hps_ii
DESCRIPTION
Hydraulic 2TRANSCRIPT
2005/2006 I. Hydraulic and Pneumatic Systems 1
Hydraulic energy convertersPumps and motors
There is a geometrical volume which is in principle displaced: Vg
The ideal (geometrical) flow rate is: Qg = n·Vg
There are other effects which reduce the flow rate:
Qc – compressibility
Qe – gas and vapour enclosures
Qr = Q – Qc – Qe
but these are neglected in the practice.
In reality there are leakages: Q = vol·Qg
General:
Q
Δp Qg
n1 < n2
Q
2005/2006 I. Hydraulic and Pneumatic Systems 2
M
n
Mmot
Mf
Mth
Mm+Mi
Hydraulic energy convertersPumps and motors
pV
MpQMP gthgthth
2
M
n
Mpump
Mf Mm+Mi
Mth
Pump Motor
ifmth MMMMM ifmth MMMMM Losses: m – mechanical, f – friction, i – inertial
Degree of irregularity:avQ
QQ minmax
2005/2006 I. Hydraulic and Pneumatic Systems 3
Hydraulic pumps and motorsPump types:
Gear Pumps
Off-centered internal gear
pump
Centered internal
gear pump / gerotor pump
Screw pump
Vane pump
(forgó vezérlőpályás,
külső beömlésű)
(álló vezérlőpályá
s, külső beömlésű)
Radial Piston Pumps
External gear pump
Axial Piston Pumps
Tilting block
Stationary cylinder block
Rotating cylinder block
Tilting cam plate
2005/2006 I. Hydraulic and Pneumatic Systems 4
Hydraulic pumps and motorsMotor types:
Properties:• generally high speed (n= 500-10.000 min-1)
• low speed high torque - LSHT (n= 0,5-1.000 min-1)
Gear motor
Gerotor motor
Vane motor
Radial piston motor
Internal radial piston motor with multiple stroke
Bent axis piston motor
Standing shaft, multiple stroke
Standing housing, multiple stroke
Tilting cam plate / swash plate
Axial piston motors
Fogazott-gyűrűs vagy
bolygókerekes motor
Radiál-dugattyús motor belső dugattyú támasztással
Többlöketű radiál-dugattyús motor külső dugattyú támasztással
Axiáldugattyús motor ferde tengelyes kivitelben
Állótengelyes többlöketű axiáldugattyús motor
Állóházas többlöketű axiáldugattyús motor
Axiáldugattyús motor ferdetárcsás kivitelben
2005/2006 I. Hydraulic and Pneumatic Systems 5
Gear pumps
Gear pumps - function:Delivery is done by the fact that less volume is enclosed in the room between the teeth than delivered at the outer edge.
The geometrical displacement volume is the difference of the two.
)2(2or 4 2 xzmbVrRrbV gg
where R is the outer radius,
r is the radius of the last contact point;
b is the breadth;
z is the number of teeth
m is the module
x is a profile constant
Rr
2005/2006 I. Hydraulic and Pneumatic Systems 6
Gear pumpsProperties
T T t
Q
driving gear
driven gear
total flow rale
Simple and robust
Cheap
Reliable, little sensitivity to dirt
Operation is independent of the position
Good suction characteristics
Good efficiency, up to 90%
Large rotational speed domain: n = 500 – 6000 1/min
Gear motors identical
Noisy, uneven, vibration, strong pulsation
Max pressure 250 bar
Max flow rate 160 l/s
2005/2006 I. Hydraulic and Pneumatic Systems 7
Gear motorsFunction:
Feladatuk• hidraulikus energiát mechanikai energiává alakítanak• nyomás fajlagos nyelőtérfogat nyomatékigény• térfogatáram fajlagos nyelőtérfogat fordulatszám
Fontos jellemzők:
Elnyelt térfogat kb. 1-200 cm3
Max. üzemi nyomás 300 bar-igFordulatszám tartomány 500-10000 min-
1Gear motors
Important properties:
Displacement ca. 1-200 cm3
Max. pressure 300 barSpeed 500-10 000 min-1
Tasks:• convert hydraulic energy into mechanical energy• pressure specific displacement wanted torque• flow rate specific displacement speed
Aspects of selection:• pressures• speed• variability of displacement• installation conditions• lifespan• maintenance conditions• allowed noise level• price Kiválasztási
szempontok• nyomás-tartomány• fordulatszám-tartomány• munkatérfogat változtat- hatósága• beépítési feltételek• élettartam• karbantartási feltételek• megengedett zajszint• beszerzési ár
2005/2006 I. Hydraulic and Pneumatic Systems 8
Screw pumps
Properties, function:
Larger losses because of a longer path, larger friction
High costs because of low tolerances, sensitivity to viscosity
4
2sin
3604222
sDsdDVg s: pitch
Max flow rate: 3000 l/s
Max pressure: 170 bar
= 0,65-0,7
There are no screw motors
No pulsations, no noise, continuous operation
2005/2006 I. Hydraulic and Pneumatic Systems 9
Vane pumps
Pump types:
a) Single acting – displacement volume adjustable
b) Double acting – displacement volume constant
szDebVg 2 for single acting pumps, s is the thickness of the vanes
D: maximum diameter of the inner curve
d: minimum diameter of the inner curve
a) b)
Vanes can be pressed against circumference by springs or by pressure
24
22 dDzbkdDkbVg
for multiple acting pumps
k: number of the excentricity bulges (usually 2)
2005/2006 I. Hydraulic and Pneumatic Systems 10
Vane pumpsProperties
Since there is no natural limit to the pressure, a relief valve is necessary if the limit is reached.
• Relatively silent but noisier than a screw pump
• Max Q: 600 l/min, max p: 140 bar, >0,7
• Significant wear because of sliding surfaces
• Small size increase – large volume (Vg) increase
• Cheap
• Relatively large leakage losses
Use as motor is rare but then as constant n motor
Q
Δp
2005/2006 I. Hydraulic and Pneumatic Systems 11
Radial piston pumps
Pump types:
o with valve o without valve
• The shaft and the excentric rotate, the rest is stationary. There are two valves. There is a semicircular slit where the fluid can enter into the cylinder.
• Many different forms
• Max Q: 600 l/min, max p: 630 bar, = 0,8-0,9
Here with valve:
2005/2006 I. Hydraulic and Pneumatic Systems 12
Radial piston pumps
Properties:
• Long life, low wear because of good lubrication
• Higher noise, uneven delivery
• Sensitive to contamination
• Excentricity can be governed, over 0 too
• For motor applications mostly at low speed, 1-10 rpm
• Relative bulky
zed
Vg 24
2
2005/2006 I. Hydraulic and Pneumatic Systems 13
LSHT motorsConstruction of one stroke radial piston motors:
LSHT egylöketű radiáldugattyús motorok felépítése
Radial piston motors of MR-typeMR típusú radiáldugattyús motorok
Fontos jellemzők:Elnyelt térfogat 10-8500 cm3
Max. üzemi nyomás 300 bar-igFordulatszám tartomány 0,5-2000 min-1
Max. forgatónyomaték 32000 Nm-ig
Important properties:Displacement 10 - 8500 cm3
Max. pressure 300 barSpeed 0,5 - 2000 min-1
Max. torque to 32000 Nm
2005/2006 I. Hydraulic and Pneumatic Systems 14
Axial piston pumps
Pump types:
Tilting cam plane
• Compact, small weight
• Good efficiency
• Long life
• Used more as motors than as pumps
• Can be governed through 0 exchange of delivery direction
• Vg is often adjustable by the angle
• η = 0,8-0,9; Δpmax = 315 bar; Qmax = 1200 l/min4
tan2 d
DzV kg
Tilting block
Properties:
2005/2006 I. Hydraulic and Pneumatic Systems 15
Axial piston pumps
Adjusting mechanisms
V
s
The Vg and thus Q can be governed or controlled through various mechanisms:
a) Governing mechanisms:
• Mechanical (by hand)
• Electromechanical (by electromotor)
• hydraulic
In all the three cases it has to be ensured that the maximum angle or displacement is not overstepped.
2005/2006 I. Hydraulic and Pneumatic Systems 16
Axial piston pumps
Adjusting mechanisms (cont.)
b) Control mechanisms:
• Zero displacement control (energy saving): provides exactly the necessary flow rate which covers the leakage flow
• Pressure control: provides a constant pressure independently of Vg
• Flow control: provides a constant flow rate - can use Vg or n control
• Power control: provides a constant power (more complicated)
2005/2006 I. Hydraulic and Pneumatic Systems 17
Big pictures
End of normal presentationBeginning of big pictures
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Pump types
External gear pump
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Pump types
Off-centered internal gear pump
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Pump types
Centered internal gear pump / gerotor pump
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Pump types
Screw pump
2005/2006 I. Hydraulic and Pneumatic Systems 22
Pump types
Vane pump
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Pump types
Radial piston pump with stationary cylinder block
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Pump types
Radial piston pump with rotating cylinder block
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Pump types
Axial piston pump with tilting block
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Pump types
Axial piston pump with tilting cam plate
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Hydraulic motor types
Gear motor
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Hydraulic motor types
Gerotor motor
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Hydraulic motor types
Vane motor
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Hydraulic motor types
Radial piston motor
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Hydraulic motor types
Internal radial piston motor with multiple stroke
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Hydraulic motor types
Bent axis piston motor
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Hydraulic motor types
Axial piston motor with tilting cam plate
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Hydraulic motor types
Axial piston motor with fixed shaft, multiple stroke
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Hydraulic motor types
Axial piston pump with fixed housing, multiple stroke
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External gear pump
Function: Külsőfogazású fogaskerékszivattyú működése
G2, G3 és G4 típusú fogaskerék-szivattyúkFontos jellemzők:
Kiszorított térfogat 0.2-200 cm3
Maximális nyomás 300 bar (NG szerint)Fordulatszám tartomány 500-6000 min-1
Back
Important properties:Displacement 0,2 - 200 cm3
Max. pressure 300 bar (by NG)Speed 500 - 6000 min-1
Gear pumps of G2-, G3- and G4-type
Mainly used in the mobile hydraulics.• relative large pressure• small weight• wide speed range• wide temperature range• wide viscosity range• high noise level• unfavourable efficiency
Főként a mobilhidraulikában alkalmazzák.• viszonylag nagy nyomás• kis tömeg• széles fordulatszám tartomány• széles hőmérséklet tartomány• széles viszkozitás tartomány• magas zajszint• kedvezőtlen hatásfok
2005/2006 I. Hydraulic and Pneumatic Systems 37
External gear pump
Construction
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External gear pump
Construction
2005/2006 I. Hydraulic and Pneumatic Systems 39
Internal gear pump
Function Belsőfogazású fogaskerékszivattyú működése
Stabilhidraulikában alkalmazzák.• alacsony zajszint• egyenletes szállítás• jó szívóhatás
GU típusú belső fogazású fogaskerékszivattyú
Mainly used in industrial hydraulics.
• low noise level
• smooth flow
• high suction heads
Important properties:Displacement 3 - 250 cm3
Max. pressure 300 bar (by NG)Speed 500 - 3000 min-1
Fontos jellemzők:
Kiszorított térfogat 3-250 cm3
Üzemi nyomás 300 bar (NG szerint)Fordulatszám tartomány 500-3000 min-1
Back
2005/2006 I. Hydraulic and Pneumatic Systems 40
Internal gear pump
Construction
1 Housing 2 Flange 3 Shaft with external tooth gear
4 Internal tooth gear
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Internal gear pump
Construction
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Gear pump
Function
Rr
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Gear motor
Construction
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Gear motor
Construction
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Screw pump
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Vane pumps
Double acting
Lapátos szivattyúk működése
7. lapát mögött nyomás 8. kenés miatt kettős lapát 9. horony a lapátcsúcshoz
2. kétszeresen excentrikus gyűrű
3. szívás kezdete 4. maximális térfogat 5. kiszorítás
6. kettős löket
AA1FF
Back
Elliptical cam ring Double
stroke
Start of suction Maximal displacement Discharge
Pressure behind the vane
Dual vane for lubrication
Chamfer to the vane top
2005/2006 I. Hydraulic and Pneumatic Systems 47
Vane pumps
Single acting
Lapátos szivattyúk felépítése
Közvetlen vezérlésű szárnylapátos szivattyú
Közvetlen vezérlésű (bal) és elővezérelt (jobb)
V3 és V5 típusú szárnylapátos szivattyúk
Back
Rotor and vanes
Directly controlled (left) and pilot-operated vane pump (right)
Directly controlled vane pump
Vane pumps of V3- and V4-type
Important properties:Displacement 5 - 100 cm3
Max. pressure 100 barSpeed 1000 - 2000 min-1
2005/2006 I. Hydraulic and Pneumatic Systems 48
Vane pump
Elliptical cam ring
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Vane pump
Start of suction
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Vane pump
Maximal displacement
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Vane pump
Discharge
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Vane pump
Double stroke
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Vane pump
Pressure behind the vane
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Vane pump
Dual vane for lubrication
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Vane pump
Chamfer to the vane top
AA1FF
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Vane pump
Rotor and vanes
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Vane pump
Direct controlled (left) and pressure compensated (right) vane pump
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Vane pump
Direct controlled vane pump
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Vane pump
Construction
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Radial piston pump
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Radial piston pumps
With internal eccentric shaft Radiál-dugattyús szivattyú belső
dugattyútámasztással
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Radial piston pumps
Working phases
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Radial piston pumps
Radial piston pumps of R4-type
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Radial piston pumps
Pulsation of the flow rate with 1, 2, 3, 4 pump elements
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Radial piston motors
LSHT motor of MR-type
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Radial piston motors
LSHT motor of MR-type
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Radial piston motors
LSHT motor of MR-type
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Radial piston motors
LSHT motor of MR-type
2005/2006 I. Hydraulic and Pneumatic Systems 69
Axial piston pumpsAxial piston pumps with tilting cam plate - Principle of operation -
A ferde tárcsa elve állandó vagy változtatható billenési szöggel
Állítható térfogatáramú szivattyú elektromos-hidraulikus állítással, fordulatszám-függő
szabályozássalés ráépített segédszivattyúval
Variable displacement axial piston pump with speed dependent electro-hydraulic
adjustment and booster motor Principle of tilting cam plate with fixed and variable angle
2005/2006 I. Hydraulic and Pneumatic Systems 70
Axial piston pumpsAxial piston pumps with tilting cam plate
Állítható szivattyú zárt körfolyamathoz, A4VG típus
Állítható szivattyú nyitott körfolyamathoz, A10VO típus
- Constructions -
Back
Adjustable pump for open circuit, A10VO-type
Adjustable pump for close circuit, A4VG-type
2005/2006 I. Hydraulic and Pneumatic Systems 71
Axial piston pumps
With tilting cam plate
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Axial piston pumps
With tilting cam plate
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Axial piston pumps
With tilting cam plate
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Axial piston pumps
With tilting cam plate
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Axial piston pumps
Drive shaftPistonsPiston surfaceStroke lengthCam plate
AngleCylinder barrel
Port plate
Outlet port
Inlet port
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Axial piston pumps
Pump types: Axial piston pumps with tilting cam plane
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Axial piston pumps
With tilting cam plate
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Axial piston pumpsAxial piston pumps with tilting block
Állandó folyadékszállítású egység kúpos dugattyús hajtóművel A ferde tengely elve állandó vagy változtatható billenési szöggel
- Principle of operation -
Fixed displacement pumpPrinciple of bent axis with fixed or variable
angle
2005/2006 I. Hydraulic and Pneumatic Systems 79
Axial piston pumpsAxial piston pumps with tilting block - Constructions -
Ferde tengelyű, kúpos dugattyús hajtómű 40°-os technológiával készítve,
rögzített billenési szöggel
A2F típusú állandó térfogatáramú egység (a billenési szög rögzített), mint szivattyú
vagy motor nyitottés zárt körfolyamokhoz
A7VO típusú változtatható térfogatáramú egység (a billenési szög állítható), mint
szivattyúnyitott körfolyamokban
Bent axis piston pump made with 40° angle
technology, fixed angle
Adjustable pump of A7VO-type for open circuit
Fixed flow rate pump of A2F-type for open or closed circuit (also as
motor)
Back
2005/2006 I. Hydraulic and Pneumatic Systems 80
Axial piston pumpsWith tilting block
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Axial piston pumps
With tilting block
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Axial piston pumps
With tilting block
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Axial piston pumps
With tilting block
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Axial piston pumps
With tilting block
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Axial piston pumps
With tilting block
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Axial piston pumps
With tilting block
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Axial piston pumps
With tilting block