SECTION 5 - HYDRAULICS
3121259
– JLG Lift –
5-37
Electrical Displacement Control (EDC)
EDC PRINCIPLE
The Electrical Displacement Control (EDC) consists of propor-
tional solenoids on each side of a three-position, four-way
porting spool. The proportional solenoid applies a force to the
spool, which ports hydraulic fluid to either side of the servo
piston. Differential pressure across the servo piston rotates the
swashplate, changing the pump's displacement from full dis-
placement in one direction to full displacement in the oppo-
site direction.
EDC OPERATION
H1 EDC's are current driven controls requiring a Pulse Width
Modulated (PWM) signal. Pulse width modulation allows more
precise control of current to the solenoids. The PWM signal
causes the solenoid pin to push against the porting spool,
which pressurizes one end of the servo piston, while draining
the other. Pressure differential across the servo piston moves
the swashplate. A swashplate feedback link, opposing control
links, and a linear spring provide swashplate position force
feedback to the solenoid. The control system reaches equilib-
rium when the position of the swashplate spring feedback
force exactly balances the input command solenoid force from
the operator. As hydraulic pressures in the operating loop
change with load, the control assembly and servo/swashplate
system work constantly to maintain the commanded position
of the swashplate.
The EDC incorporates a positive neutral dead-band as a result
of the control spool porting, spring preload from the servo pis-
ton assembly, and the linear control spring. Once the neutral
threshold current is reached, the swashplate position becomes
directly proportional to the control current.To minimize the
effect of the control neutral deadband, we recommended the
transmission controller or operator input device incorporate a
jump up current.
NOTE:
The neutral position of the control spool does provide a
positive preload pressure to each end of the servo piston
assembly.
Содержание 340AJ
Страница 1: ...Service and Maintenance Manual Model 340AJ P N 3121259 June 27 2017...
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Страница 10: ...vi JLG Lift 3121259 TABLE OF CONTENTS SECTION NO TITLE PAGE NO Thispageleftblankintentionally...
Страница 15: ...3121259 JLG Lift xi LIST OF FIGURES FIGURE NO TITLE PAGE NO Thispageleftblankintentionally...
Страница 18: ...xiv JLG Lift 3121259 LIST OF TABLES TABLE NO TITLE PAGE NO Thispageleftblankintentionally...
Страница 42: ...SECTION 2 GENERAL 2 12 JLG Lift 3121259 NOTES...
Страница 69: ...SECTION 3 CHASSIS TURNTABLE 3121259 JLG Lift 3 27 Figure 3 24 Bearing Pressing Tool...
Страница 71: ...SECTION 3 CHASSIS TURNTABLE 3121259 JLG Lift 3 29 Figure 3 27 Bearing Nut Wrench...
Страница 134: ...SECTION 3 CHASSIS TURNTABLE 3 92 JLG Lift 3121259 NOTES...
Страница 157: ...SECTION 4 BOOM PLATFORM 3121259 JLG Lift 4 23 Figure 4 8 Rotator Counterbalance Valve...
Страница 218: ...SECTION 5 HYDRAULICS 5 58 JLG Lift 3121259 Figure 5 32 Fasteners and Plugs Sheet 1 of 2...
Страница 219: ...SECTION 5 HYDRAULICS 3121259 JLG Lift 5 59 Figure 5 33 Fasteners and Plugs Sheet 2 of 2...
Страница 236: ...SECTION 5 HYDRAULICS 5 76 JLG Lift 3121259 Figure 5 39 Gear Pump Cutaway...
Страница 246: ...SECTION 5 HYDRAULICS 5 86 JLG Lift 3121259 Figure 5 40 Oil Sampling Port...
Страница 255: ...SECTION 6 JLG CONTROL SYSTEM 3121259 JLG Lift 6 9 PLATFORM MODULE GROUND MODULE Figure 6 2 Control Module Location...
Страница 256: ...SECTION 6 JLG CONTROL SYSTEM 6 10 JLG Lift 3121259 Figure 6 3 Ground Module Sheet 1 of 4...
Страница 267: ...SECTION 6 JLG CONTROL SYSTEM 3121259 JLG Lift 6 21 Figure 6 10 Analyzer Diagnostics Menu Sheet 1 of 4...
Страница 268: ...SECTION 6 JLG CONTROL SYSTEM 6 22 JLG Lift 3121259 Figure 6 11 Analyzer Diagnostics Menu Sheet 2 of 4...
Страница 269: ...SECTION 6 JLG CONTROL SYSTEM 3121259 JLG Lift 6 23 Figure 6 12 Analyzer Diagnostics Menu Sheet 3 of 4...
Страница 270: ...SECTION 6 JLG CONTROL SYSTEM 6 24 JLG Lift 3121259 Figure 6 13 Analyzer Diagnostics Menu Sheet 4 of 4...
Страница 271: ...SECTION 6 JLG CONTROL SYSTEM 3121259 JLG Lift 6 25 Figure 6 14 Analyzer Personalities Menu Sheet 1 of 2...
Страница 272: ...SECTION 6 JLG CONTROL SYSTEM 6 26 JLG Lift 3121259 Figure 6 15 Analyzer Personalities Menu Sheet 2 of 2...
Страница 273: ...SECTION 6 JLG CONTROL SYSTEM 3121259 JLG Lift 6 27 Figure 6 16 Analyzer Machine Setup Menu...
Страница 274: ...SECTION 6 JLG CONTROL SYSTEM 6 28 JLG Lift 3121259 Figure 6 17 Analyzer Calibrations Menu...
Страница 289: ...SECTION 6 JLG CONTROL SYSTEM 3121259 JLG Lift 6 43 14 Press ENTER If calibration is successful the screen will read...
Страница 336: ...SECTION 6 JLG CONTROL SYSTEM 6 90 JLG Lift 3121259 NOTES...
Страница 346: ...SECTION 7 BASIC ELECTRICAL INFORMATION SCHEMATICS 7 10 JLG Lift 3121259 Figure 7 13 Connector Installation...
Страница 365: ...SECTION 7 BASIC ELECTRICAL INFORMATION SCHEMATICS 3121259 JLG Lift 7 29 This page left blank intentionally...
Страница 368: ...SECTION 7 BASIC ELECTRICAL INFORMATION SCHEMATICS 7 32 JLG Lift 3121259 NOTES...
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