Machine Design Moving Toward Eco-Friendly Hydraulic Fluid

THE IMPORTANCE OF
CUSTOM PARTS p. 20
A SMARTER WAY
TO SPECIFY
COMPOSITES p. 44
SIZING MOTORS FOR
LINEAR MOTION p. 50
AUGUST 15, 2013
machinedesign.com

BY ENGINEERS FOR ENGINEERS

Moving Toward Eco-friendly

HYDRAULIC
FLUID
37

p|

A Penton® Publication


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AUGUST 15, 2013 | VOLUME 85, ISSUE 10

In This Issue
FEATURES
37

MAKING THE MOVE TO ECO-FRIENDLY HYDRAULIC FLUIDS
Biodegradable hydraulic fluids are safer for the environment than petroleumbased fluids, but they require special design considerations.

44

37

HOW TO AVOID OVERENGINEERING COMPOSITE PARTS
Analysis techniques help avoid a tendency for
designers to overengineer composite parts.

50

HOW TO PICK MOTORS FOR LINEAR MOTION
The easiest way to design a linear-motion system is to add components
one by one. Then, step-by-step calculations relate input to power
dissipated moving a load in a specific amount of time.

60

44

FORCE SENSORS AND THEIR USES
Force sensors use load cells to weigh objects and
prevent machinery from overloading.

NEWS
20

ENGINEERS &
CUSTOM COMPONENTS:
A reader survey

DEPARTMENTS
4
ON MACHINEDESIGN.COM
10
LETTERS
12
WHAT’S INSIDE

Eco-friendly Hydraulic
Shock Absorbers

50
COLUMNS
6
EDITORIAL
End-of-life blues
16

COMMENTARY
Fracking: It’s Better Than the
Alternatives

34

INTERVIEW
The Changing Role of System
Integrators — Tom Price

64

GOLDENSE ON R&DPRODUCT DEVELOPMENT
Innovation-enabling Tools and
Software for Individuals
and Product Pipelines

A Bearing Built for
Wind Turbines
33

SENSOR SENSE
Encoders for safety

80

PUZZLES, MYTHS,
AND CURIOSITIES

PRODUCTS
65
PRODUCT SPOTLIGHTS
Fluid-Power Cylinders & Valves
CAD
68
77
78
78

NEW PRODUCTS
DATA FILES
CLASSIFIEDS
AD INDEX

ON THE COVER: Photo illustration: Tony Vitolo

60
2

ISSN 0024-9114

Printed in U.S.A., Copyright © 2013. Penton Media, Inc. All rights reserved. MACHINE DESIGN is published semimonthly except for a single issue in January, February, April, June, July, August, and October by
Penton Media, Inc., 9800 Metcalf Ave., Overland Park, KS 66212.
Paid subscriptions include issues 1-16. Issue No. 17 (OEM Handbook and Supplier Directory) is available at additional cost. Rates: U.S.: one year, $139; two years, $199;. Canada/Mexico: one year, $159; two
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POSTMASTER: Send change of address notice to Customer Service, MACHINE DESIGN, P.O. Box 2100, Skokie, IL 60076-7800.

08.15.13

MACHINE DESIGN


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ENHANCING MEDICAL-DEVICE
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AUGUST 27, 2013 AT 2:00 P.M. ET
This presentation will acquaint medical-device designers with
the metal injection-molding (MIM) manufacturing process and
its capabilities. Presented by the Metal Injection Molding
Assn., the Webinar will walk viewers through examples and
case studies of successful applications of the technology.
Get more details and register at />learning-resources/webinars.

EDITOR’S WEB PICKS

ACCESS HARDWARE
Southco has a new Web site (www.southco.com) in eight languages on its access hardware, including latches, hinges, handles,
and locks. Users can find product info and compliance certificates, download CAD files and catalogs, and request samples.

HEATER CATALOG
Watlow’s new Heating Solutions catalog covers electric
industrial heaters, sensors, and controllers. Content includes
product specs and drawings, and a selection matrix that helps

users match heater type and application. Get a copy in various
formats at www.watlow.com.

TEST & MEASUREMENT
Agilent Technologies’ Faculty Spotlight Web site features universities throughout the world using the company’s electronic
test and measurement instrumentation in unique applications,
new curriculum, research, and novel projects. Find it at www.
agilent.com/find/facultyspotlight.

4

Google’s new glasses are shaking up the concept of interconnectivity. They let the wearer capture images and shoot videos,
search for info, and translate foreign languages – all handsfree. Electronic Design Editor Bill Wong talks to app developer and CEO of Pepperdeck.com and Glass Tesla about the
underlying technology. View the episode at www.engineeringtv.com/video/A-Look-at-Google-Glass.

join us online
TYPES OF PRESSURE
Turck has released a new white paper, “Types of Pressure:
When and Why Are They Used?” It explain how good measurement practices are essential
in industrial and process automation, but there are different ways
to interpret measurements. The
white paper discusses different
types of measurements, when and
why they are used, and highlights
how they suit various applications. Download a copy at www.
askturck.com.

BEARING SELECTOR
The Kaydon Bearings Web site, www.kaydonbearings.com,
now has an interactive bearing selector. Users search by details

such as bore size, OD, and width and results include applicable
products and 2D and 3D drawing downloads. Results can be
refined using Kaydon’s engineering software, which analyzes
loads and calculates basic life and safe operating speeds.

08.15.13

MACHINE DESIGN


The Secret To Keeping Electronics Cool!
NEMA 12
Cabinet Coolers

A bad choice could cost you thousands!

The NEMA 12 Cabinet
Coolers for large heat
loads up to 5,600 Btu/
hr. are ideal for PLCs, line
control cabinets, CCTV
cameras, modular control
centers, etc.

Look Familiar?
When hot weather causes the electronics inside
a control cabinet to fail, there is a panic to get
the machinery up and running again. The
operator might choose to simply open the
panel door and aim a fan at the circuit boards.

In reality, the fan ends up blowing a lot of
hot, humid, dirty air at the electronics and the
cooling effect is minimal. If the machinery
starts functioning again, the likelihood of
repeated failure is great since the environment
is still hot (and threatens permanent damage
to the circuit boards). Worse yet, that open
panel door is an OSHA violation that presents
a shock hazard to personnel.

• Measures 8" (203mm) high
• Mounts top, side or bottom
• Enclosure remains dust-tight
and oil-tight

NEMA 4 and 4X
Cabinet Coolers

NEMA 4 and 4X Cabinet
Coolers for large heat loads
up to 5,600 Btu/hr. They
are ideal for PLCs and
modular controls.
• Enclosure remains dusttight, oil-tight and splash
resistant
• Suitable for wet locations
where coolant spray or hose
down can occur

Type 316 Stainless Steel

Cabinet Coolers

Type 316 Stainless Steel
Cabinet Coolers for
NEMA 4X applications are
available for heat loads up
to 5,600 Btu/hr.
• Resists harsh environments
not suitable for Type 303/304
• Ideal for food and chemical
processing, pharmaceutical,
foundries, heat treating
and other corrosive
environments

Mini NEMA 12, 4, and
4X Cabinet Coolers

The mini NEMA 12, 4
and 4X Cabinet Coolers
for small heat loads up
to 550 Btu/hr. are ideal
for control panels, relay
boxes, laser housings,
and electronic scales.
• Measures 5" (127mm) high
• Mounts top, side or bottom
• Enclosure remains dusttight and oil-tight

The Real Solution!

Stop electronic downtime with an EXAIR
Cabinet Cooler® System! The complete line of
low cost Cabinet Cooler Systems are in stock
and can ship now. They mount in minutes
through an ordinary electrical knockout and
have no moving parts to wear out. Thermostat
control to minimize compressed air use is
available for all models. All Cabinet Coolers are
UL Listed to US and Canadian safety standards.

Allow us to
“Size It Up”

Cabinet Cooler
SIZING GUIDE
www.exair.com/45/m_szg.htm

The only compressed air powered
cooler that is CE compliant!
High Temperature
Cabinet Coolers

Non-Hazardous Purge
Cabinet Coolers

High Temperature Cabinet
Coolers for NEMA 12, 4
and 4X applications are
available for heat loads
in many capacities up to

5,600 Btu/hr.

NHP Cabinet Coolers keep
a slight positive pressure on
the enclosure to keep dirt
from entering through small
holes or conduits. For use in
non-hazardous locations.

• Suitable for ambients up to
200°F (93°C)

• Uses only 1 SCFM in
purge mode

• Ideal for mounting near
ovens, furnaces, and other
hot locations

• For heat loads up to 5,600
Btu/hr.
• NEMA 12, 4 and 4X

If you would like to discuss an application, contact:

“It took us three days to get a replacement computer cabinet and we didn’t
want to risk another heat failure. Fans weren’t an option since they would
just blow around a lot of hot air. Freon-type air conditioners like those on
some of our other machines were a constant maintenance project of their
own. We purchased EXAIR’s Model 4330 NEMA 12 Cabinet Cooler

Jeff Hauck, Lasercraft Inc. Cincinnati OH

System since it was easy to install and requires no maintenance.”

11510 Goldcoast Drive
Cincinnati, Ohio 45249-1621
(800) 903-9247/fax: (513) 671-3363

www.exair.com/45/440b.htm
@exair


Editorial
LELAND TESCHLER | Editor


End-of-life
blues
e’d occasionally find someone’s garbage dumped on the side
of the road back when I was growing up. That was illegal,
so we’d call the cops about it. They’d happily come out and
sort through the stuff because invariably, the dumpers were
stupid enough to leave their junk mail, complete with an address, in the discarded
trash. The scofflaws would then get a visit from a state trooper who would hand
them a citation and a stiff fine.
I bring this up because there is an intensifying debate about who should be responsible for the disposal of packaging. Economists are starting to think that a system that
gives that responsibility to manufacturers makes more sense than foisting the problem off on cities and states. They argue that such a scheme would bring some sanity to
the idea of which materials are worth recycling and which are just garbage.
One problem with the existing state of affairs is that both landfills and recycling
programs are subsidized, so it is almost impossible to figure out the real economics

of either disposal method. For example, landfill space is priced below the full economic cost of landfilling partly to discourage the kind of illegal dumping I saw as a
kid. Recycling programs typically get priced so their promoters can claim putting
plastic bottles in colored recycling bins is cheaper than throwing them in a landfill.
But it’s hard to really know the truth of that statement when the price of both landfill
space and recycling programs are distorted.
One economist who has studied these price distortions is Duke University professor Michael C. Munger. He points out that because it is almost impossible to know the
“real” price of landfills and recycling efforts, many of the arguments for recycling have
taken a religious tone: Putting garbage in a landfill is no longer expensive; it’s evil.
This sort of attitude can lead to zany outcomes. Munger recounts an incident
during a North Carolina drought a few years ago when Duke switched to disposable
paper dishes, napkins, and utensils in its food-service operations. The idea was to
save water, which had become more expensive than the landfill space occupied by
low-quality, hard-to-recycle eating supplies. “It would have been irresponsible, in
terms of the opportunity cost of the resources, to continue to use water as if it were
plentiful,” he says.
But that didn’t matter to a lot of students and faculty at Duke. Munger says students and faculty both complained that is was wrong to dispose of waste in a landfill.
He says he asked at least 20 people why landfilling the stuff was wrong but could
never get an answer. They just knew that is was, he says.
That takes us back to the concept of making end-of-life issues the problem of
manufacturers. Such a mandate would be an extra headache for designers of products and packaging, who would be forced into figuring out the end-of-life economics of the materials they used. But it would make discussions about garbage less
theological.

6

08.15.13

MACHINE DESIGN


The round thing has to go

into the rectangular thing.

These space-saving centrifugal module packages include our new RadiCal
impeller design for the best aerodynamic efficiency and acoustics. The
square packages range in size from 6.5” (165mm) to 11.8” (300mm) with
performance up to 940 CFM or 3” static pressure. Modules are ‘plug and
play’, can be mounted in any orientation and are completely maintenancefree. Available with PSC motors or energy efficient Green-Tech EC motors
in 2-speed or fully speed controllable versions. For more information,
visit info.ebmpapst.us/RadiCal.

The engineer’s choice


AUGUST | 2013
EDITORIAL
EDITOR IN CHIEF: LELAND TESCHLER
MANAGING EDITOR: KENNETH J. KORANE
SENIOR EDITORS: ELISABETH EITEL
STEPHEN J. MRAZ
ASSOCIATE EDITOR: LINDSEY FRICK
EDITORIAL PRODUCTION MANAGER: DENISE GRECO
ART DIRECTOR: RANDALL L. RUBENKING

INDUSTRY COVERAGE:
AUTOMOTIVE, PACKAGING, MEDICAL STEPHEN J. MRAZ
CAD/CAM, MANUFACTURING ELISABETH EITEL, LINDSEY FRICK
FASTENING & JOINING, MATERIALS LINDSEY FRICK
FLUID POWER KENNETH J. KORANE
MECHANICAL ELISABETH EITEL, LINDSEY FRICK, KENNETH J. KORANE

ART DEPARTMENT
CREATIVE DIRECTOR: DIMITRIOS BASTAS
GROUP DESIGN DIRECTOR: ANTHONY VITOLO

PRODUCTION
GROUP PRODUCTION DIRECTOR: CAREY SWEETEN
PRODUCTION COORDINATOR: COURTNEY DENISON

AUDIENCE MARKETING
AUDIENCE MARKETING MANAGER: BRENDA ROODE
AUDIENCE DEVELOPEMENT MANAGER: DEBBIE BRADY

ONLINE
ONLINE SALES & MARKETING MANAGER: VIRGINIA GOULDING
CLIENT SERVICES COORDINATOR: JOANN MARTIN

SALES & MARKETING
BRAND DIRECTOR: PAUL MILNAMOW T | 312.840.8462
REGIONAL SALES REPRESENTATIVES
AZ, CA, ID, OR, NV, UT, WA, BRITISH COLUMBIA: PAUL MILNAMOW,
T | 312.840.8462 F | 913.514.3957
AL, AR, FL, GA, KS, LA, NM, MS, MO, OK, TX: FRANNY SINGLETON
T | 678.947.8563 F | 913.514.6884
CO, IA, S. IN, KY MN MT, NE, ND, S. OH, SD, TN, WI, WV, WY: PAUL MILNAMOW
T | 312.840.8462 F | 913.514.3957
IL: MELINDA HURLEY T | 847.784.9825 F | 913.514.6625
N. IN, N. OH, MI, NY, PA, Ontario: BILL RODMAN T | 216.931.9636 F | 913.514.6841
DE, DC, MD, NJ, NC, SC, VA: BRANDY BISSELL T | 919.773.1875 F | 913.514.6357
CT, ME, NH, MA, RI, VT, QUEBEC: LIZ STOTT, T | 857.636.9737 F | 913.514.6914
INTERNATIONAL SALES REPRESENTATIVES

International Sales Director: MIKE HANCOCK,
T | 011.44.1372.824284 F | 011.44.1372.824322
UNITED KINGDOM, SCANDINAVIA, FRANCE, SPAIN, PORTUGAL: STUART PAYNE
T | +44 0)1932 564999 F | +44 0)1932 564998
Belgium, Netherlands, Luxemburg: RODRIC LEERLING
T | 011.31.229.841882 M | 31.683.232625
Germany, Austria, and Switzerland: CHRISTIAN HOELSCHER,
T | 011.49.89.95002778 F | 011.49.89.95002779
Italy: CESARE CASIRAGHI Casiraghi Pubblicitá Estera T | 011.390.31.261407 F | 011.390.31.261380
Tokyo, Japan: YOSHINORI IKEDA Pacific Business, Inc. T | 011.81.03.3661.6138 F | 011.81.03.3661.6139

DESIGN ENGINEERING & SOURCING GROUP
VICE PRESIDENT & MARKET LEADER: BILL BAUMANN
GROUP DIRECTOR OF EDITORIAL CONTENT: NANCY FRIEDRICH
GROUP DIRECTOR OF OPERATIONS: CHRISTINA CAVANO
GROUP DIRECTOR OF MARKETING: JANE COOPER
RESEARCH MANAGER: JULIE RITCHIE
MARKETING & EVENTS SPECIALIST: ADRIAN PIAZZA
MARKETING COMMUNICATIONS SPECIALIST: CYNTHIA RODRIGUEZ

PENTON MEDIA INC.
CHIEF EXECUTIVE OFFICER: DAVID KIESELSTEIN
CHIEF FINANCIAL OFFICER: NICOLA ALLAIS
SENIOR VP, DESIGN ENGINEERING GROUP: BOB MACARTHUR
1166 AVENUE OF THE AMERICAS, 10TH FLOOR
NEW YORK, NY 10036 T | 212.204.4200

Electronic Design | Machine Design | Microwaves & RF | Medical Design | Source ESB | Hydraulics & Pneumatics | Global Purchasing | Distribution Resource | Power
Electronic | Mobile Dev & Design | Defense Electronics | Auto Electronics | Electronic Design Europe | Engineering TV

08.15.13

MACHINE DESIGN


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Letters
WILL THEY STEP FORWARD?
One of the biggest problems I found
with the new generation of automation

engineers and techs is their lack of initiative (“Seven Ways Older Automation
Experts Can Help the Industry,”by John
Rinaldi, Jun. 3). Although many of us
have decades of experience under our
belt, we leave an industry that still relies
on old technology. New engineers have
a hard time incorporating or adapting
the old with the new.
New engineers just don’t have the
drive and rely too much on computers instead of good old creativity or
problem-solving ability. If, or when, we
arrive at a major change in technology,
there will be an explosion of technology that should surpass anything we
have available at the moment. The
entire manufacturing sector will have
to change and those who don’t will be
left behind.
That’s when our young engineers will
have an opportunity to shine and prove
they can accomplish far better advancements than those on who’s foundation
they stood before they started to climb
the ladder.
Joaquin Cardena

EPA COMES CLEAN
The miles-per-gallon of any particular
vehicle is an extraordinarily difficult
parameter to measure because there
are so many variables. Brooks Lyman
(Letters, May 23) listed several, but

there are more, including air temperature and wind speed, even altitude.
I drove an ’85 Chevy Sprint (Suzuki
Swift) for 10 years and consistently
got 50 mpg with a daily 72-mile commute (round trip). The engine was a
three-cylinder, four-stroke one-liter
design. And I was no slouch speedwise. Tires lasted 75,000 miles, brakes
85,000. At 110,000 miles I gave it to a
friend who was ecstatic and said that
the government should buy them for
poorer folks to reduce air pollution.
Where are they now?
Robert H. Russell

10

NEW ENGINE AND
GAS MILEAGE
One reader noticed the difference
between new and older engineers
and hopes the newer ones are up
to the challenge when they become
the ones in charge. Other readers are
troubled that the EPA doesn’t account for
E85 gas in mileage ratings.

Just finished reading the letters regarding mileage and the EPA. I drive a
1999 Corvette with a 350-hp engine,
aftermarket exhaust, K&N air filter, and
six-speed transmission. The car’s EPA
numbers were about 19/26 mpg on the

sticker. Funny thing about EPA numbers is that they are usually not correct.
Also, most people believe you should
have a small car with a small engine to
get good numbers.
On the round trips between our home
in Connecticut and our vacation home
in Florida, my average mileage, while
driving as fast as traffic allows (around
80 mph most of the time with plenty of
jack-rabbit starts), is about 30 mpg. This
is both the calculated number and that
shown on the car’s trip computer. I put
in 87 octane gas (with 10% ethylene)
unless it is really hot. Then I buy 89 or
93. Most people with similar Corvettes
get about the same mileage or more with
conservative driving.
What is the magic? How about
good aero design, low weight, and
high horsepower and torque taking
advantage of good overdrive ratios?
At 72 mph, my engine turns at about
1,500 rpm, which is exactly twice the
engine’s idle speed.
Let’s figure out how to do the same
on some of the boring “high-mileage
econoboxes” many people feel they
need to drive to get fuel economy.
Imagine how much could be accomplished without ethanol. And how
about some of the very economical

European diesel engines?
Robert Bubello

Believe it or not, the EPA must be
listening to the public for once. A
recent check at shows that some newer vehicles now have fuel-economy ratings
based upon standard gasoline and on
E85. The vehicle I was interested in
suffers a 25% reduction in economy
when E85 is used instead of gasoline.
I guess I’ll be looking even more
closely at getting one of the new crop
of diesel-powered vehicles because
the mileage should definitely be better and the fuel cost is generally less
than 10% higher. As for the up-front
diesel powerplant cost, I can recoup
that at resale.
Duane Levine

ROOM FOR A CREW?
Looking at the crew module specs for
NASA’s Orion capsule (NASA’s Orion
Goes International, Apr. 11), it says
the return payload is only 220 lb. Is
this a one-man capsule?
Howard Chin
No, NASA does not include crew
weight, or that of the fuel and breathing gasses among other things, in the
payload weight.

LETTERS TO THE EDITOR:
Please include your name, address, and daytime phone number. Letters may be edited for
brevity and to focus on essential points.
Mail: Letters, MACHINE DESIGN, 1300 E. 9th St.,
Cleveland, OH 44114-1503, Fax: 216-621-8469
E-mail, Editorial:

08.15.13

MACHINE DESIGN



What’s Inside

Eco-friendly Hydraulic
Shock Absorbers

Oil

THE ECO SERIES of hydraulic shock absorbers from ITT Enidine Inc., Orchard Park,
N. Y. (www.enidine.com), can handle a wide range of forces and moving masses,
absorbing maximum energy within a compact envelope. The shock absorbers use
materials and fluids that are considered safe for the environment. For example, the
device, along with all the coatings, comply with RoHS. The hydraulic oil it uses is
Orifices
biodegradable. And even the packaging materials used for shipping the shock
absorbers can be recycled.
The shocks, which all come with a jam nut, are available in adjustable and
nonadjustable versions, and have an Enicote II finish which protects against

corrosion and is rated at 350 hr of saltwater protection. The nonadjustable
Piston
shocks are also tamperproof. Threaded cylinders give users flexibility in
head
mounting the shocks and also increases the surface area for better heat
dissipation. The devices can also mount into pressure chambers.
The shocks have strokes that range from 0.25 to 1.0 in. and can
withstand 25 to 930 in.-lb/cycle, or 55,000 to 682,000 in.-lb/hr.
The devices weigh from 0.5 to 10.5 oz and handle reaction forces
from 200 to 1,250 lb. They operate in temperatures from 15 to
180°F, but this can be extended with optional fluids and seals
to –30 to 210°F. There are also food-grade versions of the
ECO shock absorbers.
Edited by Stephen J. Mraz

More power from less energy
Machine tools with built-in
efficiency
Your machine tools will be extremely
cost-effective with HAWE‘s efficient
and reliable hydraulic solutions.
Find out more at www.haweusa.com.

Hydraulic Power Pack KA

Coil
spring

Check
ring

Foam
accumulator

Cylinder

Piston rod

Shock
tube

Bearing


Smarter Embedded Designs,
Faster Deployment

The combination of NI LabVIEW system design software and reconfigurable I/O
(RIO) hardware helps small design teams with varied expertise develop demanding
embedded applications in less time. Using this graphical system design approach,
you can take advantage of the same integrated platform to program embedded
processors and FPGAs for faster application development in industries ranging
from energy to transportation, manufacturing, and life sciences.

>> Accelerate your productivity at ni.com/embedded-platform

800 453 6202
©2013 National Instruments. All rights reserved. LabVIEW, National Instruments, NI, and ni.com are trademarks of National Instruments.
Other product and company names listed are trademarks or trade names of their respective companies. 12118

LabVIEW system design
software offers ultimate
flexibility through FPGA
programming, simplifies
code reuse, and helps
you program the way you
think–graphically.


What’s Inside

A Bearing Built for
Wind Turbines
THE NAUTILUS BEARING from SKF USA Inc.,

High-friction
coating
minimizes
movement
between mating
components

Single-pocket, segmented
PEEK cage increases loadcarrying capability.

Combined seals
Landsdale, Pa. (www.skf.com/us), is a double-row
and carriers
tapered bearing set that is compact and used in
reduce risks of

wind turbines to carry all rotor loads, forces, and
contamination
and reduces
moments. Up to now, most large turbines used
weight and costs
two bearing sets to handle axial and radial loads
separately. Using only one bearing means only
rotor torque gets transmitted to the drivetrain and
that weight and cost are reduced. The two rows of
tapered bearings are arranged back to back and lock
the unit axially, so it delivers high levels of stiffness.
The bearing is also more compact than the
Pregreased
two bearings traditionally used. This makes for a
bearing
smaller, lighter, and less-costly nacelle. And the
eliminates
contamination
large number of rolling elements makes for extreme
precision between raceways, so the unit can
carry high loads. The Nautilus bearing is, in fact,
designed for multimegawatt turbines — and those
Bolted inner
ring for
turbines can be directly driven or have gearboxes,
safety and
have outer or inner-ring rotation, and be mounted
reliability
Corrosion protection in vulnerable areas
on shafts or bolted onto the surrounding structure.

The bearing uses an Ecopur polyurethane seal
that is held in place by built-in carriers. The seal can be replaced
to the rotor hub and the mainframe. This eliminates any
on top of the turbine, simplifying maintenance. Seals and grease
effects of excessive tolerances between the bearing and the
help prevent corrosion, a constant threat for offshore turbines.
surrounding structure, including the shaft, housing, and lock
The bearing comes standard with a bolted outer ring. A
ring. It also reduces variations in preload during operation.
Edited by Stephen J. Mraz
bolted inner ring is optional, which lets the bearing be attached

Types of pressure:
when and why are
they used?
©2013 TURCK

askTURCK.com


Schaeffler, with our INA and FAG brands, has set a standard that is unrivaled
throughout the industry by offering innovative products and unmatched support services that can dramatically improve the performance and reliability
of pumps used in wastewater, dewatering and petrochemical applications.
Here’s why this is no idle boast:
Innovative Products
Schaeffler’s latest generation of double-row angular contact bearings in
X-life™ quality generate less friction, put less stress on lubricants and enable lower operating temperatures. Thanks to higher ball quality, improved
raceway surfaces and more precise dimensional and running tolerances, the
bearing’s internal friction is significantly reduced. As a result, higher speeds
or longer bearing operating life can be achieved. So reliability goes up, and

energy consumption goes down.
Groundbreaking Technology
X-life is Schaeffler’s designation for premium products from our INA and FAG
brands that offer engineers completely new design perspectives. Thanks
to superfinished raceway surfaces that ensure smooth, uniform running
characteristics, maximum load-carrying capacity and superior rigidity, the
operating life of X-life bearings is considerably longer than standard bearings
under identical operating conditions. Alternatively, higher loads can now be
applied while maintaining the same rating life values.
Unmatched Engineering Support
The industry’s most comprehensive suite of calculation software, BEARINX®
is Schaeffler’s cutting-edge program for performing rolling bearing and
linear guidance system calculations. One of our latest modules, BEARINXonline “Easy Friction” enables customers - free-of-charge - to calculate all of the
friction forces at the discrete points of the contact surfaces inside the bearing.
When it comes to bearings for your pumps, don’t just go with the flow.
Go with Schaeffler.
Need more details?
Please contact us at ads.ind@schaeffler.com
www.schaeffler.us
©2013

Superior-quality products.
Comprehensive reliable solutions.


Commentary
STEPHEN J. MRAZ


Fracking:

It’s Better Than
the Alternatives

H

ydraulic fracturing, a method of getting more
natural gas out of shale formations, has been a
major boon for the U. S. and the rest of the world.
It lets the U. S. get 40% of its gas from shale, a
once little-regarded resource. It has pushed the price of natural
gas from $13/ft3 in 2008 to under $4/ft3 today. This translates
into annual savings of $1,000 in heating and electricity costs per
household, with most of these savings going to those who aren’t
rich. And fracking means fewer U. S. dollars go overseas.

Like any industrial process — including steel making,
egg farming, and solar power and wind turbines — fracking can lead to problems if done improperly or negligently.
But no responsible person advocates letting companies act
negligently or illegally. In fact, gas companies want to make
fracking safe for both humans and the environment. These
firms are also working with local, state, and federal governments to establish meaningful guidelines and legislation. At
the same time, local governments want the taxes, landowners want the royalties, consumers want the lower energy
prices, and everyone wants a clean planet.
In fact, the EPA has been looking at fracking and has
found few problems. One issue it investigated was methane
supposedly leaking into water supplies due to fracking. An
EPA study found that so-called contaminated wells “contained levels of methane typical in the area and below levels
that the federal government considers a threat to health.”
Then in 2011, the head of the EPA testified to Congress that
she was “not aware of any proven case where the fracking

process itself affected water… In no case have we made a definitive determination that the fracking process has caused
chemicals to enter groundwater.”
So deciding between fracking or the environment looks
like a false choice. We can have both. Fracking has already
produced enough natural gas to send U. S. coal-generated
electricity from 48 to 37% of U. S. needs in only four years.
It has also convinced utilities not to build about 150 new
coal-fired plants. Many are planning natural-gas burning
plants instead. These new plants will release none of the soot,

16

mercury, arsenic, or lead that come from coal-burning generators and half the CO2. Meanwhile natural gas from fracking has been partly responsible for the U. S. cutting its CO2
emissions by 800 million tons since 2007, a better cleanup act
than all those countries that signed onto the Kyoto Protocols.
Coal isn’t the only energy soured that has problems. As
John Hanger, a former secretary of the Pennsylvania Dept.
of Environmental Protection, said in a recent article (http://
www.guardian.co.uk/commentisfree/2013/jul/08/shale-gasfracking-good-for-environment) for The Guardian:
“Virtually all of our energy choices have big safety and
environmental risks or significant weaknesses. There is no
perfect or excellent energy source that has no environmental impact, is low cost, and operates continuously. Indeed,
especially in terms of the environment, our energy choices
today are mostly ugly.”
Nuclear energy, for example, leaves us with hazardous
wastes which we can’t figure out how to dispose of. And
most U. S. residents have a fear, perhaps irrational, of radioactivity. (I wonder how many citizens know they get dosed
with relatively high levels of radiation every time they fly.)
Oil can be dangerous to transport, difficult to clean up
after spills, and burning it releases lots of CO2, along with

other toxic substances and soot.
Hydroelectric dams disrupt river life and tick off the
Sierra Club. Corn-based ethanol distorts the corn markets,
leaving some people hungry, and has been known to harm
engines and fuel systems. Wind and solar power will take a
long time to scale up to where they provide more than 5% of
our power. Plus, neither can generate a single watt if it’s too
windy or not windy enough at night. And if we did build
enough solar panels and wind turbines, who’s to say all those
non-reflective surfaces and impediments to the wind won’t
affect weather patterns and climate?
Fracking and the burning of natural gas might not be
perfect, but they sure seem to be better than the alternatives.
Let’s work to make it safer and more affordable with prudent
and fairly enforced safety and environmental regulations.

08.15.13

MACHINE DESIGN


Sense-ability.

Newark element14 makes it easy to find all of your sensors and transducers – fast. newark.com


Smart Machines

FREQUENTLY ASKED QUESTIONS

WHAT IS A SMART MACHINE?
Smart machines today are generally
those that must be able to operate
somewhat autonomously and must
be able to adapt to changing conditions. For the most part, they handle
tasks that are not solely repetitive.
Smart machines must also be able
to avoid and correct process errors
and learn from those situations
to avoid difficulties in the future.
Smart machines also typically
provide information to a higher level
control system that facilitates
smarter operations in general.
HOW HAS THE SMART
MACHINE CONCEPT CHANGED
MACHINE DESIGN?
Traditional computer-controlled
machines combined a machine
controller, a local HMI such as an
operator terminal, and connectivity
to a plant automation network. In
contrast, smart machines tend to
have modular architectures that make
use of off-the-shelf systems such as
robots to speed development. They
also integrate additional embedded
control and monitoring systems to
distribute processing. Consequently,
there has been a shift toward

software-centric design approaches

Sponsored by National Instruments

and programming tools that let
designers use one software design
tool for multiple tasks as a means of
handling increased system complexity.
WHAT COMPONENTS TYPICALLY
GO INTO A SMART MACHINE?
Smart machines are aware of
processes through use of a comprehensive network of sensors. These
sensors collect information about
machine conditions and the status
of ongoing processes. The resulting
measurements are typically used to let
the controller monitor the condition
and performance of the machine. The
sensor network is extensive enough
to let the controller gather enough
information to
decide whether to
initiate maintenance
or even automatically apply different
control settings
to the system.
Smart machines
also require a highperformance network of embedded
systems to implement advanced

control strategies
and complex control
algorithms. The trend is
to integrate monitoring
and control into one
hardware system. This
approach can have
economic advantages
and may boost the
performance of the
automation equipment
as well. Finally, machine
builders often rely on
an additional system
that is added to the
machine controller and performs the
monitoring task independent from
the machine control system. The
two systems generally communicate
via standard industrial I/O lines.
HOW ARE SMART
MACHINES DEFINED?
Smart machines usually are built
around distributed control architectures that dedicate one electric
motor to controlling each axis.
This is in contrast to using cams,
gear trains, and other mechanical
linkages to power individual axes
from one central motor. Machine
builders need to adopt a softwarecentric approach to deal with

the resulting complexity, usually
through software development
tools that provide both simulation
and deployment capabilities. They
let machine designers simulate
dynamic systems, design controllers,
and deploy control systems to the
hardware that will actually run the
system. These development systems
generally include an analysis
palette in the time and frequency
domains. Control programs that
use adaptive and model-based


A

control strategies typically can be
deployed straight from simulations.
WHY IS THE SMART MACHINE
CONCEPT IMPORTANT FOR
MOTION CONTROL?
Decentralized control works with
the trend away from using a central
motor to power individual axes
through gears trains, cams, and other
mechanical linkages. Now individual
motors typically power specific axes
and are synchronized in software.
This approach reduces the cost and

weight of the machine and makes
the mechanical system more flexible.
The resulting machines can also be
modular and more easily expanded.
There is also a trend toward more
axes and much more complex motion
profiles and control algorithms.
Mechanical systems that deviate from
the classical XYZ axis setup require
complex control algorithms to transform the movement of the end effector
into the movement of individual joints.
Machine designers tend to need access
to low-level motor control algorithms
to implement the commands necessary
to realize these sorts of movements.
Ditto for implementing adaptive
control algorithms. Only a few machine
builders feel comfortable customizing low-level motor control routines
without the help of their tool providers.
HOW DO FPGAS FIT INTO SMART
MACHINE DESIGN?
FPGAs are the primary enabling
technology for parallel control. The
reason is FPGAs execute multiple tasks
simultaneously. They are highly reliable because they implement control
schemes using only hardware logic.
There is no overhead of an operating
system or interactions with multiple
software routines to worry about.
FPGAs once were used only by engineers with a high level understanding

of hardware circuit design who could
program FPGAs in VHDL (VHSIC
hardware description language).
This is no longer the case as now,
software tools can convert block
diagrams of control schemes into
plans for programming FPGA circuitry.
Software packages are now available which give access to control
functions through high-level programming interfaces but if necessary,
let the builder get at machine-level
code to customize lower level IP,
often through changes in an FPGA.

D

V

E

R

T

I

S

E

M

E

N

T

National Instrument’s
Control Design Guide
for

Next-Generation
Machines

The Control Design Guide for
Next-Generation Machines
explains the challenges machine
builders face today and
demonstrates proven methods
and solutions to get ahead of
the competition. Experience the
impact graphical system design
and customizable off-the-shelf
hardware has on the design
process and business success.
Download the guide at

QLFRPFRQWUROGHVLJQJXLGH

ENGINEERS &
CUSTOM COMPONENTS
A reader survey

M

HOW OFTEN DO YOU USE CUSTOM
COMPONENTS IN YOUR DESIGNS?

achine Design surveyed some of its readers to
better understand how engineers use custom
components. Results show 85% of engineers rely on custom parts, which have a median price of about $500. And
while many designers specify low-cost custom items like
fasteners, switches, and connectors, others spec in custom motor and power supplies, as well as structural parts
and machined subassemblies.

Never
17%

Once every
two months
31%

Once every
two years 7%

Stephen Mraz,

A vast majority of
designers (85%)

rely on custom
parts, and over half

Once a year
17%

Less than $200
17%

7%
Less than $20
Less than $5
2%

Less than $500
14%

designs at least

Every six months
28%

HOW MUCH DOES YOUR COMPANY
SPEND ON EACH CUSTOM
COMPONENT (AVERAGE)?

Less than $50
14%

(59%) use them in

every six months.

WHAT FACTORS WOULD MAKE YOU
MORE LIKELY TO SPECIFY CUSTOM
COMPONENTS?
43% Lower prices

More than $1,000
27%

32% Easier ordering process

Less than $1,000
18%

46% Faster delivery times
42% Better technical help in configuring custom components
37% A guarantee on quality, price, and delivery times

Custom parts can range from specialty wash-

0

10

20

30

40

ers to oversized tires for limited-production
off-road equipment, and prices vary accord-

Companies that want to sell more custom parts should

ingly. Our survey shows that prices do indeed

work on lowering prices, speeding delivery, making

vary widely when it comes to the custom parts

ordering more simple, and then guaranteeing it all.

engineers specify for their designs, with the
median being about $500.

20

08.15.13 MACHINE DESIGN