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8/14/2019 Pneumatic Components & Systems 2008
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Pneumatic Components &Systems
Team 1640
Clem McKownmentorNovember 2008
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Topics What are pneumatics?
What are pneumatics good for?
How pneumatics work
The pneumatic system
Variations on the theme
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What are pneumatics Mechanisms which
use air pressure to
apply mechanicalforce anddisplacement (work)
The pneumatic
devices we use arebasically binaryactuatorseitherretracted orextended
Retracted
Cylinder
ExtendedCylinder
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What are pneumatics good for? Mechanisms requiring (2) discrete states
Gear shifters
Gripper articulation
Lifters
Brakes
and a significant force or displacement
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Strengths
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Strengths Simple
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Strengths Simple
Easy to control
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Strengths Simple
Easy to control
Can apply a lot of force from a small, lightpackage
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Strengths Simple
Easy to control
Can apply a lot of force from a small, lightpackage
Force is limited by air pressure and cylinder
diameter
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Strengths Simple
Easy to control
Can apply a lot of force from a small, lightpackage
Force is limited by air pressure and cylinder
diameter No adverse consequence if cylinder is
stopped (no stalled motors) or reversedcompressed air is a spring
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Drawbacks
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DrawbacksA significant weight investment (~10
lbm) in a pneumatic system is needed
for the first pneumatic device
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DrawbacksA significant weight investment (~10
lbm) in a pneumatic system is needed
for the first pneumatic device Cylinders can be subject to damage
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DrawbacksA significant weight investment (~10
lbm) in a pneumatic system is needed
for the first pneumatic device Cylinders can be subject to damage
Repair impossible
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DrawbacksA significant weight investment (~10
lbm) in a pneumatic system is needed
for the first pneumatic device Cylinders can be subject to damage
Repair impossible
Not well suited for non-binary actuation
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In Industry
Pneumatic actuators are extensively usedby the Chemical Process Industry due to
their intrinsic safety and their ability to failsafe (w/ spring return)
2-positionpneumatic
actuatordriving a
4-wayball valve
pneumaticallydriven flowcontrol valves(butterfly type)
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How it works
Piston
Cylinder
Seals
NPTF Air Port (Extension)
NPTF Air Port (Retraction)
Rod
Force = Area (in2) x D Pressure (lbf/in2)
Extension Area = Cylinder CS AreaSubtract Rod CS Area for Retraction
Typically,pressureis applied
to one portwhile theother isvented toatmosphere- so DP is
regulatedgaugepressure(60 psi max)
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More works
We may specify Cylinder Diametersets Force @ a pressure
Stroke Length
Mounting Options
Rod Material Rod Extensions
Spring Return
.
Stroke
Length
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Cylinder Specs (Bimba DXP/DX/DP)
Air Pressure (gauge): 60lbf/in2
Length (in)
Nominal Cyl ID Rod OD Extend Retract Extend Retract Base per inch Base
3/4" 0.750 0.250 0.44 0.39 27 24 0.21 0.03 3.75
7/8" 0.875 0.250 0.60 0.55 36 33 0.32 0.03 3.56
1-1/16" 1.063 0.313 0.89 0.81 53 49 0.33 0.05 3.84
1-1/4" 1.250 0.438 1.23 1.08 74 65 0.71 0.08 4.72
1-1/2" 1.500 0.438 1.77 1.62 106 97 0.73 0.08 4.38
1-3/4" 1.750 0.500 2.41 2.21 144 133 1.64 0.11 5.75
2" 2.000 0.500 3.14 2.95 188 177 1.62 0.15 5.62
2-1/2" 2.500 0.500 4.91 4.71 295 283 2.27 0.17 5.623" 3.000 0.625 7.07 6.76 424 406 3.87 0.26 6.50
Dimension (in) Area (in2) Force (lbf) Mass (lbm)
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The pneumatic system I(the investment)
Motor
Compressor
Pressure
Switch
PressureSafetyValveH
igh-Pressure
AirStorage
High-Pressure
AirStorage
Pressure
Gauge
Pressure
Gauge
Pressure
VentValve
Pressure
Regulator
HighPressure
LowP
res
sure
Users
Controller Spike
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The pneumatic system II(the solenoid valve)
Air Supply(Pressure)
Vent B
Vent A
Port A
Port B
A B
V P V
State A
A B
V P V
State B
All ports NPTF
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The pneumatic system III(device control)
SpikeController
AirPressure
A restrictor valve in Vent Bslows extension speed
without affecting retractionspeed
flexible tubing
State AExtends rodState BRetracts rod
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The pneumatic system III(device control)
SpikeController
AirPressure
A restrictor valve in Vent Bslows extension speed
without affecting retractionspeed
flexible tubing
State AExtends rodState BRetracts rod
If you are using pairs ofcylinders which are activatedtogether, they can be drivenby common solenoids
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PlumbingTubing Fittings
Tee - SMC KQT07-00
Male Elbow - SMC KQL07-34S
Male Connector - SMC KQH07-34S
Restrictor Elbow - SMC NAS2201F-N01-07S
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Something outside the box
In 2006
Team 386 created high vacuumwith cylinders
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Team 386 (2006)a better vacuum
Team 386 used suction to lift ringers,but was underwhelmed by the vacuumdeveloped by venturi
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Team 386 (2006)a better vacuum
Retracting the smaller cylinder
Team 386 used suction to lift ringers,but was underwhelmed by the vacuumdeveloped by venturi
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Team 386 (2006)a better vacuum
Retracting the smaller cylinder
Generates a highvacuum on thelarger cylinder
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Team 386 (2006)a better vacuum
Retracting the smaller cylinder
Generates a highvacuum on thelarger cylinder
Separate cylinder sets were used foreach suction cup, providing redundancy
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Team 386 (2006)a better vacuum
Extending the smaller cylinder
Breaks the vacuum
Separate cylinder sets were used foreach suction cup, providing redundancy
Extending the small cylinders releasedthe vacuum and dropped the ringer