View source for Linear motor

{{Short description|Electric motor that produces a linear force}}
[[File:Linear motor U-tube.svg|thumb|right|225px|[[Free body diagram|Free-body diagram]] of a U-channel synchronous linear motor. The view is perpendicular to the channel axis. The two coils at centre are mechanically connected, and are energized in "[[quadrature phase|quadrature]]" (meaning a phase difference of 90° (π/2 [[radian]]s) between the flux of the magnets and the flux of the coils). The bottom and upper coils in this particular case have a phase difference of 90°, making this a two-phase motor (not to scale).]]
[[File:Linearmotorprinzip.png|thumb|right|Synchronous linear motors are straightened versions of permanent magnet rotor motors.]]

A '''linear motor''' is an [[electric motor]] that has had its [[stator]] and [[rotor (electric)|rotor]] "unrolled", thus, instead of producing a [[torque]] ([[rotation]]), it produces a linear [[force]] along its length. However, linear motors are not necessarily straight. Characteristically, a linear motor's active section has ends, whereas more conventional motors are arranged as a continuous loop.

Linear motors are used by the millions in high accuracy [[computer numerical control|CNC machining]] and in industrial robots. In 2024, this market was USD 1.8 billion.<ref name="VMR">{{cite web |title=Linear Motors Market Size, Share, Trends, Scope & Forecast |url=https://www.verifiedmarketresearch.com/product/linear-motors-market/ |website=Verified Market Research}}</ref><ref name="LinearmotionTips2022">{{cite web |last=Jones |first=Dan |title=Linear motors find a home in CNC machines |url=https://www.linearmotiontips.com/linear-motors-find-a-home-in-cnc-machines/ |website=Linear Motion Tips |publisher=WTWH Media |date=June 20, 2022 |access-date=May 16, 2025}}</ref><ref name="Automate2023">{{cite web |title=Powering Precision: Smart Linear Motors in Industrial Automation |url=https://www.automate.org/motion-control/blogs/powering-precision-smart-linear-motors-in-industrial-automation |website=Automate.org |publisher=Association for Advancing Automation |date=April 3, 2023 |access-date=May 16, 2025}}</ref><ref name="VerifiedMarketResearch2024">{{cite web |title=Linear Motors Market Size and Forecast |url=https://www.verifiedmarketresearch.com/product/linear-motors-market/ |website=Verified Market Research |publisher=Verified Market Research |date=March 2024 |access-date=May 16, 2025}}</ref><ref name="DataInsights2024">{{cite web |title=Global Linear Motor Axes Market – Industry Trends and Forecast to 2032 |url=https://www.datainsightsmarket.com/reports/linear-motor-axes-62429 |website=Data Insights Market |publisher=Data Insights Partner Network |date=February 2024 |access-date=May 16, 2025}}</ref>

A typical mode of operation is as a [[Lorentz force|Lorentz]]-type actuator, in which the applied force is [[linear equation|linearly proportional]] to the [[electric current|current]] and the [[magnetic field]] <math>(\vec F = I \vec L \times \vec B)</math>.

Many designs have been put forward for linear motors, falling into two major categories, low-acceleration and high-acceleration linear motors. Low-acceleration linear motors are suitable for [[maglev train]]s and other ground-based transportation applications. High-acceleration linear motors are normally rather short, and are designed to accelerate an object to a very high speed; for example, see the [[coilgun]].

High-acceleration linear motors are used in studies of [[hypervelocity]] collisions, as [[weapon]]s, or as [[mass driver]]s for [[spacecraft propulsion]].{{citation needed|date=January 2016}} They are usually of the AC [[linear induction motor]] (LIM) design with an active [[three-phase]] winding on one side of the [[Air gap (magnetic)|air-gap]] and a passive conductor plate on the other side. However, the direct current [[homopolar motor|homopolar]] linear motor [[railgun]] is another high acceleration linear motor design. The low-acceleration, high speed and high power motors are usually of the '''linear synchronous motor''' (LSM) design, with an active winding on one side of the air-gap and an array of alternate-pole magnets on the other side. These magnets can be [[permanent magnet]]s or [[electromagnet]]s. The motor for the [[Shanghai maglev train]], for instance, is an LSM.

== Types ==

=== Brushless ===
Brushless linear motors are members of the Synchronous motor family. They are typically used in standard [[linear stage]]s or integrated into custom, [[high performance positioning system]]s. Invented in the late 1980s by [[Anwar Chitayat]] at Anorad Corporation, now [[Rockwell Automation]], and helped improve the throughput and quality of industrial manufacturing processes.<ref>{{cite journal |author=<!--Staff writer(s); no by-line.--> |date= May 18, 1998|title=inear motors come into their own |url= https://www.designnews.com/automation-motion-control/linear-motors-come-their-own|journal= DesignNews}}</ref>

=== Brush ===
[[Brush (electric)|Brushed]] linear motors were used in industrial automation applications prior to the invention of Brushless linear motors. Compared with [[three-phase electric power|three-phase]] brushless motors, which are typically being used today, brush motors operate on a single phase.<ref name=Collins>{{cite journal|last1=Collins|first1=Danielle|title=Are brushed motors suitable for industrial applications?|date=March 15, 2019|url=https://www.linearmotiontips.com/are-brushed-motors-suitable-for-industrial-applications?}}</ref> Brush linear motors have a lower cost since they do not need moving cables or three-phase servo drives. However, they require higher maintenance since their brushes wear out.

=== Synchronous ===
In this design the rate of movement of the magnetic field is controlled, usually electronically, to track the motion of the rotor. For cost reasons synchronous linear motors rarely use [[Commutator (electric)|commutators]], so the rotor often contains permanent magnets, or [[Magnetic core#Soft iron|soft iron]]. Examples include [[coilgun]]s and the motors used on some [[maglev]] systems, as well as many other linear motors. In high precision industrial automation linear motors are typically configured with a magnet stator and a moving coil. A  [[Hall effect sensor]] is attached to the rotor to track the [[magnetic flux]] of the stator. The electric current is typically provided from a stationary [[servo drive]] to the moving coil by a moving cable inside a [[cable carrier]].

=== Induction ===
[[File:Three phase linear induction motor.gif|thumb|A typical 3-phase linear induction motor. An aluminium plate on top often forms the secondary "rotor".]]
{{Main|Linear induction motor}}
In this design, the force is produced by a moving linear [[magnetic field]] acting on conductors in the field. Any conductor, be it a loop, a coil or simply a piece of plate metal, that is placed in this field will have [[eddy current]]s [[electromagnetic induction|induced]] in it thus creating an opposing magnetic field, in accordance with [[Lenz's law]].<ref name=Liasi>{{cite journal|last1=Ghaseminejad Liasi|first1=Sahand|title=What are linear motors?|date=15 May 2015|pages=1–50|doi=10.13140/RG.2.2.16250.18887|url=https://www.researchgate.net/publication/322040360|access-date=24 December 2017}}</ref> The two opposing fields will repel each other, thus creating motion as the magnetic field sweeps through the metal.
{{clear}}

=== Homopolar ===
[[File:Railgun-1.svg|thumb|Railgun schematic]]
{{Main|Railgun}}
In this design a large current is passed through a metal sabot across sliding contacts that are fed by two rails. The magnetic field this generates causes the metal to be projected along the rails.

{{clear}}

=== Tubular ===
{{Main|Tubular linear motor}}
Efficient and compact design applicable to the replacement of [[pneumatic cylinder]]s.

=== Piezoelectric ===
[[File:Piezomotor type inchworm.gif|thumb|right|Piezoelectric motor action]]
{{Main|Piezoelectric motor#Stepping actions}}
[[Piezoelectricity|Piezoelectric]] drive is often used to drive small linear motors.
{{clear}}

== History ==
[[File:Running on the Xunfeng Gang To Hengsha section of Guangzhou Metro Line 6.jpg|thumb|This [[Line 6, Guangzhou Metro|Line 6]] [[Guangzhou Metro]] train manufactured by [[CRRC]] [[Sifang Locomotive and Rolling Stock|Sifang]] and [[Kawasaki Heavy Industries]] propels itself using an aluminium induction strip placed between the rails.]]

=== Low acceleration ===
The history of linear electric motors can be traced back at least as far as the 1840s, to the work of [[Charles Wheatstone]] at [[King's College London]],<ref>{{cite web|url=http://www.kcl.ac.uk/college/history/people/wheatstone.html |title=Charles Wheatstone - College History - King's College London |publisher=Kcl.ac.uk |access-date=2010-03-01 |archive-url=https://web.archive.org/web/20091021162729/http://www.kcl.ac.uk/college/history/people/wheatstone.html |archive-date=2009-10-21 }}</ref> but Wheatstone's model was too inefficient to be practical. A feasible linear induction motor is described in {{US patent|782312}} (1905 - inventor Alfred Zehden of Frankfurt-am-Main), for driving trains or lifts. The German engineer [[Hermann Kemper]] built a working model in 1935.<ref>{{cite web|url=http://cem.colorado.edu/archives/fl1997/thor.html |title=CEM - Fall/Winter 1997 Issue - Germany's Transrapid |access-date=2011-08-24 |archive-url=https://web.archive.org/web/20110928000224/http://cem.colorado.edu/archives/fl1997/thor.html |archive-date=2011-09-28 }}</ref> In the late 1940s, Dr. [[Eric Laithwaite]] of [[University of Manchester|Manchester University]], later Professor of Heavy Electrical Engineering at [[Imperial College]] in [[London]] developed the first full-size working model.

In a single sided version the magnetic repulsion forces the conductor away from the stator, levitating it, and carrying it along in the direction of the moving magnetic field. He called the later versions of it [[magnetic river]]. The technologies would later be applied, in the 1984, [[Air-Rail Link#Maglev|Air-Rail Link]] shuttle, between Birmingham's airport and an adjacent train station.

[[File:Linear Motor of Toei Ōedo Line.jpg|thumb|right|200px|A linear motor for trains running [[Toei Ōedo Line]]]]
Because of these properties, linear motors are often used in [[magnetic levitation|maglev]] propulsion, as in the Japanese [[Linimo]] [[magnetic levitation train]] line near [[Nagoya]]. However, linear motors have been used independently of magnetic levitation, as in the [[Bombardier Innovia Metro]] systems worldwide and a number of modern Japanese subways, including [[Tokyo]]'s [[Toei Ōedo Line]].

Similar technology is also used in some [[roller coaster]]s with modifications but, at present, is still impractical on street running [[tram]]s, although this, in theory, could be done by burying it in a slotted conduit.

Outside of public transportation, vertical linear motors have been proposed as lifting mechanisms in deep [[mining|mine]]s, and the use of linear motors is growing in [[motion control]] applications. They are also often used on sliding doors, such as those of [[low floor]] trams such as the [[Alstom Citadis]] and the [[Socimi Eurotram]]. Dual axis linear motors also exist. These specialized devices have been used to provide direct ''X''-''Y'' motion for precision laser cutting of cloth and sheet metal, automated [[Technical drawing|drafting]], and cable forming. Most linear motors in use are LIM (linear induction motor), or LSM (linear synchronous motor). Linear DC motors are not used due to their higher cost and linear SRM suffers from poor thrust. So for long runs in traction LIM is mostly preferred and for short runs LSM is mostly preferred.

[[File:Linear motor platen surface.jpg|thumb|right|Close-up of the flat passive conductor surface of a motion control
[[Sawyer motor]]
]]

=== High acceleration ===
High-acceleration linear motors have been suggested for a number of uses. They have been considered for use as [[weapon]]s, since current [[armour-piercing]] ammunition tends to consist of small rounds with very high [[kinetic energy]], for which just such motors are suitable. Many amusement park [[launched roller coaster]]s now use linear induction motors to propel the train at a high speed, as an alternative to using a [[lift hill]].

The United States Navy is also using linear induction motors in the [[Electromagnetic Aircraft Launch System]] that will replace traditional [[steam catapult]]s on future aircraft carriers. They have also been suggested for use in [[spacecraft propulsion]]. In this context they are usually called [[mass driver]]s. The simplest way to use mass drivers for spacecraft propulsion would be to build a large mass driver that can accelerate cargo up to [[escape velocity]], though [[reusable launch system|RLV]] launch assist like [[StarTram]] to [[low Earth orbit]] has also been investigated.

High-acceleration linear motors are difficult to design for a number of reasons. They require large amounts of [[energy]] in very short periods of time. One rocket launcher design<ref name="coilgun">{{cite web|url=http://www.coilgun.info/theory/electroguns.htm|title=Magnetic Materials - Electromagnetic Guns|publisher=coilgun.info|access-date=2014-11-22|archive-date=2008-05-16|archive-url=https://web.archive.org/web/20080516063621/http://www.coilgun.info/theory/electroguns.htm}}</ref> calls for 300 GJ for each launch in the space of less than a second. Normal [[electrical generator]]s are not designed for this kind of load, but short-term electrical energy storage methods can be used. [[Capacitor]]s are bulky and expensive but can supply large amounts of energy quickly. [[Homopolar generator]]s can be used to convert the kinetic energy of a [[flywheel]] into electric energy very rapidly. High-acceleration linear motors also require very strong magnetic fields; in fact, the magnetic fields are often too strong to permit the use of [[superconductivity|superconductors]]. However, with careful design, this need not be a major problem.<ref>{{Cite journal|journal = Superconductor Science and Technology|year = 2010|title = A single-sided linear synchronous motor with a high temperature superconducting coil as the excitation system|first1 = F. |last1 = Yen|first2 = J. |last2 = Li|first3 = S. J.|last3 = Zheng|first4 = L.|last4 = Liu|first5 = G. T.|last5 = Ma|first6 = J. S.|last6 = Wang|first7 = S. Y.|last7 = Wang|volume = 23| issue=10 |article-number = 105015|doi = 10.1088/0953-2048/23/10/105015|arxiv = 1010.4775|bibcode = 2010SuScT..23j5015Y| s2cid=119243251 }}</ref>

Two different basic designs have been invented for high-acceleration linear motors: [[railgun]]s and [[coilgun]]s.

== Usage ==
Linear motors are widely used to actuate high-performance industrial automation equipment. Their principal advantage is the ability to deliver any combination of high precision, high velocity, high force, and long travel. Compared to traditional rotary motor and screw-driven systems, linear motors offer direct-drive operation, eliminating backlash and reducing maintenance requirements.<ref name="LinearmotionTips2022"/><ref name="Automate2023"/>

One of the earliest industrial applications of linear motors was in [[loom]]s, where they were used to propel the shuttle rapidly across the weave. In modern settings, linear motors are extensively deployed in [[computer numerical control|CNC]] machines, [[Automated storage and retrieval system|pick-and-place systems]], semiconductor steppers, and high-speed cartesian coordinate robots.<ref name="Laithwaite1957">{{cite journal |last1=Laithwaite |first1=E. R. |last2=Lawrenson |first2=P. J. |title=A self-oscillating induction motor for shuttle propulsion |journal=Proceedings of the IEE - Part A: Power Engineering |volume=104 |issue=2 |pages=65–72 |year=1957 |doi=10.1049/pi-a.1957.0028}}</ref><ref name="LinearmotionTips2022"/><ref name="VerifiedMarketResearch2024"/>

Linear motors are also used in consumer and infrastructure applications. These include powering sliding doors, baggage handling systems, and large-scale bulk materials transport systems such as conveyor belts or transfer carts.<ref name="Automate2023"/>

In large observatory telescopes, such as the European Extremely Large Telescope (ELT), hybrid actuators combining linear motors and piezoelectric elements are employed for precise positioning of mirror segments. These actuators offer high force and nanometer-level precision, essential for maintaining the optical alignment of the telescope's segmented primary mirror.<ref name="PIHybridActuators">{{cite web |title=Different Hybrid Drive Concepts to Solve Tough Positioning and Alignment Tasks |url=https://www.pi-usa.us/en/tech-blog/novel-hybrid-actuators-combine-high-force-nanometer-precision-and-high-dynamics |website=PI USA |access-date=May 17, 2025}}</ref>

Linear motors may also be used as an alternative to conventional chain-run lift hills for roller coasters. The coaster [[Maverick (roller coaster)|Maverick]] at Cedar Point uses one such linear motor in place of a chain lift.

A linear motor has been used to accelerate cars for [[crash test]]s.<ref name="google">{{cite journal|title=Popular Science|journal=The Popular Science Monthly |date=March 1967|publisher=Bonnier Corporation|issn=0161-7370|url=https://archive.org/details/bub_gb_4yADAAAAMBAJ|page=[https://archive.org/details/bub_gb_4yADAAAAMBAJ/page/n65 64]}}</ref>

=== Industrial automation ===
The combination of high precision, high velocity, high force, and long travel makes brushless linear motors attractive for driving industrial automations equipment. They serve industries and applications such as semiconductor [[stepper]]s, electronics [[surface-mount technology]], automotive [[cartesian coordinate robot]]s, aerospace [[chemical milling]], optics [[electron microscope]], healthcare [[laboratory automation]], food and beverage [[pick and place (disambiguation)|pick and place]].<ref name="Automate2023"/>

=== Machine tools ===
Synchronous linear motor [[actuator]]s, used in machine tools and industrial automation, provide high force, high velocity, high precision, and high dynamic stiffness. These characteristics enable zero-backlash motion, low settling time, and exceptional smoothness of movement. Modern systems can achieve velocities of 2&nbsp;m/s or more, with micron-level positioning accuracy and fast cycle times, contributing to superior surface finishes and throughput.<ref name="LinearmotionTips2022"/><ref name="Automate2023"/>

=== Simulation and training devices ===
[https://haptechdefense.com/ Haptech Inc.] uses electromagnetic linear motors in a proprietary application for [https://haptechdefense.com/ military weapons training] that provides high-fidelity & cost-effective instruction to soldiers. [https://www.roadtovr.com/hands-on-striker-vrs-latest-haptic-gun-prototype-brings-a-host-of-improvements/ These motors] provide realistic recoil and other [[Haptic technology|haptic feedback]] to the training devices which enhance the experience while offering precise simulation for training purposes. For their use in military training, these products are the only viable electronic solution that does not force users to adapt to the training device.

=== Train propulsion ===

==== Conventional rails ====
All of the following applications are in [[rapid transit]] and have the active part of the motor in the cars.<ref>{{cite web |url=http://home.inet-osaka.or.jp/~teraoka/old/tera98/ml98edit.htm |title=Adoption of Linear Motor Propulsion System for Subway |publisher=Home.inet-osaka.or.jp |access-date=2010-03-01 |archive-date=2017-08-06 |archive-url=https://web.archive.org/web/20170806055334/http://home.inet-osaka.or.jp/~teraoka/old/tera98/ml98edit.htm }}</ref><ref>{{cite web|title=Linear motor|url=http://www.hitachi.com/csr/highlight/activities/2007/act0701/index.html|archive-url=https://web.archive.org/web/20080708193853/http://www.hitachi.com/csr/highlight/activities/2007/act0701/index.html|archive-date=July 8, 2008}}</ref>

===== Bombardier Innovia Metro =====
{{Main|Bombardier Innovia Metro}}
Originally developed in the late 1970s by [[Urban Transportation Development Corporation|UTDC]] in Canada as the [[Bombardier Innovia Metro|Intermediate Capacity Transit System]] (ICTS). A test track was constructed in [[Millhaven, Ontario]], for extensive testing of prototype cars, after which three lines were constructed:
* [[Line 3 Scarborough]] in Toronto (opened 1985; closed 2023)<ref>{{cite web|date= November 10, 2006 |url=http://transit.toronto.on.ca/subway/5107.shtml |title=The Scarborough Rapid Transit Line – Transit Toronto – Content |publisher=Transit Toronto |access-date=2010-03-01}}</ref>
* [[Expo Line (TransLink)|Expo Line]] of the [[Vancouver SkyTrain]] (opened 1985 and extended in 1994)
* [[Detroit People Mover]] in Detroit (opened 1987)
ICTS was sold to [[Bombardier Transportation]] in 1991 and later known as [[Bombardier Innovia Metro|Advanced Rapid Transit]] (ART) before adopting its current branding in 2011. Since then, several more installations have been made:
* [[Kelana Jaya Line]] in Kuala Lumpur (opened 1998 and extended in 2016)
* [[Millennium Line]] of the Vancouver SkyTrain (opened 2002 and extended in 2016)
* [[AirTrain JFK]] in New York (opened 2003)
* [[Airport Express (Beijing Subway)]] (opened 2008)
* [[Everline]] in Yongin, South Korea (opened 2013)
All Innovia Metro systems use [[third rail]] electrification.

===== Japanese linear metro =====
One of the biggest challenges faced by Japanese railway engineers in the 1970s to the 1980s was the ever increasing construction costs of subways. In response, the Japan Subway Association began studying on the feasibility of the "mini-metro" for meeting urban traffic demand in 1979. In 1981, the Japan Railway Engineering Association studied on the use of [[linear induction motor]]s for such small-profile subways and by 1984 was investigating on the practical applications of linear motors for urban rail with the Japanese [[Ministry of Land, Infrastructure, Transport and Tourism]]. In 1988, a successful demonstration was made with the Limtrain at [[Saitama, Saitama|Saitama]] and influenced the eventual adoption of the linear motor for the [[Nagahori Tsurumi-ryokuchi Line]] in [[Osaka]] and Toei Line 12 (present-day [[Toei Oedo Line]]) in [[Tokyo]].<ref>{{cite web|url=http://www.jametro.or.jp/en/linear/ |title=History of Linear Metro promotion|website=Japan Subway Association}}</ref>

To date, the following subway lines in Japan use linear motors and use [[overhead line]]s for power collection:
* Two [[Osaka Metro]] lines in Osaka:
** [[Nagahori Tsurumi-ryokuchi Line]] (opened 1990)
** [[Imazatosuji Line]] (opened 2006)
* [[Toei Ōedo Line]] in Tokyo (opened 2000)
* [[Kaigan Line]] of the [[Kobe Municipal Subway]] (opened 2001)
* [[Nanakuma Line]] of the [[Fukuoka City Subway]] (opened 2005)
* [[Yokohama Municipal Subway Green Line]] (opened 2008)
* [[Sendai Subway Tōzai Line]] (opened 2015)

In addition, [[Kawasaki Heavy Industries]] has also exported the Linear Metro to the [[Guangzhou Metro]] in China;<ref>{{cite web|url=http://www.urbanrail.net/as/guan/guangzhou.htm |title=> Asia > China > Guangzhou Metro |publisher=UrbanRail.Net |access-date=2010-03-01 |archive-url=https://web.archive.org/web/20100302081742/http://www.urbanrail.net/as/guan/guangzhou.htm |archive-date=2010-03-02 }}</ref> all of the Linear Metro lines in Guangzhou use third rail electrification:
* [[Line 4 (Guangzhou Metro)|Line 4]] (opened 2005)
* [[Line 5 (Guangzhou Metro)|Line 5]] (opened 2009).
* [[Line 6 (Guangzhou Metro)|Line 6]] (opened 2013)

==== Monorail ====
{{Main|Monorail}}
{{More citations needed|date=July 2009}}
* There is at least one known monorail system which is '''not''' magnetically levitated, but nonetheless uses linear motors. This is the [[Moscow Monorail]]. Originally, traditional motors and wheels were to be used. However, it was discovered during test runs that the proposed motors and wheels would fail to provide adequate traction under some conditions, for example, when ice appeared on the rail. Hence, wheels are still used, but the trains use linear motors to accelerate and slow down. This is possibly the only use of such a combination, due to the lack of such requirements for other train systems.
* The [[TELMAGV]] is a prototype of a monorail system that is also not magnetically levitated but uses linear motors.

==== Magnetic levitation ====
{{Main|Maglev (transport)}}
[[File:Birmingham International Maglev.jpg|thumb|The Birmingham International Maglev shuttle]]
* High-speed trains:
** [[Transrapid]]: first commercial use in [[Shanghai Maglev|Shanghai]] (opened in 2004)
** [[SCMaglev]], under construction in Japan (fastest train in the world, planned to open by 2027)
* Rapid transit:
** Birmingham Airport, UK (opened 1984, closed 1995)
** [[M-Bahn]] in Berlin, Germany (opened in 1989, closed in 1991)
** Daejeon EXPO, Korea (ran only 1993)<ref>{{cite web|url=http://maglev.de/index.php?en_korea |title=The International Maglevboard |publisher=Maglev.de |access-date=2010-03-01}}</ref>
** [[High Speed Surface Transport|HSST]]: [[Linimo]] line in Aichi Prefecture, Japan (opened 2005)
** [[Incheon Airport Maglev]] (opened July 2014)
** [[Changsha Maglev Express]] (opened 2016)
** [[S1 line (Beijing Subway)|S1 line]] of [[Beijing Subway]] (opened 2017)

=== Amusement rides ===
{{Main|List of amusement rides}}
There are many roller coasters throughout the world that use LIMs to accelerate the ride vehicles. The first being ''[[Flight of Fear]]'' at [[Kings Island]] and [[Kings Dominion]], both opening in 1996. [[Battlestar Galactica (roller coaster)|Battlestar Galactica: Human VS Cylon]] & [[Revenge of the Mummy]] at [[Universal Studios Singapore]] opened in 2010. They both use LIMs to accelerate from certain point in the rides.

Revenge of the Mummy (located at both [[Universal Studios Hollywood]] and [[Universal Studios Florida]]), [[Hagrid's Magical Creatures Motorbike Adventure]], and [[VelociCoaster]] at [[Universal Islands of Adventure]] use linear motors. At [[Walt Disney World]], [[Rock 'n' Roller Coaster Starring Aerosmith]] at [[Disney's Hollywood Studios]] and [[Guardians of the Galaxy: Cosmic Rewind|''Guardians of the Galaxy'': Cosmic Rewind]] at [[Epcot]] both use LSM to launch their ride vehicles into their indoor ride enclosures.

In 2023 a [[hydraulic launch]] roller coaster, [[Top Thrill Dragster]] at [[Cedar Point]] in Ohio, USA, was renovated and the hydraulic launch replaced with a weaker multi-launch system using LSM, that creates less [[g-force]].

=== Aircraft launching ===
* [[Electromagnetic Aircraft Launch System]]

=== Proposed and research ===
* [[Launch loop]] – A proposed system for launching vehicles into space using a linear motor powered loop
* [[StarTram]] – Concept for a linear motor on extreme scale
* [[Tether propulsion#Tether cable catapult system|Tether cable catapult system]]
* [[Aérotrain|Aérotrain S44]] – A suburban commuter [[hovertrain]] prototype
* [[Research Test Vehicle 31]] – A hovercraft-type vehicle guided by a track
* [[Hyperloop]] – a conceptual high-speed transportation system put forward by entrepreneur Elon Musk
* [[Elevator]] {{cite web|url=http://www.thyssenkrupp-elevator.com/Show-article.104.0.html?&L=1&cHash=08b38cb686f00ec874ad82c44c737427&tx_ttnews=546 |title=ThyssenKrupp Elevator: ThyssenKrupp develops the world's first rope-free elevator system to enable the building industry face the challenges of global urbanization |access-date=2015-06-02 |archive-url=https://web.archive.org/web/20160303215934/http://www.thyssenkrupp-elevator.com/Show-article.104.0.html?&L=1&cHash=08b38cb686f00ec874ad82c44c737427&tx_ttnews=546 |archive-date=2016-03-03 }}
* [[Elevator|Lift]] {{cite web |url=http://www.elevatorworld.com/magazine/synchronous/ |title=Technology: Linear Synchronous Motor Elevators Become a Reality |access-date=2015-06-02 |archive-url=https://web.archive.org/web/20150330081619/http://www.elevatorworld.com/magazine/synchronous/ |archive-date=2015-03-30 }}
* [[Magway Ltd|Magway]] - a UK freight delivery system under research and development that aims to deliver goods in pods via 90&nbsp;cm diameter pipework under and over ground.

== See also ==
{{div col|colwidth=30em}}
* [[Linear actuator]]
* [[Linear induction motor]]
* [[Linear motion]]
* [[Maglev]]
* [[Online Electric Vehicle]]
* [[Reciprocating electric motor]]
* [[Sawyer motor]]
* [[Tubular linear motor]]
{{div col end}}

== References ==
{{Reflist}}

== External links ==
{{commons category|Linear motors}}
* [https://www.instructables.com/id/Electromagnetic-Actuator/?ALLSTEPS Design equations, spreadsheet, and drawings]
* [https://web.archive.org/web/20120324083733/http://www.ms-motor.com/technical-support/motor-torque-calculation Motor torque calculation]
* [https://web.archive.org/web/20080516063621/http://www.coilgun.info/theory/electroguns.htm Overview of Electromagnetic Guns]

{{Electric motor}}

{{Authority control}}

{{DEFAULTSORT:Linear Motor}}
[[Category:Electric motors]]
[[Category:English inventions]]
[[Category:Magnetic propulsion devices| ]]
[[Category:Linear motion]]