Pneumatics is the branch of mechanics that deals with the mechanical application of gasses. Applications include creating linear actuations through the use of cylinders, creating suction to pick up objects, and even creating rotary motion with certain devices.

What are pneumatics

Mechanisms which use air pressure to apply mechanical force and displacement (work)

The pneumatic devices we use are basically binary actuators either retracted or extended

Retracted Cylinder

Extended Cylinder

What are pneumatics good for?

Mechanisms requiring (2) discrete states

Gear shifters

Gripper articulation

Lifters

Brakes

and a significant force or displacement

Strengths

Simple

Easy to control

Can apply a lot of force from a small, light package

Force is limited by air pressure and cylinder diameter

No adverse consequence if cylinder is stopped (no stalled motors) or reversed compressed air is a spring

In Industry

Pneumatic actuators are extensively used by the Chemical Process Industry due to their intrinsic safety and their ability to fail safe (w/ spring return)

2-position pneumatic

actuator driving a

4-way ball valve

pneumatically driven flow control valves (butterfly type)

C-Rio Computer that controls all devices on robot.

Digital sidecar Provides extra digital and analog inputs and outputs For the C-Rio.

Compressor Provides compressed air for robot Relief valve Relieves pressure over 120 psi for safety.

Manual relief valve Allows for manual relief of pressure when robot is not in use.

Storage tank Up to 4 are used on the robot to store air until it is needed. Depending on their size, less may be used

Pressure sensor Used to tell when the compressor should turn off.

Pressure gauge Gives a visual indication of pressure in the system

Pressure regulator Prevents dangerous pressure levels from being put into the system. Lowers pressure from 120 psi to 60 psi

Brass Fittings Connect Pneumatic tubing to devices such as compressors, tanks, and pistons NOTE: Teflon tape is used to insure a tight connection between threaded fittings. Always leave the first few threads of the fitting free of tape to make it easier to begin tightening the fitting.

Pneumatic piston/ rotary actuator Extends and retracts to move another component of the robot

Solenoid Controls whether a piston is extended or retracted.

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 Area Subtract Rod CS Area for Retraction

Typically, pressure is applied to one port while the other is vented to atmosphere - so DP is regulated gauge pressure (60 psi max)

More works We may specify

Cylinder Diameter sets Force @ a pressure

Stroke Length

Mounting Options

Rod Material

Rod Extensions

Spring Return

.

Stroke

Length

Cylinder Specs (Bimba DXP/DX/DP)

Air Pressure (gauge): 60 lbf/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 5.62

3" 3.000 0.625 7.07 6.76 424 406 3.87 0.26 6.50

Dimension (in) Area (in2) Force (lbf) Mass (lbm)

The pneumatic system I (the investment)

Motor

Compressor

Pressure

Switch

Pressure Safety Valve H

igh-P

ress

ure

Air S

tora

ge

Hig

h-P

ress

ure

Air S

tora

ge

Pressure

Gauge

Pressure

Gauge

Pressure Vent Valve

Pressure

Regulator

Hig

h P

ress

ure

Low

Pre

ssure

Users

Controller Spike

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

The pneumatic system III (device control)

Spike Controller

Air Pressure

A restrictor valve in Vent B slows extension speed without affecting retraction speed

flexible tubing

State A Extends rod State B Retracts rod

The pneumatic system III (device control)

Spike Controller

Air Pressure

A restrictor valve in Vent B slows extension speed without affecting retraction speed

flexible tubing

State A Extends rod State B Retracts rod

If you are using pairs of cylinders which are activated together, they can be driven by common solenoids

Plumbing Tubing Fittings

Tee - SMC KQT07-00

Male Elbow - SMC KQL07-34S

Male Connector - SMC KQH07-34S

Restrictor Elbow - SMC NAS2201F-N01-07S

Something outside the box

Team 386 (2006) a better vacuum

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

Team 386 (2006) a better vacuum

Retracting the smaller cylinder

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

Team 386 (2006) a better vacuum

Retracting the smaller cylinder

Generates a high vacuum on the larger cylinder

Team 386 (2006) a better vacuum

Retracting the smaller cylinder

Generates a high vacuum on the larger cylinder

Separate cylinder sets were used for each suction cup, providing redundancy

Team 386 (2006) a better vacuum

Extending the smaller cylinder

Breaks the vacuum

Separate cylinder sets were used for each suction cup, providing redundancy Extending the small cylinders released the vacuum and dropped the ringer

Pneumatics has applications in just about every industry. From manufacturing, automobile repair, and Dentistry, to robotics, prosthetics, and rollercoasters.