Pneumatic Components & Systems 2008

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


Force is limited by air pressure and cylinder

diameter


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Strengths Simple

Easy to control


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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for the first pneumatic device Cylinders can be subject to damage


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Repair impossible


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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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Retracting the smaller cylinder

Team 386 used suction to lift ringers,but was underwhelmed by the vacuumdeveloped by venturi


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Generates a highvacuum on thelarger cylinder


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Generates a highvacuum on thelarger cylinder

Separate cylinder sets were used foreach suction cup, providing redundancy


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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

Pneumatic Components & Systems 2008

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