STRUCTURE OF MAIN PUMP LS VALVE
Sectional view
PA: Pump port
PDP: Drain port
PLP: LS control pressure output port
PLS: LS pressure input port
PP: Pump port
PPL: Control pressure input port
PSIG: LS mode selector pilot port
1: Sleeve
2: Piston
3: Spool
4: Spring
5: Seat
6: Sleeve
7: Plug
8: Lock nut
FUNCTION OF MAIN PUMP LS VALVE
• The LS (load sensing) valve detects the load of the actuator and controls the pump discharged volume.
• This valve controls pump discharged volume (Q) according to differential pressure (∆PLS) = “(PP) - (PLS)”
(called LS differential pressure) between pump discharged pressure (PP) and control valve outlet port pres-
sure (PLS).
• This valve receives main pump pressure (PP), pressure (PLS) (called LS pressure) from the control valve
output, and pressure (PSIG) (called LS set selector pressure) from the proportional solenoid valve.
• The relationship between differential pressure (∆PLS) =
“(PP) - (PLS)”, the difference between main pump pres-
sure (PP) and LS pressure (PLS), and discharged volume
(Q) varies with LS set pressure selector current (ISIG) of
LS-EPC valve as shown in the figure.
• When (ISIG) varies from 0A to 1A, the set pressure of the
spring changes, and the selector point for pump dis-
charged volume changes as shown in the figure below.
10 STRUCTURE AND FUNCTION
COMPONENT PARTS OF HYDRAULIC SYSTEM
PC500LC-10R
10-115
Summary of Contents for PC500LC-10R
Page 1: ...HYDRAULIC EXCAVATOR SEN06722 00 PC500LC 10R SERIAL NUMBERS 100001 and up...
Page 2: ......
Page 3: ...00 INDEX AND FOREWORD PC500LC 10R 00 1...
Page 76: ......
Page 77: ...01 SPECIFICATIONS PC500LC 10R 01 1...
Page 94: ......
Page 95: ...10 STRUCTURE AND FUNCTION PC500LC 10R 10 1...
Page 177: ...When balanced 10 STRUCTURE AND FUNCTION CLSS PC500LC 10R 10 83...
Page 178: ...When lever is returned to fine control state CLSS 10 STRUCTURE AND FUNCTION 10 84 PC500LC 10R...
Page 179: ...When lever is pulled at a stroke 10 STRUCTURE AND FUNCTION CLSS PC500LC 10R 10 85...
Page 180: ...When lever is in stroke end CLSS 10 STRUCTURE AND FUNCTION 10 86 PC500LC 10R...
Page 377: ...20 STANDARD VALUE TABLE PC500LC 10R 20 1...
Page 407: ...30 TESTING AND ADJUSTING PC500LC 10R 30 1...
Page 583: ...30 TESTING AND ADJUSTING METHOD FOR STARTING UP KOMTRAX TERMINAL PC500LC 10R 30 177...
Page 604: ......
Page 605: ...60 MAINTENANCE STANDARD PC500LC 10R 60 1...
Page 636: ...MAINTENANCE STANDARD OF MAIN PUMP 60 MAINTENANCE STANDARD 60 32 PC500LC 10R...
Page 638: ...MAINTENANCE STANDARD OF SWING MOTOR 60 MAINTENANCE STANDARD 60 34 PC500LC 10R...
Page 641: ...60 MAINTENANCE STANDARD MAINTENANCE STANDARD OF TRAVEL MOTOR PC500LC 10R 60 37...
Page 644: ...MAINTENANCE STANDARD OF CONTROL VALVE 60 MAINTENANCE STANDARD 60 40 PC500LC 10R...
Page 646: ...MAINTENANCE STANDARD OF CONTROL VALVE 60 MAINTENANCE STANDARD 60 42 PC500LC 10R...
Page 648: ...MAINTENANCE STANDARD OF CONTROL VALVE 60 MAINTENANCE STANDARD 60 44 PC500LC 10R...
Page 650: ...MAINTENANCE STANDARD OF CONTROL VALVE 60 MAINTENANCE STANDARD 60 46 PC500LC 10R...
Page 652: ...MAINTENANCE STANDARD OF CONTROL VALVE 60 MAINTENANCE STANDARD 60 48 PC500LC 10R...
Page 658: ...MAINTENANCE STANDARD OF TRAVEL PPC VALVE 60 MAINTENANCE STANDARD 60 54 PC500LC 10R...
Page 668: ...MAINTENANCE STANDARD OF WORK EQUIPMENT LINKAGE 60 MAINTENANCE STANDARD 60 64 PC500LC 10R...
Page 679: ...90 CIRCUIT DIAGRAMS PC500LC 10R 90 1...
Page 692: ......
Page 694: ......
Page 696: ......
Page 698: ......
Page 700: ......
Page 704: ...Symbol Content Buzzer Antenna SYMBOLS USED IN ELECTRICAL CIRCUIT DIAGRAM 90 26 PC500LC 10R...
Page 706: ......
Page 708: ......
Page 710: ......
Page 712: ......
Page 714: ......
Page 716: ......
Page 718: ......
Page 720: ......
Page 722: ......
Page 724: ......
Page 726: ......
Page 728: ......
Page 730: ......
Page 732: ......
Page 734: ......
Page 736: ......
Page 738: ......
Page 740: ......
Page 742: ......
Page 744: ......
Page 746: ......
Page 748: ......
Page 757: ......