applications of hydraulics&pneumatics : session 12
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12pplications of
Hydraulic Pneumatics&By: Alireza Safikhani
2 Applied Circuits
Actuators
Pneumatic actuators are made in a w ide variety ofPneumatic actuators are made in a wide variety of
sizes, styles and types including the followingsizes, styles and types including the following
Single acting with and w ithout spring returnSingle acting with and w ithout spring return
Double actingDouble acting
Non cushioned and fixed cushionedNon cushioned and fixed cushioned
Adjustable cushionedAdjustable cushioned
MagneticMagnetic
RodlessRodless
RotaryRotary
ClampingClamping BellowsBellows
Double acting magnetic
A magnetic band around the circumference of theA magnetic band around the circum ference of the
piston operates reed switches to indicate positions ofpiston operates reed switches to indicat e positions of
stroke.stroke.
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Clamping cylinder
Normally sprungNormally sprung instrokedinstroked
Click the illustration to start and stop animation
Clamping cylinder
Double acting double ended piston rodDouble acting double ended piston rod
Click the illustration to start and stop animation
Non rotational guiding
For applications where loadsFor applications where loads
attached to the piston rodattached to the piston rod
end need guiding toend need guiding to
maintain orientationmaintain orientation
Guided compact cyl indersGuided compact cyl indersincorporate twin guide barsincorporate twin guide bars
running in bearings withinrunning in bearings within
the extruded cyl inder bodythe extruded cyl inder body
Non rotational guiding
ISO 32 to 100 bore cyl inders with non rotating piston rod.ISO 32 to 10 0 bore cyl inders with non rotating piston rod.
Feature continuous flats running the length of the rod w hichFeature continuous flats running the length of the rod w hich
run in a matching bearing.run in a matching bearing.
For resisting lightFor resisting light torsionaltorsional loads only.loads only. twist in antwist in an outstrokedoutstroked rod can occur at higher torque.rod can occur at higher torque.
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Non rotational guiding
Add on guide block unitsAdd on guide block units
with sl ide or rol lerwith sl ide or rol ler
guides.guides. provide non rotationalprovide non rotational
guiding and greaterguiding and greater
support against highersupport against higher
loads.loads.
For low friction and bestFor low friction and best
support use the versionsupport use the version
with tw in rol ler guideswith tw in rol ler guides
These units can be fittedThese units can be fitted
with tw in passive orwith tw in passive oractive locking cartridges.active locking cartridges.
Non rotational guiding
Linear slide units.Linear slide units.
For precise actuationFor precise actuation
high quality sl idehigh quality slidebearingsbearings
provide exceptionalprovide exceptional
torsionaltorsional rigidity with arigidity with a
tw in throughtwin through--rod layoutrod layout
magnetic pistonmagnetic piston
choice of port connectionchoice of port connection
positions.positions.
Locking and braking
For safety in the event of airFor safety in the event of air
failure or as part of afailure or as part of a
machine sequence.machine sequence.
Stop and hold a load at anyStop and hold a load at any
position in the stroke.position in the stroke.
Passive or active piston rodPassive or active piston rod
locking unitlocking unit
A range of these add onA range of these add on
units is designed to suit ISOunits is designed to suit ISO
cylinders from 32 mm to 125cylinders from 32 mm to 125
mm bore.mm bore.
Rodless Cylinders
RodlessRodless cylinders for:cylinders for:
Limited spacesLimited spaces
Simple instal lationSimple instal lation
Long strokesLong strokes
Neat attractive styl ingNeat attractive styl ing
High speedHigh speed
Precision controlPrecision control
Large range:Large range:
Variants in structuralVariants in structural
strengthstrength
Twin strokeTwin stroke
Active brakin gActive brak ing
Passive brakingPassive braking
Curved designCurved design
Electric driveElectric drive
Corrosion resistantCorrosion resistant
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Operating principle
The sealing strips are parted and closed as theThe sealing strips are parted and closed as the
piston moves through the strokepiston moves through the stroke
Adjustable cushionsAdjustable cushions Dual connection ports at the left hand endDual connection ports at the left hand end
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Rodless applied
For action across a stripFor action across a strip
processprocess
No overhang or mechanismNo overhang or mechanismrequired compared to arequired compared to a
conventional pistonconventional piston
rod cyl inderrod cyl inder
The application shows aThe application shows a
flying knife typical of use inflying knife typical of use in
the paper productionthe paper production
industryindustry
Rodless applied
Lifting in places with l imitedLifting in places with l imited
headroomheadroom
Actuation contained w ithinActuation contained w ithin
the length of the cyl inderthe length of the cyl inder
bodybody
Rodless Overview
Extruded aluminium alloyExtruded aluminium alloy
cylinder barrel with integralcyl inder barrel with integral
bearing guidesbearing guides
Internally or externallyInternally or externally
guided carriageguided carriage
Roller guided carriageRoller guided carriage
Double carriagesDouble carriages
Integral valve optionIntegral valve option
Bore sizes 16 to 80mmBore sizes 16 to 80mm
Strokes up to 8.5 mStrokes up to 8.5 m
Adjustable cushionAdjustable cushion
Single end connectionsSingle end connections
Magnetic piston optionMagnetic piston option
Dual integral grooves forDual integral grooves for
sensor mountingsensor mounting
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Bellows
Double convolution typeDouble convolution type
Speed control
The maximum natural speed of a cyl inder is determined by:The maximum natural speed of a cyl inder is determined by:
the cylinder size,the cylinder size,
the ports size,the ports size, inlet and exhaust valve flow,inlet and exhaust valve flow,
the air pressure,the air pressure,
the bore and length of the hoses,the bore and length of the hoses,
the load against which the cyl inder is working.the load against which the cyl inder is working.
Speed control
Once a valve, cylinder, pressure and load are selected ,Once a valve, cylinder, pressure and load are selected ,
adjustable speed control is effected with flow regulators.adjustable speed control is effected with flow regulators.
Speed is regulated by control l ing the flow of air to exhaustSpeed is regulated by control l ing the flow of air to exhaust
The front port regulator controls the outstroke speed and theThe front port regulator controls the outstroke speed and the
rear port regulator controls therear port regulator controls the instrokeinstroke speed.speed.
Increasing speed
In some applicationsIn some applications
cylinder speed can becylinder speed can be
increased by 50% whenincreased by 50% when
using a quick exhaust valve.using a quick exhaust valve.
When operated, air from theWhen operated, air from thefront of the cylinderfront of the cylinder
exhausts directly throughexhausts directly through
the quick exhaust valve.the quick exhaust valve.
Built in cushioning wil l beBuilt in cushioning wil l be
less effective.less effective.
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Cylinder air consumption
To estimate the total average air consumption of aTo estimate the total average air consumption of a
pneumatic system make a calculation for eachpneumatic system make a calculation for each
cylinder in the system. Add these together and addcylinder in the system. Add these together and add5% .5% .
It is important to understand that the instantaneousIt is important to understand that the instantaneous
flow requirement for a system will be higher thanflow requirement for a system will be higher than
the average and in some cases very much higher.the average and in some cases very much higher.
Table of consumption Take each figureTake each figure
and multiply byand multiply by
the stroke in mm .the stroke in mm .
For pressuresFor pressuresother than 6 barother than 6 bar
multiply by themultiply by the
absolute pressureabsolute pressure
divided by seven.divided by seven.
stroke at 6 bar
Boremm
Rodmm
Push strokeconsumptiondm3/mm of
stroke at 6 bar
Pull strokeconsumptiondm3/mm of
Combinedconsumptiondm3/mm ofstroke/cycle
10 4 0.00054 0.00046 0.00100
12 6 0.00079 0.00065 0.00144
16 6 0.00141 0.00121 0.00262
20 8 0.00220 0.00185 0.00405
25 10 0.00344 0.00289 0.00633
32 12 0.00563 0.00484 0.01047
40 16 0.00880 0.00739 0.01619
50 20 0.01374 0.01155 0.02529
63 20 0.02182 0.01962 0.04144
80 25 0.03519 0.03175 0.06694
100 25 0.05498 0.05154 0.10652125 32 0.0859 0.08027 0.16617
160 40 0.14074 0.13195 0.27269
200 40 0.21991 0.21112 0.43103
250 50 0.34361 0.32987 0.67348
Table of thrust and pulls d/a
Cylinderbore mm(inches)
Piston roddiameter
mm (inches)
Thrust N at6 bar
Pull Nat 6 bar
8 3 30 25
10 4 47 39
12 6 67 50
16 6 120 10320 8 188 158
25 10 294 246
32 12 482 414
40 16 753 633
44.45 (1.75) 16 931 810
50 20 1178 989
63 20 1870 1681
76.2 (3) 25 2736 2441
80 25 3015 2721
100 25 4712 4418
125 32 7363 6881
152.4 (6) (1 1/2) 10944 10260
160 40 12063 11309
200 40 18849 18095
250 50 29452 28274
304.8 (12) (2 1/4) 43779 42240
320 63 48254 46384
355.6 (14) (2/14) 59588 58049
The pull values are lowerdue to the annular area ofthe piston
The values shown hereare for a working pressureof 6 bar
For another pressure inbar, multiply the thrustvalues in the table by thatpressure then divide by 6