1

PRINCIPLE & CONSTRUCTION PRINCIPLE & CONSTRUCTION

OF OF

HYDRAULIC PUMPSHYDRAULIC PUMPS

2

HYDRAULIC PUMPS

PRINCIPLE

CHARACTERISTICS

TYPES OF PUMPS

COMPARISON OF

PUMPS

TROUBLE SHOOTING

3

PUMP - PRINCIPLE

THE PRINCIPLE OF A HYDRAULIC PUMP IS TO CONVERT MECHANICAL ENERGY INTO HYDRAULIC ENERGY.

THIS IS ACHIEVED BY GENERATING AN INCREASED VOLUME DURING INTAKE AND DECREASED VOLUME ON THE DELIVERY SIDE.

5

PUMP CHARACTERISTICS

• FLOW RATING

• PRESSURE RATING

• VOLUMETRIC EFFICIENCY

• NOISE LEVEL

• CONTAMINATION LEVEL ALLOWED

6

TYPES OF PUMPS

NON POSITIVEDISPLACEMENT

PUMPS

GEAR PUMP VANE PUMP

ROTARY

AXIAL PISTONPUMP

RADIAL PISTONPUMP

RECIPROCATORY

POSITIVEDISPLACEMENT

PUMPS

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NON POSITIVE DISPLACEMENT PUMPS

INLETEYE

IMPELLER BLADES

OUTLET

OUTLET DIFFUSER

IMPELLER

PROPELLER

INLET

AXIAL (PROPELLER ) TYPE

CENTRIFUGAL ( IMPELLER ) TYPES

8

SINGLE VANE PUMP

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SINGLE VANE PUMP

DISCHARGE PORTSIDE PLATE

SHAFT

SUCTION PORT

BOLT

PRESSURE PLATESUCTION

ROTOR

DELIVERY

CAM RING VANE

Graphical Symbol

10

CARTRIDGE

PRESSURE PLATESIDE PLATE

CAM RING

LOCATING PINBOLT

11

VARIATION IN VANE PUMP DISPLACEMENT

CAMRING

ROTOR

“THROW” WIDTH

12

BALANCED VANE PUMP

INLET

OUTLET

INLET

DRIVE SHAFT

ROTOR

OUTLET

VANE

CAMRING

ROTATIONOUTLET

INL

ET

ROTATION

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VANE PUMP - TYPICAL PUMP CHARACTERISTICS

Pressure0 35 140 21017510570

10

0

30

20

0

10

kW HP

Inpu

t Pow

erOut

put F

low

L/min7570

30

3020

40

50

60

40

1200 r/min

1000 r/min

1500 r/min

1800 r/min

Kgf / Cm2

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VANE PUMP - TYPICAL PUMP CHARACTERISTICS

1200 r/min

1000 r/min

0 35 140 21017510570

Noi

se L

evel

60

55

50

45

65dB(A)

Pressure

PV2R2-41

Kgf / Cm2

Noise Level [One metre (3.3 ft.) horizontally away from pump head cover]

NOISE LEVEL

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DOUBLE VANE PUMP

DELIVERYSUCTION

DELIVERY

CARTRIDGE - 1 CARTRIDGE - 2Graphic Symbol

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EXTERNAL GEAR PUMP

INLET

OUTLET

DRIVE GEARDRIVEN GEAR

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EXTERNAL GEAR PUMP

INLET

OUTLET

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LOBE PUMP

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INTERNAL GEAR PUMP

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SINGLE PUMPS

DISCHARGE PORT

ROTOR

PRESSURE PLATESUCTION PORT

SIDE PLATE

WAVE WASHER

SHAFT

CAM RING

VANE

PROPORTIONAL PRESSURE REDUCING VALVE

Graphical Symbol

23

VARIABLE DISPLACEMENT PISTON PUMPS

SHAFT

YOKE

SWASH PLATE

PIVOT

CONTROL PISTON

DRAIN PORTSPOOL

FLOW ADJ. SCREW

DISCHARGE PORT

SUCTION PORT

PISTON ASSEMBLY

PRESSURE ADJ. SCREW

FILLING PORT PLUG

CYLINDER BLOCK

Graphical Symbol

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CYLINDER BLOCK ASSEMBLY

PIVOT

WASHER

SLIPPER RETAINER

CYLINDER BLOCK

WASHER

SPRING

WASHER

RETAINING RING

PISTON ASSEMBLY

PIN (3 pcs.)

25

CYLINDER BLOCK ASSEMBLY

PORT PLATE

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VARIABLE DISPLACEMENT PISTON PUMPS( AT FULL CUT - OFF )

.

PRESSURE COMPENSATOR TYPE

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VARIABLE DISPLACEMENT PISTON PUMPS PRESSURE COMPENSATOR CONTROL

SPOOL

PRESSURE ADJUSTMENT SCREW

DELIVERY ADJUSTMENT SCREW

YOKEINLET

OUTLET

Suction Cycle

Discharge Cycle

OPERATING PISTON

Section A-AIN

OUT

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VARIABLE DISPLACEMENT PISTON PUMPS PRESSURE COMPENSATOR CONTROL

IN

OUT

OPERATING PISTON

INLET

OUTLET

Suction Cycle

Discharge Cycle

Section A-A

A

A

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VARIATION IN PUMP DISPLACEMENT

MAXIMUM SWASH

PLATE ANGLE

( MAXIMUM DISPLACEMENT )

DECREASED SWASH

PLATE ANGLE

( PARTIAL DISPLACEMENT )

ZERO SWASH

PLATE ANGLE

( ZERO DISPLACEMENT )

STROKE LENGTH

STROKE LENGTH

NO STROKE

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SWASH PLATE CAUSES PISTON TO RECIPROCATE

DRIVE SHAFT

SWASH PLATE

SHOE PLATE

PISTON SUB-ASSEMBLY

CYLINDER BLOCK BORE

VALVE PLATE SLOT

INLET PORT

OUTLET PORT

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VARIABLE DISPLACEMENT PISTON PUMP - TYPICAL CHARACTERISTICS

Typ e "A R 1 6 " 2 V is cos ity 2 0 m m /s (10 0 S S U ) [IS O V G 3 2 O ils, 50 °C (1 22 °F )]

Eff

icie

ncy

100

80

60

kW8

6

420

HP1210

420

68

Inpu

t Pow

er

% N=1500 r/min

30

10

0

20

Out

put F

low

L/min

0 40 80 120 160

Pressure

Input Power

Output Flow

Volumetric EfficiencyOverall Efficiency

Performance Characteristic Curve

Kgf/Cm2

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VARIABLE DISPLACEMENT PISTON PUMP - TYPICAL CHARACTERISTICS

kW

12

10

4

2

0

6

8

Inpu

t Pow

er

HP 10

4

2

0

6

8

0 5 10 15 25L/min

Output Flow20 30

N=1500 r/min

P= 140P= 120

P= 100P=80P=60P=40P=20P= 7

P=Kgf / Cm2

Input Power

Typ e "A R 1 6 " 2 V is cos ity 2 0 m m /s (10 0 S S U ) [IS O V G 3 2 O ils, 50 °C (1 22 °F )]

0 8040 160120

Full Cut-off PressureF

ull C

ut-o

ff P

ower

kW2.0

1.5

0

1.0

HP1.5

0

0.5

1.0

0.51500 r/min

1800 r/min

Full Cut-off Power

Kg / Cm2

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VARIABLE DISPLACEMENT PISTON PUMP - TYPICAL CHARACTERISTICS

Typ e "A R 1 6 " 2 V is cos ity 2 0 m m /s (10 0 S S U ) [IS O V G 3 2 O ils, 50 °C (1 22 °F )]

DrainNoise Level [One metre (3.3 ft.) horizontally away from pump head cover]

1.5

0

0.5

1.0

2.0

0 8040 160120

Pressure

Full Cut-off

Full Flow

N=1800 r/min

N=1500 r/min

1500,1800 r/min

Dra

in

L/min

Kgf / Cm2

Full Cut-off

Full Flow

Pressure

0 8040 160120

dB(A)80

50

60

70

40

Noi

se L

evel

N=1500 r/min

Kgf / Cm2

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BENT AXIS PISTON PUMP

PISTON

PISTON ROD UNIVERSAL LINK

CYLINDER BLOCK

FROM INLETTO OUTLET

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COMPARISON OF HYDRAULIC PUMPS

TYPE VANE PUMP GEAR PUMP PISTON PUMP

WorkingPrinciple

VaryingVolumebetween theVane &Camring

ShiftingVolume

surrounded bygear grooves &casing.

VaryingVolume byreciprocatingPistons.

AverageEfficiency

High Low except forpressureloading type.

Highest amongthree types.

Wear &Efficiency

Does notdecrease sincewearing ofcamring or

vane can becompensated

Decreases withWear

Decreases withWear

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COMPARISON OF HYDRAULIC PUMPS

T Y P E V A N E P U M P G E A R P U M P P I S T O N P U M P

S e n s i t i v i t y t od u s t

S e n s i t i v e t or e l a t i v e l ys m a l l d u s tp a r t i c l e s , b u tl e s s a f f e c t e dt h a n p i s t o nt y p e .

L o w p r e s s u r et y p e i s l e s sa f f e c t e d , w h i l et h e p r e s s u r el o a d i n g t y p e i ss e n s i t i v e .

M o s t s e n s i t i v es i n c ec o m p o n e n t sa r e a s s e m b l e dw i t h s m a l lc l e a r a n c e

A p p l i c a b i l i t y o fv a r i a b l e

d i s p l a c e m e n tt y p e

P o s s i b l e N o t P o s s i b l e P o s s i b l e

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COMPARISON OF HYDRAULIC PUMPS

T Y P E V A N E P U M P G E A R P U M P P I S T O N P U M P

L i f e o fB e a r i n g

B e a r i n g l i f e i sv e r y l o n gb e c a u s ep r e s s u r eb a l a n c i n g t y p ei s u s e d w h i c hd o e s n o t a p p l yl o a d t o b e a r i n g .L o a d i s a p p l i e dt o b e a r i n g i nc a s e o fv a r i a b l e t y p e .

L i f e i s s h o r tb e c a u s e a l a r g ea m o u n t o f l o a di s a p p l i e d .

A l a r g e a m o u n to f l o a d i s b e i n ga p p l i e d t ob e a r i n g s .M o r e b e a r i n g sa r e g e n e r a l l yu s e d .

38

COMPARISON OF HYDRAULIC PUMPS

T Y P E V A N E P U M P G E A R P U M P P I S T O N P U M PD e t e r i o r a t i o n o fE f f i c i e n c y

E f f i c i e n c y d o e sn o t d e t e r i o r a t ed u r i n g t h es e r v i c e l i f e o fm o v i n g p a r t sb e c a u s e o f w e a rc o m p e n s a t i n gt y p e .

D e t e r i o r a t e s a sm o v i n g p a r t sw e a r .

A l m o s t s a m e a sg e a r p u m p .

N o i s e N o i s e i sg e n e r a l l y l o w .B u t s i n g l e s t a g eh i g h p r e s s u r ep u m p m a k e m o r en o i s e .

G e n e r a l l y h i g h . L o w N o i s e .

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COMPARISON OF HYDRAULIC PUMPS

TYPE PRESSUREDISCHARGEMAX. SPEED OVERALLEFFICIENCY

(Kgf/Cm2) ( L / min ) ( rpm ) ( % )

GEAR PUMP 20 ~ 210 7 ~ 570 1800~7000 75 ~ 90

VANE PUMP 20 ~ 210 2 ~ 950 2000~4000 75 ~ 90

AXIALPISTONPUMP

70 ~ 350 2 ~ 1700 600 ~ 6000 85 ~ 95

RADIALPISTONPUMP

50 ~ 250 20 ~ 700 700 ~ 1800 80 ~ 92

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TROUBLE SHOOTINGPRESSURE NOT DEVELOPING

CHECK DIRECTION OF PUMPROTATIONCONDITION OF OIL SURFACE( COLOUR WHITE / YELLOW )

SIZE OF SUCTION STRAINER

CHECK PRESSURE CONTROLVALVECHECK CARTRIDGE FORDAMAGENOISE

CAVITATION WRONG ALIGNMENT

MECHANICAL VIBRATION HIGH FREQUENCY NOISE

HARMONIC NOISEFROM TANK SURFACE/ PIPE MANIFOLDCONDITION OF OIL ( AIRBUBBLES / COLOUR OF OILWHITE OR YELLOW )