A linear motor is an
electric motor
An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate f ...
that has had its
stator and
rotor "unrolled", thus, instead of producing a
torque
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...
(
rotation
Rotation, or spin, is the circular movement of an object around a '' central axis''. A two-dimensional rotating object has only one possible central axis and can rotate in either a clockwise or counterclockwise direction. A three-dimensional ...
), it produces a linear
force
In physics, a force is an influence that can change the motion of an object. A force can cause an object with mass to change its velocity (e.g. moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a ...
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.
A typical mode of operation is as a
Lorentz-type actuator, in which the applied force is
linearly proportional to the
current and the
magnetic field
A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to ...
.
Linear motors are by far most commonly found in high accuracy engineering applications. It is a thriving field of applied research with dedicated scientific conferences and engineering text books.
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 trains 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 typically used in studies of
hypervelocity
Hypervelocity is very high velocity, approximately over 3,000 meters per second (6,700 mph, 11,000 km/h, 10,000 ft/s, or Mach 8.8). In particular, hypervelocity is velocity so high that the strength of materials upon impact is v ...
collisions, as
weapon
A weapon, arm or armament is any implement or device that can be used to deter, threaten, inflict physical damage, harm, or kill. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime, law enforcement, s ...
s, or as
mass drivers for
spacecraft propulsion. They are usually of the AC
linear induction motor (LIM) design with an active
three-phase winding on one side of the air-gap and a passive conductor plate on the other side. However, the direct current
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 magnets or
electromagnet
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into a coil. A current through the wire creates a magnetic field which is concentrated in ...
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 stages or integrated into custom,
high performance positioning systems. Invented in late 1980s by
Anwar Chitayat Anwar Chitayat (born August 21, 1927) is the founder and former CEO and chairman of Anorad Corp., which was acquired in 1998 by Rockwell Automation. Mr. Chitayat holds over 95 patents in Electronics, Semiconductors and Automation including Nanotech ...
at Anorad Corporation, now
Rockwell Automation, and helped improving throughput and quality of industrial manufacturing processes.
Brush
Brush (electric) linear motors were used in industrial automation applications prior to the invention of Brushless linear motors. Compared with
three phase Brushless motors, which are typically being used today, brush motors operates with a single phase.
Brush linear motors have lower cost since they do not need moving cables and 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
commutators
In mathematics, the commutator gives an indication of the extent to which a certain binary operation fails to be commutative. There are different definitions used in group theory and ring theory.
Group theory
The commutator of two elements, ...
, so the rotor often contains permanent magnets, or
soft iron. Examples include
coilguns 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
A Hall effect sensor (or simply Hall sensor) is a type of sensor which detects the presence and magnitude of a magnetic field using the Hall effect. The output voltage of a Hall sensor is directly proportional to the strength of the fiel ...
is attached to the rotor to track the
magnetic flux
In physics, specifically electromagnetism, the magnetic flux through a surface is the surface integral of the normal component of the magnetic field B over that surface. It is usually denoted or . The SI unit of magnetic flux is the weber ...
of the stator. The electrical current is typically provided from a stationary
servo drive
A servo drive is an electronic amplifier used to power electric servomechanisms.
A servo drive monitors the feedback signal from the servomechanism and continually adjusts for deviation from expected behavior.
Function
A servo drive receives a c ...
to the moving coil by a moving cable inside a
cable carrier
Cable carriers, also known as drag chains, energy chains, or cable chains depending on the manufacturer, are guides designed to surround and guide flexible electrical cables and hydraulic or pneumatic hoses connected to moving automated machine ...
.
Induction
In this design, the force is produced by a moving linear
magnetic field
A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to ...
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 currents
induced in it thus creating an opposing magnetic field, in accordance with
Lenz's law.
The two opposing fields will repel each other, thus creating motion as the magnetic field sweeps through the metal.
Homopolar
In this design a large current is passed through a metal sabot across sliding contacts that are fed from two rails. The magnetic field this generates causes the metal to be projected along the rails.
Tubular
Efficient and compact design applicable to replacement of
pneumatic cylinders.
Piezo electric
Piezoelectric drive is often used to drive small linear motors.
History
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
King's College London (informally King's or KCL) is a public research university located in London, England. King's was established by royal charter in 1829 under the patronage of King George IV and the Duke of Wellington. In 1836, King's ...
, but Wheatstone's model was too inefficient to be practical. A feasible linear induction motor is described in the (1905 - inventor Alfred Zehden of Frankfurt-am-Main), for driving trains or lifts. The German engineer
Hermann Kemper built a working model in 1935. In the late 1940s, Dr.
Eric Laithwaite of
Manchester University, later Professor of Heavy Electrical Engineering at
Imperial College
Imperial College London (legally Imperial College of Science, Technology and Medicine) is a public research university in London, United Kingdom. Its history began with Prince Albert, consort of Queen Victoria, who developed his vision for a cu ...
in
London
London is the capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary dow ...
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
The Air-Rail Link is a people mover linking Birmingham Airport with Birmingham International railway station and the National Exhibition Centre in England. The current system, originally known as SkyRail, replaced the earlier Birmingham Maglev s ...
shuttle, between Birmingham's airport and an adjacent train station.
Because of these properties, linear motors are often used in
maglev propulsion, as in the Japanese
Linimo
, formally the is a magnetic levitation train line in Aichi Prefecture, Japan, near the city of Nagoya
is the largest city in the Chūbu region, the fourth-most populous city and third most populous urban area in Japan, with a populatio ...
magnetic levitation train
Maglev (derived from '' magnetic levitation''), is a system of train transportation that uses two sets of electromagnets: one set to repel and push the train up off the track, and another set to move the elevated train ahead, taking advantage ...
line near
Nagoya
is the largest city in the Chūbu region, the fourth-most populous city and third most populous urban area in Japan, with a population of 2.3million in 2020. Located on the Pacific coast in central Honshu, it is the capital and the most po ...
. 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
Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.46 ...
's
Toei Ōedo Line.
Similar technology is also used in some
roller coaster
A roller coaster, or rollercoaster, is a type of amusement ride that employs a form of elevated railroad track designed with tight turns, steep slopes, and sometimes inversions. Passengers ride along the track in open cars, and the rides are ...
s with modifications but, at present, is still impractical on street running
tram
A tram (called a streetcar or trolley in North America) is a rail vehicle that travels on tramway tracks on public urban streets; some include segments on segregated right-of-way. The tramlines or networks operated as public transport ...
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
mines, 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
Accessibility is the design of products, devices, services, vehicles, or environments so as to be usable by people with disabilities. The concept of accessible design and practice of accessible development ensures both "direct access" (i. ...
trams such as the
Alstom Citadis
The Alstom Citadis is a family of low-floor trams and light rail vehicles built by Alstom. , over 2,300 Citadis trams have been sold and 1,800 tramways are in revenue service throughout the world, with operations in all six inhabited continen ...
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
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 higher cost and linear SRM suffers from poor thrust. So for long run in traction LIM is mostly preferred and for short run LSM is mostly preferred.
High acceleration
High-acceleration linear motors have been suggested for a number of uses.
They have been considered for use as
weapon
A weapon, arm or armament is any implement or device that can be used to deter, threaten, inflict physical damage, harm, or kill. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime, law enforcement, s ...
s, since current
armour-piercing ammunition tends to consist of small rounds with very high
kinetic energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acce ...
, for which just such motors are suitable. Many amusement park
launched roller coasters now use linear induction motors to propel the train at a high speed, as an alternative to using a
lift hill
A lift hill, or chain hill, is an upward-sloping section of track on a roller coaster on which the roller coaster train is mechanically lifted to an elevated point or peak in the track. Upon reaching the peak, the train is then propelled from th ...
. The United States Navy is also using linear induction motors in the
Electromagnetic Aircraft Launch System that will replace traditional
steam catapults on future aircraft carriers. They have also been suggested for use in
spacecraft propulsion. In this context they are usually called
mass drivers. 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
RLV launch assist like
StarTram to
low Earth orbit
A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never m ...
has also been investigated.
High-acceleration linear motors are difficult to design for a number of reasons. They require large amounts of
energy
In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of ...
in very short periods of time. One rocket launcher design
calls for 300 GJ for each launch in the space of less than a second. Normal
electrical generator
In electricity generation, a generator is a device that converts motive power ( mechanical energy) or fuel-based power ( chemical energy) into electric power for use in an external circuit. Sources of mechanical energy include steam turbines, ...
s are not designed for this kind of load, but short-term electrical energy storage methods can be used.
Capacitors
A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals.
The effect of a ...
are bulky and expensive but can supply large amounts of energy quickly.
Homopolar generator
A homopolar generator is a DC electrical generator comprising an electrically conductive disc or cylinder rotating in a plane perpendicular to a uniform static magnetic field. A potential difference is created between the center of the disc and t ...
s can be used to convert the kinetic energy of a
flywheel
A flywheel is a mechanical device which uses the conservation of angular momentum to store rotational energy; a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. In particular, as ...
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
superconductors. However, with careful design, this need not be a major problem.
Two different basic designs have been invented for high-acceleration linear motors:
railguns and
coilguns.
Usage
Linear motors are commonly used for actuating high performance industrial automation equipment. Their advantage, unlike any other commonly used actuator, such as
ball screw,
timing belt, or
rack and pinion, is that they provide any combination of high precision, high velocity, high force and long travel.
Linear motors are widely used. One of the major uses of linear motors is for propelling the shuttle in
loom
A loom is a device used to weave cloth and tapestry. The basic purpose of any loom is to hold the warp threads under tension to facilitate the interweaving of the weft threads. The precise shape of the loom and its mechanics may vary, but t ...
s.
Linear motors have been used for sliding doors and various similar actuators. Also, they have been used for baggage handing and even large-scale bulk materials transport.
Linear motors are sometimes used to create rotary motion, for example, they have been used at observatories to deal with the large radius of curvature.
Linear motors may also be used as an alternative to conventional chain-run lift hills for roller coasters. The coaster
Maverick
Maverick, Maveric or Maverik may refer to:
History
* Maverick (animal), an unbranded range animal, derived from U.S. cattleman Samuel Maverick
Aviation
* AEA Maverick, an Australian single-seat sportsplane design
* General Aviation Design Bure ...
at Cedar Point uses one such linear motor in place of a chain lift.
A linear motor has been used for accelerating cars for
crash tests.
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
steppers, electronics
surface-mount technology, automotive
cartesian coordinate robots, aerospace
chemical milling, optics
electron microscope
An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a hi ...
, healthcare
laboratory automation, food and beverage
pick and place.
Machine tools
Synchronous linear motor
actuator
An actuator is a component of a machine that is responsible for moving and controlling a mechanism or system, for example by opening a valve. In simple terms, it is a "mover".
An actuator requires a control device (controlled by control signal) a ...
s, used in machine tools, provide high force, high velocity, high precision and high dynamic stiffness, resulting in high smoothness of motion and low settling time. They may reach velocities of 2 m/s and micron-level accuracies, at short cycle times and a smooth surface finish.
Train propulsion
Conventional rails
All of the following applications are in
rapid transit
Rapid transit or mass rapid transit (MRT), also known as heavy rail or metro, is a type of high-capacity public transport generally found in urban areas. A rapid transit system that primarily or traditionally runs below the surface may be ...
and have the active part of the motor in the cars.
= Bombardier Innovia Metro
=
Originally developed in the late 1970s by
UTDC in Canada as the
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)
*
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
Bombardier Transportation was a Canadian-German rolling stock and rail transport manufacturer, headquartered in Berlin, Germany.
It was one of the world's largest companies in the rail vehicle and equipment manufacturing and servicing industry ...
in 1991 and later known as
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
A third rail, also known as a live rail, electric rail or conductor rail, is a method of providing electric power to a railway locomotive or train, through a semi-continuous rigid conductor placed alongside or between the rails of a railway ...
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 motors 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 and influenced the eventual adoption of the linear motor for the
Nagahori Tsurumi-ryokuchi Line in
Osaka
is a designated city in the Kansai region of Honshu in Japan. It is the capital of and most populous city in Osaka Prefecture, and the third most populous city in Japan, following Special wards of Tokyo and Yokohama. With a population of ...
and Toei Line 12 (present-day
Toei Oedo Line) in
Tokyo
Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.46 ...
.
To date, the following subway lines in Japan use linear motors and use
overhead line
An overhead line or overhead wire is an electrical cable that is used to transmit electrical energy to electric locomotives, trolleybuses or trams. It is known variously as:
* Overhead catenary
* Overhead contact system (OCS)
* Overhead equipm ...
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
The is a rapid transit system in Kobe, Hyōgo Prefecture, Japan. Like other large Japanese cities, Kobe's subway system is heavily complemented by suburban rail. In addition, two people mover lines also serve the Kobe area: the Port Island Line ...
(opened 2001)
*
Nanakuma Line
The is a subway line, part of the Fukuoka City Subway system in Fukuoka, Japan. It runs from Hashimoto Station in Nishi Ward to Tenjin-Minami Station in Chūō Ward, all within Fukuoka. The line's color on maps is green. Officially, the lin ...
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
(or simply Kawasaki) is a Japanese Public company, public multinational corporation manufacturer of motorcycles, engines, Heavy equipment (construction), heavy equipment, aerospace and Military, defense equipment, rolling stock and ships, headq ...
has also exported the Linear Metro to the
Guangzhou Metro
The Guangzhou Metro () ( and ) is the rapid transit system of the city of Guangzhou in Guangdong Province of China. It is operated by the state-owned Guangzhou Metro Corporation and was the fourth metro system to be built in mainland China, af ...
in China; all of the Linear Metro lines in Guangzhou use third rail electrification:
*
Line 4 (opened 2005)
*
Line 5 (opened 2009).
*
Line 6 (opened 2013)
Monorail
* 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
* High-speed trains:
**
Transrapid: first commercial use in
Shanghai
Shanghai (; , , Standard Chinese, Standard Mandarin pronunciation: ) is one of the four Direct-administered municipalities of China, direct-administered municipalities of the China, People's Republic of China (PRC). The city is located on the ...
(opened in 2004)
**
SCMaglev
The SCMaglev (superconducting maglev, formerly called the MLU) is a magnetic levitation ( maglev) railway system developed by Central Japan Railway Company (JR Central) and the Railway Technical Research Institute.
On 21 April 2015, a manned s ...
, 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)
**
HSST:
Linimo
, formally the is a magnetic levitation train line in Aichi Prefecture, Japan, near the city of Nagoya
is the largest city in the Chūbu region, the fourth-most populous city and third most populous urban area in Japan, with a populatio ...
line in Aichi Prefecture, Japan (opened 2005)
**
Incheon Airport Maglev (opened July 2014)
**
Changsha Maglev Express
The Changsha Maglev Express () is a medium-low speed magnetic levitation, or '' maglev'' line in Changsha, China. This is China's second maglev line, after Shanghai Maglev, and the first domestically built maglev line that uses indigenous tech ...
(opened 2016)
**
S1 line of
Beijing Subway
The Beijing Subway is the rapid transit system of Beijing Municipality that consists of 25 lines including 20 rapid transit lines, two airport rail links, one maglev line and 2 light rail lines, and 463 stations. The rail network extends ...
(opened 2017)
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 Galctica: Human VS Cylon &
Revenge of the Mummy at
Universal Studios Singapore
Universal Studios Singapore (abbreviation: USS) is a theme park located within the Resorts World Sentosa at Sentosa, Singapore. It features 28 rides, shows, and attractions in seven themed zones. It is one of the six Universal Studios theme ...
opened in 2010. They both use LIMs to accelerate from certain point in the rides.
Revenge of the Mummy also is located at
Universal Studios Hollywood and
Universal Studios Florida.
The Incredible Hulk Coaster and
VelociCoaster
VelociCoaster (marketed as Jurassic World VelociCoaster) is a launched roller coaster at Universal's Islands of Adventure in Orlando, Florida. Manufactured by Intamin and themed to the Velociraptors from the ''Jurassic World'' film franchise, th ...
at
Universal's Islands of Adventure also uses linear motors. At
Walt Disney World
The Walt Disney World Resort, also called Walt Disney World or Disney World, is an entertainment resort complex in Bay Lake and Lake Buena Vista, Florida, United States, near the cities of Orlando and Kissimmee. Opened on October 1, 1971, ...
,
Rock 'n' Roller Coaster Starring Aerosmith
Rock 'n' Roller Coaster Starring Aerosmith is an enclosed, launched roller coaster located at Disney's Hollywood Studios within Walt Disney World. Manufactured by Vekoma, the roller coaster opened to the public on July 29, 1999. It uses linear ...
at
Disney's Hollywood Studios and
''Guardians of the Galaxy'': Cosmic Rewind at
Epcot
Epcot, stylized in all uppercase as EPCOT, is a theme park at the Walt Disney World Resort in Bay Lake, Florida. It is owned and operated by The Walt Disney Company through its Parks, Experiences and Products division. Inspired by an unre ...
both use LSM to launch their ride vehicles into their indoor ride enclosures.
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 cable catapult system
*
Aérotrain S44 – A suburban commuter
hovertrain
A hovertrain is a type of high-speed train that replaces conventional steel wheels with hovercraft lift pads, and the conventional railway bed with a paved road-like surface, known as the ''track'' or ''guideway''. The concept aims to eliminate ...
prototype
*
Research Test Vehicle 31
Research is " creative and systematic work undertaken to increase the stock of knowledge". It involves the collection, organization and analysis of evidence to increase understanding of a topic, characterized by a particular attentiveness ...
– A hovercraft-type vehicle guided by a track
*
Hyperloop – a conceptual high-speed transportation system put forward by entrepreneur Elon Musk
*
Elevator
An elevator or lift is a cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or decks of a building, vessel, or other structure. They ...
*
Lift
*
Magway - a UK freight delivery system under research and development that aims to deliver goods in pods via 90 cm diameter pipework under and over ground.
See also
*
Linear actuator
*
Linear induction motor
*
Linear motion
*
Maglev
*
Online Electric Vehicle
*
Reciprocating electric motor
A reciprocating electric motor is a motor in which the armature moves back and forth rather than circularly. Early electric motors were sometimes of the reciprocating type, such as those made by Daniel Davis in the 1840s. Today, reciprocating elect ...
*
Sawyer motor A Sawyer motor or planar motor (also called area drive) is a multi-coordinate drive that can perform several independent movements in one plane. Goods can be transported along any path to any location. In the industrial environment, the planar moto ...
*
Tubular linear motor A tubular linear motor is a type of linear electric motor with a forcer consisting of a series of solenoids wrapped around a cylinder enclosing a movable rod that contains a number of strong cylindrical permanent magnets aligned in alternating and ...
References
External links
Design equations, spreadsheet, and drawingsMotor torque calculation
{{DEFAULTSORT:Linear Motor
Electric motors
English inventions
Linear motion