKZ09591 C C B B A A AE AE ...
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Page 611: ...90 1 WB97S 5 90 OTHER ELECTRICAL DIAGRAM STANDARD VERSION 3 ...
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Page 616: ... 2006 KOMATSU UTILITY EUROPE S p A All Rights Reserved Printed in Europe 06 2006 ...