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Machine design, tập 84, số 02, 2012

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February 9, 2012 A Penton Media Publication Tune in to EngineeringTV.com ANALYZING TRADEOFFS BETWEEN SERVOS AND STEPPER MOTORS, page 42 TAMING ELECTRICAL NOISE IN MOTION SYSTEMS, page 50 MORE MANUFACTURERS WANT TO “MAKE IT IN AMERICA,” page 64 HOW TO USE THINWALLED BUSHINGS THE RIGHT WAY, page 72                      ŘŎHIƂFLHQF\ Ř&IDFHRU,(&LQSXW Ř37)(VHDOVRQRXWSXWVKDIW ŘVPRRWKERG\PLQLPL]HVSDUWLFOHEDFWHULDFROOHFWLRQ ŘKLJKO\UHVLVWDQWWRPRVWDFLGVDONDOLVDQGFRUURVLRQ    ŘHQFDSVXODWHGVWDWRUHSR[\URWRU ŘUHVLQƂOOHGVWDWRUHQWUDQFH LQVLGHFRQGXLWER[ ŘSDWHQWHGRLOZDWHUUHVLVWDQWEUHDWKHUYHQW    Ř,31(0$;HQFORVXUH Ř6%XV &$1EDVHG FRPPXQLFDWHVZLWK3/& ŘVLQJOHRUWKUHHSKDVHLQSXW RS# 101                             Request a catalog at catalog@ondrives.us See us at www.ondrives.us  30 MACHINE DESIGN.com   FEBRUARY 9, 2012 Wings for Denison: The HS Denison, a 90-ton ocean-going hydrofoil being developed by Grumman Aircraft Engineering Corp for the U S Maritime Administration, was fitted with two 5½-ton main foils A third, sternmounted foil will be fitted later Developed primarily for research purposes, Denison will eventually be put into passenger service between Port Everglades, Fla., and the Bahama Islands She will carry 60 passengers Powered by an 18,000-hp gas turbine, the craft will have a maximum speed of 90 knots MD Try Solid Edge for free! Breakthrough 3D CAD software siemens.com/plm/free-solid-edge Now you can try a fully loaded version of Solid Edge with synchronous technology free with no obligation Experience this state-of-the-art application and discover how the power of synchronous technology can have a significant impact on your engineering productivity, design creativity and product quality This program also includes access to interactive tutorials, video tips and a user forum to help you really experience the power of Solid Edge Download Solid Edge now at siemens.com/plm/freesolid-edge or call 800-807-2200 Solid Edge Design better RS# 124 REPORTER’S NOTEBOOK COMPANY NEWS AWARDS Spirol International Corp., Danielson, Conn., was presented with the 2010 GreenCircle Award by the Connecticut Dept of Energy and Environmental Protection for the creation of the Spirol Nature Conservation area Spirol manufactures engineered components for fastening and joining, including coiled and slotted spring pins, solid pins, disc springs, alignment dowels and bushings, spacers, compression limiters, machined nuts, threaded inserts for plastics, shims, pin and insert installation equipment, and vibratory parts feeders Dr Manfred Wittenstein, president of the Wittenstein Group, Igersheim, Germany, was named “Entrepreneur of the Year” in the “Industry” category during Germany’s prestigious 15th annual “Entrepreneur of the Year” competition Wittenstein produces alpha servodrive components, electromechanical products, and servosystems CERTIFICATION The X20 System from B&R Industrial Automation Corp., Roswell, Ga., has been certified for maritime use by the certification institute Germanischer Lloyd (GL) The X20 System, a complete control and remote I/O system, consists of a bus module, electronics module, and terminal block that allows many different assemblies using a single platform B&R manufactures automation equipment APPOINTMENTS Murata Power Solutions, Mansfield, Mass., has made the following appointments: Bill Smith to the position of Director Product Management for board-mount power products 32 MACHINE DESIGN.com RS# 125 FEBRUARY 9, 2012 PELICAN TM TRUST YOUR TECHNOLOGY TO OURS Mission Critical Custom Case Engineering Harnessing our global resources, Pelican-Hardigg Advanced Case Solutions™ develops custom case solutions using a multidisciplinary process under the industry’s most experienced project management team Driven by your product’s specifications, usage and environmental analysis, these custom case solutions can provide you with the highest level of Mission Critical confidence in the field – guaranteed RS# 126 www.pelicanoem.com/md PELICAN PRODUCTS , INC 23215 Early Avenue, Torrance, CA 90505 866.628.9890 (TOLL FREE) Q 310.326.4700 Q FAX 310.326.3311 All trademarks are registered and/or unregistered trademarks of Pelican Products, Inc., its subsidiaries and/or affiliates REPORTER’S NOTEBOOK COMPANY NEWS (medium to high power dc/dc board-mount line) Lisa Keller, previously the Director of Engineering, is now Director Front End Product and Program Management Mike Schiano takes on the position of Director Planning and Business Development Murata design and manufactures dc/dc converters, ac/dc power supplies, magnetics, data-acquisition devices, and panel meters 3D PRINTING Stratasys, Minneapolis, will begin leasing bundled 3D-printer packages that include the new special edition uPrint 3D printers The uPrint SE 3D Print Pack and the uPrint SE Plus 3D Print Pack are complete 3D-printing packages that include the 3D printer and everything needed to print 3D models For more information, contact Stratasys at info@stratasys.com; (888) 480-3548, or www.stratasys com MEETINGS & SHOWS DESIGN2PART SHOWS SCHEDULE MAGNETIC BRAKING: Lorentz forces result in a braking torque when a magnet is brought into the vicinity of a rotating copper disk Shown are the eddy currents (arrow plot), and electric potential field on the disc and magnet With COMSOL Multiphysics® you are empowered to build simulations that accurately replicate the important characteristics of your designs The key is the ability to include all physical effects that exist in the real world This multiphysics approach delivers results—tangible results that save precious development time and spark innovation comsol.com /showcase © 2012 COMSOL COMSOL and COMSOL Multiphysics are registered trademarks of COMSOL AB Capture the Concept is a trademark of COMSOL AB 34 MACHINE DESIGN.com RS# 127 FEBRUARY 9, 2012 Design-2-Part (D2P) Shows, the largest design and contract manufacturing trade shows in the U S., have released their 2012 show schedule D2P provides design engineers, manufacturing engineers and managers, and purchasers the opportunity to meet local and national job shops and contract manufacturers to source custom parts, components, services, and design The schedule is as follows: Texas D2P Show, Feb 21-22, Gaylord Texan Convention Center, Grapevine, Tex.; Northern California D2P Show, March 21-22, Santa Clara Convention Center, in California; Southeast D2P Show, March 28-29, Cobb Galleria Centre, Atlanta, Ga.; Mid-Atlantic D2P Show, April 11-12, Meadowlands Exposition Center, Secaucus, N J.; Greater Chicago D2P Show, May 1-2, Schaumburg Convention Center, Schaumburg, Ill.; Midwest D2P Show, June 13-14, Saint Charles Convention Center, St Charles, Mo.; Greater Ohio D2P Show, Sept 19-20, John S Knight Center, Akron, Ohio; Southern California D2P Show, Oct 2-3, Long Beach Convention Center, Long Beach, Calif.; Northwest D2P Show, Oct 23-24, Metropolitan Exposition Center, Portland, Oreg.; New England D2P Show, Oct 31 & Nov 1, Royal Plaza Trade Center, Marlborough, Mass.; Southeast D2P Show, and Nov 14-15, State Fair Exposition Center, Raleigh, N C For more information, visit www D2P.com MD Microhydraulics Macro capabilities So much reliability and performance, in so little space Creating high-performance flow control on a micro scale has been The Lee Company’s exclusive focus for more than 50 years And it’s been a successful mission, as evidenced by thousands of applied Lee Microhydraulics designs – ranging from less than 0.10 in to 1.00 in in diameter, and 0.1 to 68 grams, for operating pressures to 8,000 psi But small size and light weight are just the beginning.There’s also absolute reliability built into every Lee component through 100 % testing and inspection Zero defects It’s a production benchmark that has enabled Lee to meet demanding application needs in all sorts of industries Aerospace, medical instrumentation, automotive, machine tools and oil drilling, to name a few The innovative problem solvers We don’t just satisfy requirements We also solve problems – whether by simple modification, or ground-zero design engineering The Lee Company is the world’s most capable and proven source for hydraulic-component innovation And we’ve documented this claim in extensive detail with the Lee Technical Hydraulic Handbook An invaluable reference, the Lee handbook contains essential data on the entire Microhydraulics product line, which includes: Lee Shuttle Valves Detented, spring-biased, inverse, loose ball and zero leak shuttle valves from 50-700 Lohms Lee Safety Screens Best protection for critical system elements 75 to 500 micron hole size Pressures to 7,500 psid Lee Pri Pressure relief valves in insert form 50 to 400 Lohm capacity 20 to 5,400 psid cracking pressures Lee Directional Flow Control 40 to 20,000 Lohms in metered direction 12 to 470 Lohms in free-flow direction Lee Restrictors Single and multi-orifice restrictors 200 to 2.2 million Lohms Lee Plugs The best way to seal drilled holes to 32,000 psi No O-rings, threads or sealants required Lee Cheks All-metal and zero-leak check valves to 400 Lohms Lee Shuttle Valve Shown actual size Designed to isolate the normal from the emergency hydraulic system So small, it fits right into the head of an actuator Innovation in miniature Essential reading for designers of hydraulic systems Send for your free copy The Lee Company Pettipaug Rd, Westbrook CT 06498-0424 860-399-6281 Fax: 860-399-2270 1-800-LEE PLUG www.TheLeeCo.com RS# 128         COMMENTARY Mandating innovation Kenneth J Korane Managing Editor Reliability in a Clutch  % %  % % !  %  % %    %  %  " % % %% "$% %  % %# $%!  !% %%% %  %  % %  " %!%  % "%    % %  %   "%  % !  %%% %%%   %% "! Standard and Custom Clutch, Brake & Power Transmission Solutions 291 Boston Turnpike % Bolton, CT 06043 Phone: 860-643-1531 Been following the cellulosic ethanol fiasco? In a nutshell, Congress passed a law five years ago mandating that oil companies blend cellulosic fuel into gasoline That’s the biofuel made from switchgrass, corn cobs, wood chips, and other plant waste Refiners are supposed to use 500 million gallons this year, and the requirement eventually grows to 16 billion gallons in 2022 Problem is, no one was producing cellulosic fuel outside the lab when the law was passed And despite the government’s insistence and hundreds of millions in subsidies and tax credits, researchers and refiners still haven’t figured out how to make it economically in commercial quantities The EPA recently admitted that less than 0.1% of required renewable fuels will come this year from cellulosic biofuels Yet incredibly, because no cellulosic fuel is available, oil companies must purchase “credits” from the EPA, at about $1.20/gallon, for failing to buy a product that doesn’t exist As the head of the National Petrochemical and Refiners Assn said recently, “This makes no sense.” I say, if the government is going to senselessly mandate the impossible and levy fines for noncompliance, let’s focus on areas that really need attention Baseball strike zone Doesn’t it drive you crazy when a pitch a foot outside is called a strike, then the next one — clearly over the inside corner — is somehow a ball? If the military can plant a cruise missile to within a couple feet of a target a thousand miles away, certainly MLB should be forced to devise a sensor array to tell a ball from a strike Airport security Tired of being herded like cattle, humiliated, stripsearched, and groped? We’re already shelling out $200,000 apiece for security scanners that pose potential health hazards Let’s make the TSA invent a safe, noninvasive way to detect weapons and explosives and apply artificial intelligence to differentiate between someone packing heat and limping with a titanium hip — all while we’re merely walking to our gate without passing through a security gauntlet Flying car Even better than a quick trip through the airport, why not the flying car? In the 60s TV series, The Jetsons, commuting was by cars resembling flying saucers with clear bubble tops Fifty years later, we’re still glued to the ground The government should put the screws to the slackers at Boeing and GM Think of the benefits: Instead of being stuck in traffic, fast commutes would mean less pollution, less stress, higher productivity, and more leisure time Then we could all have George Jetson’s workweek: three hours a day, three days a week Cold fusion Mandates for electric utilities to generate power from wind and solar farms are becoming commonplace How about legislation demanding a portion of the power comes from cold fusion? Though unproven — and likely a scam — who can argue with the economic benefits from cheap and abundant energy, not to mention all the make-work jobs for researchers, scientists, and engineers Have a wish? Write to Congress MD www.cjmco.com 36 RS# 129 MACHINE DESIGN.com FEBRUARY 9, 2012 Tough application, ingenious solution Exactly Mastering challenges together — Rexroth makes it easy to implement automation Our many years’ experience in a wide range of industries has given us extensive application knowledge We offer this comprehensive understanding to the tasks you bring us, leading to ingenious solutions Regardless of the drive technology used, we thought ahead and integrated intelligence throughout This consistency makes you more effi cient — from planning to start-up and daily operation Your benefits are real: Increased productivity, improved energy efficiency and maximum machine safety You can count on Rexroth to have the appropriate drive and control solution to meet your needs exactly Bosch Rexroth Corporation www.boschrexroth-us.com RS# 130 VANTAGE POINT Death knell for lead-acid batteries Dr Peter Harrop In historical terms, the death of the flint tool, cooking by dung, and other bygone technologies occurred rapidly because several factors conspired to bring in better alternatives So it is with lead-acid batteries This huge industry faces an unspectacular future in vehicles — their main use Granted, conventional car and truck sales are still increasing thanks to China and other emerging nations, to around 70 million vehicles annually And there seems to be ongoing use of lead-acid traction-battery power in electric bikes, forklifts, boats, and mobility vehicles for the disabled — say 35 million vehicles yearly However, every month another threat appears that constitutes a serious nail in the coffin for an industry that has served the world well for over 100 years Recent examples include: Stop-start Automatically switching off the engine when a vehicle stops, however briefly, improves fuel efficiency and reduces emissions Thus, the use of this technology is expected to surge in the next few years For urban vehicles with frequent stops, however, lead-acid batteries have difficulty coping, particularly at low temperatures “Microhybrids” seeking to capture and regenerate braking energy compound the problem Lithiumion batteries are, therefore, increasingly preferred Electric vehicles Hybrid-electric vehicles are taking off, particularly industrial and commercial versions Add to that the Toyota Prius, which is expected to exceed million in annual sales within a few years, along with the huge number of new hybrid and pure electric models becoming available Forecasts are for on-road hybrids and EVs with modern batteries to comprise 10 to 20% of global production in 2022 Industrial vehicles Lead-acid batteries in forklifts seem cheap until you look at their poor performance and painfully short life Fuel cells and lithium-ion batteries are coming on for indoor electric industrial vehicles as well as outdoor hybrid forklifts and earthmovers, where lead acid is completely unacceptable E-bikes Almost all electric bicycles have lead-acid batteries today, but nearly all of them are in China Lead acid is almost entirely shunned in other countries because of its heavy weight and poor life and performance Everywhere, bikes are moving from mainly batteryassisted pedaling to so-called e-bikes and scooters with a throttle Lead acid cannot keep up with power demands of these larger two wheelers Tougher pollution laws Worse, an increasing number of Chinese cities are banning or severely restricting 38 MACHINE DESIGN.com FEBRUARY 9, 2012 Chairman IDTechEx Swaffham Bulbeck, Cambridge United Kingdom electric bikes due to accidents, congestion, and improper disposal of lead-acid batteries on more than 100 million electric bikes in use China wants to leapfrog in technology and there is no leapfrogging with lead-acid batteries Concerns over pollution from smelting, manufacture, and disposal are driving the Chinese government to cut leadacid-battery production to 42% of 2010 levels Few of the 1,930 inspected manufacturers will remain and the many unlicensed sites will be sought out and destroyed Outside China, ever tougher emission laws impact everything from tugboats to aircraft Vehicles with lead-acid batteries are increasingly inadequate in addressing those requirements Lower costs Lithium-ion batteries are expensive but their costs will drop by at least two-thirds in the next decade, according to developers, while tiny new range extenders and energy harvesters reduce the size of battery needed Supercapacitors Electrochemical double-layer capacitors have four times the life of rechargeable batteries, tolerate much faster charge-discharge, and use readily available materials Their self-discharge and energy density have been poor but are improving Some now hold a charge for a month and have the energy density of a lead-acid battery Certain electric buses run on supercapacitors alone Indeed, Elon Musk, founder of Tesla electric car company, thinks supercapacitors are the future, not batteries Add in other factors such as the impending use of fuel cells in fleets, battery suppliers and governments focusing their R&D on alternatives, and consumers demanding much better vehicle performance and it’s clear lead-acid batteries will be the losers Investors see the lead-acid battery industry as standing on an escalator going down — faster and faster – even though sales statistics have yet to reflect this Niche markets will remain but clearly, lead-acid batteries are suffering death by a thousand cuts and the end will come more suddenly than most expect MD Battery technology will be a key topic at IDTechEx’s upcoming Electric Vehicle conference (www.IDTechEx.com/evUSA) March 2729 in San Jose Edited by Kenneth J Korane [...]... code or go to: http://machinedesign.com/ article/small-light-rackand-pinion-drive-savesenergy-1208 Engineers should know some gearing basics before specifying gearboxes GEARBOXES 58 Access our Reader Service Web site to quickly find and request information on the products and services 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Subscription Policy: MACHINE DESIGN is circulated to research, development, and design engineers primarily engaged in the design and manufacture of machinery, electrical/electronic equipment, and mechanical equipment To obtain a complimentary subscription see our Web page at submag.com/sub/ mn For change of address fill out a new qualification form at submag.com/sub/mn Printed in U.S.A., Copyright © 2012 Penton... subscription rates: U.S.: one year, $69; two years, $99; Canada/Mexico: one year, $79; two years, $119; All other countries: one year, $99; two years, $149 FEBRUARY 9, 2012 POSTMASTER: Send change of address notice to Customer Service, MACHINE DESIGN, P.O Box 2100, Skokie, IL 60076-7800 Super Ion Air Knife™ Produces a laminar sheet of airÀow that Àoods an area or surface with static eliminating ions Super... and register at http://machinedesign.com Mercedes E-Cell Plus Lee Teschler talks with an engineer from Daimler about the powertrain, NVH, and safety in the Mercedes B-Class E-Cell Plus It has pure-electric range of 70 miles, and a combustion-engine Range Extender permits journeys of up to 500 miles View the episode at www engineeringtv.com/video/MercedesB-Class-E-CELL-PLUS-El ;2012- NAIAS EDITOR’S WEB... See working demos and customer examples February 22, 2012, 2:00 p.m EST CLICK PLC OVERVIEW In this 30-min show, we cover all aspects of the powerful Click micro brick PLC, including hardware features, specifications, expandability, and installation See a demo of the free programming software, and learn where you can download the package March 14, 2012, 2:00 p.m EST Visit www.automationtalk.com to check... one more reason we are likely to see persistent unemployment, and why we shouldn’t expect to soon see headlines about a real boom in blue-collar jobs — Leland Teschler, Editor 8 RS# 107 MACHINE DESIGN.com FEBRUARY 9, 2012 The round thing has to go into the rectangular thing #OMPACT #ENTRIFUGAL -ODULES WITH THE NEW RadiCal IMPELLERS s 3PACE SAVING PACKAGED AIR MOVERS WITH IMPELLER Œ  MM TO ... * Contact us for details MITRPAK Power Transmission Products 38 River Road, Uxbridge, MA 01569     '&   '800-648-7725 www.mitrpak.com 10 MACHINE DESIGN.com 1300 E 9th St Cleveland, OH 44114-1503 FEBRUARY 9, 2012 ...            !" #$%#$%% &'" #$%#$%( RS# 102  %   *     % 1 2)  034( ** 5   + )" 5%  5,  )  + )   ) VOLUME 84 ISSUE 2 FEBRUARY 9, 2012 MOTION CONTROL MOTION CONTROL How Thermograms of a stepper and an equivalent servomotor show a difference in temperature after 10 min of repeatedly executing a move profile lasting a bit less than... $*)*'$$)""$)%#&'(( ''%*)($  11510 Goldcoast Drive*Cincinnati, Ohio*45249-1621*(800) 903-9247*fax: (513) 671-3363 E-mail: techelp@exair.com *www.exair.com @exair www.exair.com/45/470a.htm What’s new online machinedesign.com Free Webcast: February 23, 2:00 p.m EST Today’s additive manufacturing: Injection molding, living hinges, overmolding, and more Objet will discuss advances in rapid prototyping, and how

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