6.
HYDRAULIC SYSTEM
6-
5
-2
2. Theory of operation
1) Pump function
• The cylinder barrel, which is splined to the drive shaft, revolves with the shaft.
• The pistons installed into the cylinder barrel, following the sliding surface of the swash plate, make a reciprocating
motion, which causes the volume of the plunger to change, thereby enabling the intake and discharge pumping
operations.
• As the plunger moves from the bottom dead center to the top dead center, the volume of it is increased and oil
flowing from the intake port runs through the valve plate into the cylinder barrel. (Intake stroke)
• As the plunger moves from the top dead center to the bottom dead center, the volume of it is reduced, the oil in the
cylinder barrel is discharged to the discharge port. (Discharge stroke)
• By changing the inclination of the swash plate sliding surface, the plunger stroke is changed and thus the displace-
ment of the plunger can be changed.
• Oil taken in from the inner ports of the cylinder barrel is discharged from the inner discharge ports of the valve
plate.
• Oil taken in from the outer ports of the cylinder barrel is discharged from the outer discharge ports of the valve
plate.
• Oil discharged from the outer (inner) discharge port of the valve plate flows to P1 (P2) port of the pump assembly.
051799-00EN00
α
Piston
Bottom dead center
Valve plate
Discharge ports
Cylinder barrel
Top dead center
Intake stroke
Discharge
stroke
Intake port
P1
P2
Swash plate
Summary of Contents for ViO12-2A
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Page 109: ...5 3 1 5 ELECTRIC SYSTEM 5 3 Wiring Diagram...
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Page 219: ...6 HYDRAULIC SYSTEM 6 7 8 1 4 3 8 7 12 10 10 15 a b c Loctite 262 0 30Nm 0 45Nm...
Page 348: ...7 ADJUSTMENT AND REPAIR 7 5 31 6 Control Levers Pilot valves Control valve...
Page 349: ...7 ADJUSTMENT AND REPAIR 7 5 32 7 Upperstructure Implement Bucket cylinder Arm cylinder...
Page 351: ...7 ADJUSTMENT AND REPAIR 7 5 34 9 Undercarriage High speed travel solenoid valve...
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Page 360: ...CHAPTER 8 PERIODIC INSPECTION AND SERVICING 8 1 List of Periodic Inspection and Servicing 8 1...
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Page 364: ...CHAPTER 9 FUEL LUBE OIL AND GREASE RECOMMENDED 9 Fuel Lube Oil and Grease Recommended 9 1...
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Page 406: ...CHAPTER 11 REFERENCE DATA 11 1 Specifications for Attachment 11 1...
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