New sexy LSMs all over the place?

[aceospades1250]

Hey everyone, I'm really curious about these new LSM launches that are popping up all over the place. I'm talking about the thin, white fins that are on iSpeed, Maverick, Sky Rocket, etc. I understand how LSMs work in general, but does anyone know specifically how these motors work? I was under the impression that LSMs were large electromagnets like the ones on Superman The Escape, which pull the train away from the previous motor then switch polarity to push it towards the next.

 

I'm curious as to how the mechanics of the newer ultra-slim versions work, since I can't see how such powerful electromagnets are crammed into such a small space. Are they contained underneath the tracks?

 

Thanks!

[Tmcdllr]

This should help...

 

Linear Induction Motor

A Linear Induction Motor (LIM) is a non-contacting, high speed, linear motor that operates on the same principal as a rotary, squirrel cage, induction motor. They are capable of speeds up to 1800 in/sec [45 m/s] and are typically used in applications where accurate positioning is not required. LIM’s can also be operated at stall to produce static thrust

 

The 3-phase coil assembly can be directly connected to the AC line for single speed applications or to an adjustable frequency drive for precise variable control of the speed of the motor. The motors are reversible and can also be dynamically braked.

 

The laminated coil assembly (shown above) is used in conjunction with a customer supplied aluminum and steel reaction plate to produce a force. A customer supplied bearing system is required to maintain the .040” - .060” [1 – 1.5 mm] air gap between the coil assembly and the reaction plate. The length of the reaction plate is equal to the coil length plus the stroke.

 

The amount of thrust produced by the LIM is proportional to the active surface area of the motor.

 

There is an attractive force between the coil assembly and the steel in the reaction plate only when power is applied to the coil assembly.

 

Multiple coil assemblies can used together to produce larger forces.

 

If the reaction plate is a disc, then rotary motion can be produced.

 

Either the LIM or the reaction plate can move while the other is fixed.

 

In hostile environments a non-magnetic stainless steel barrier can be used between coil assembly and the reaction plate to provide a seal.

 

Advantages:

 

* Only 2 parts

* Wide speed range

* No Maintenance

* Non-contact

* Ease of Control and Installation

 

Applications:

 

* Conveying Systems

* Cranes Drives

* Baggage Handling

* Vision Inspection Equipment

* Personal Rapid Transport Systems

* Theme Park Rides

 

The LIM consists of 2 main components

 

* 3 Phase Coil Assembly: The coil assembly is comprised of a 3-phase winding that is wound and inserted into a steel lamination stack with thermal protection devices. The entire assembly is then encapsulated with thermally conductive epoxy. Steel Angles with mounting holes are provided for mounting the coil assembly to the customers system. The coil assembly is available in many different widths and lengths, to meet the customers force and packaging requirements. The coil assembly can be used in a single sided or double-sided configuration. The single sided configuration consists of a single coil assembly that is used in conjunction with an aluminum plate backed by a steel reaction plate. The double-sided configuration is where 2 coil assemblies are facing each other, separated by a gap of .25” [6 mm] and only an aluminum reaction plate passes thru the gap. Multiple coil assemblies can be used together to produce larger forces. The standard sizes for the coil assemblies are shown on the following page.

* Reaction Plate: The customer supplied reaction plate is required for proper operation of the LIM. The reaction plate is made up of standard, readily available 1018 steel, aluminum, and / or copper. For single sided operation, the required reaction plate consists of a .125” [3 mm] thick aluminum or a .080” [2 mm] thick copper plate that is backed by a .25” [6 mm] thick ferrous steel plate. The steel plate can be omitted but the force will be dramatically reduced. For double-sided operation only a conductive plate of copper or aluminum is required.

Required Electronics:

A 3-phase AC voltage directly from the line, an adjustable frequency supply, or a vector drive can be used to drive the LIM. The LIMs can be supplied for single phase AC, but the result is a less efficient motor. All standard voltages are available; 220, 380, 400, 415, 460, 600 @ 50 / 60 Hz

The speed of the LIM is proportional to the input frequency (which can be variable) and the pole pitch of the lamination stack (which is fixed). Connecting directly to the AC line at 50 or 60 Hz will produce a constant linear speed. Using an adjustable frequency drive (or inverter) will allow speeds as slow as 6 in/sec [0.15 m/s] and as fast as 1800 in/sec [45 m/s] at 400 Hz.

 

Linear Synchronous Motor

LSMs generate propulsive force by running current through a stator, which creates an electro-magnetic field. This electro-magnetic field interacts with a set of permanent magnets on a vehicle to create thrust. The permanent magnets serve as the motor secondary, equivalent to a rotor in conventional motors enabling linear motion. The vehicle is propelled by the moving electro-magnetic field, traveling along as electric current is applied to the stator beneath the vehicle. The vehicle’s movement is regulated by a sophisticated control system incorporating state-of-the-art position sensing technology.

 

Linear Synchronous Motors (LSMs) can be used anywhere that you need linear motion or actuation. Factory automation applications using chain- and belt-based conveyor systems, hydraulic actuators, and lead screw drives are a few examples where LSMs could produce the required action, serving as an alternative to these mechanically dependent devices. Advantages include the following:

 

* Increase reliability

o Fewer components subject to wear

o Acceleration and braking not dependent on friction

* Improve performance

o Increased speed, acceleration, efficiency

o Provide more precise position control

* Negotiate steep grades without depending on friction

o Any slope is possible, including vertical

* Eliminate the need to have propulsion power and control on the vehicle

o Vehicle can be passive

* Ability to control multiple vehicles on complex trajectories

o No need to transfer communication or control signals to a moving vehicle

 

Major improvements in LSM technology over the last decade have made electro-magnetic propulsion a more viable solution for manufacturing and transportation industries. LSMs now use better and less expensive power electronic components and faster and more versatile digital signal processors with motor control features. Our motor configurations have been optimized using more advanced research and design tools. LSMs are well suited to many types of industrial applications. Permanent magnets (specifically NdFeB magnets) have also become less expensive, and have a higher electro-magnetic energy product.

 

LSM systems can be designed and implemented to deliver a wide range of performance. High-thrust systems like those developed for maglev trains can reach speeds up to 166 m/s (360 mph). Lifting force generated by heavy industrial LSM elevator systems can lift up to 3.1 meganewtons (700,000lbs-force), the force needed to lift an elevator platform and fighter jet on an aircraft carrier. Positioning accuracy can reach better than one micrometer, as required in the semiconductor industry. Power generated for maglev systems can reach up to 40 MW.

 

As demands have increased in the manufacturing industries for higher speeds and more precise factory automation control, developments in LSM technology at MagneMotion have kept pace. Replacing an outdated conventional conveyor system with LSM propulsion can greatly increase throughput and decrease downtime and energy usage, in turn reducing the overall costs of operation and production. MagneMotion’s LSM designs focus on scalable modular solutions tailored to individual applications, to accommodate industrial equipment design and a wide range of manufacturing processes. Accurate control, logic, power electronics, position sensing, and communication are integrated in the LSM modules, creating a simpler system that reduces the need for third-party products, simplifying the systems integration effort. The control system is developed to provide a high degree of flexibility in system operation so thrust, positioning, and traffic management remain almost unchanged when the LSM-based design is scaled up or down. Please see our control systems page for more information.

 

Factory automation, packaging, and material handling

 

* Manufacturing facilities, product assembly, cleanrooms, distribution centers, hazardous materials processing and transport

o Faster and more efficient process automation

o Lower maintenance

o Motors can be mounted outside a glove box or enclosure

o Lower energy requirements

o Fewer moving parts

o Reduced IO (Input/Output)

 

Elevator Applications

 

* Passenger elevators for tall buildings, Military elevators for weapons and aircraft

o Lighter than conventional elevators and use less space (smaller footprint)

o Multiple cabs in a single shaft

o Potential for one-way travel: up one hoistway and down another one

o Higher speed and fewer hoistways for a given performance

 

Heavy Industrial LSM Solutions

 

* Mining diagonal and vertical solutions

o Lift for deep vertical mine shaft or for hauling ore up a steep slope

o Eliminates the need for cables and counterweights

o No height limit due to cable weight

o Can be much faster than cable-hoist elevators

o Cost effective and much higher capacity process

* Replace hydraulic actuators in industrial equipment

o No fluid leaks or hydraulic assembly reliability problems

o No need for hydraulic pressure control systems

* Swing motor for large shovels and drag line machines

o Replace several large motors driving a bull-ring gear

o Higher reliability, higher speed, better control

 

Transportation Applications

 

* Vehicle propulsion

o Propel wheeled and maglev vehicles

o Acceleration and braking not dependent on friction

o Control system entirely on guideway; no communication of critical information required by the vehicle

o Can tailor peak force to vehicle needs

o Allows use of small vehicles with short headway; decreased waiting time

* Can assist conventional locomotives on steep grades

* Maglev propulsion

o Electro-magnetic suspension, guidance, and propulsion with single magnetic structure

o More effective, efficient electro-magnetic suspension

 

Military/Navy Applications

 

* Shipboard elevators

o Substantial weight savings and reduced maintenance as compared with existing hydraulic and cable-drawn mechanisms

o Replace hydraulics in same sized space

o Actuators on submarines and surface ships

o Higher reliability, lower maintenance due to more accurate control and elimination of wearing parts

* Automated material handling

o Both horizontal and vertical movement under automatic control

o Systems for loading and unloading ships

o Hazardous cargo handling

* Aircraft and vehicle launch and arrest

o Manned and unmanned aircraft

o Torpedoes and countermeasures

 

 

While these may not be exactly what is used on most rollercoasters, the explanations and principles of operation are similar.

 

While on the subject of these new technologies, you might as well include magnetic braking too. Unfortunately it's from Wikipedia.

 

Eddy Current Brakes

Linear eddy current brake

 

The principle of the linear eddy current brake has been described by the French physicist Foucault, hence in French the eddy current brake is called the "frein à courants de Foucault".

 

The linear eddy current brake consists of a magnetic yoke with electrical coils positioned along the rail, which are being magnetized alternating as south and north magnetic poles. This magnet does not touch the rail, as with the magnetic brake, but is held at a constant small distance from the rail (approximately seven millimeters). It does not move along the rail, exerting only a vertical pull on the rail.

 

When the magnet is moved along the rail, it generates a non-stationary magnetic field in the head of the rail, which then generates electrical tension (Faraday's induction law), and causes eddy currents. These disturb the magnetic field in such a way that the magnetic force is diverted to the opposite of the direction of the movement, thus creating a horizontal force component, which works against the movement of the magnet.

 

The braking energy of the vehicle is converted in eddy current losses which lead to a warming of the rail. (The regular magnetic brake, in wide use in railways, exerts its braking force by friction with the rail, which also creates heat.)

 

The eddy current brake does not have any mechanical contact with the rail, and thus no wear, and creates no noise or odor. The eddy current brake is unusable at low speeds, but can be used at high speeds both for emergency braking and for regular braking.[1]

 

The TSI (Technical Specifications for Interoperability) of the EU for trans-European high speed rail recommends that all newly built high speed lines should make the eddy current brake possible.

Eddy current brakes at the Intamin roller coaster Goliath in Walibi World (Netherlands)

 

The first train in commercial circulation to use such a braking is the ICE 3.

 

Modern roller coasters use this type of braking, but utilize permanent magnets instead of electromagnets, and require no electricity. However, their braking strength cannot be adjusted as easily as with an electromagnet.

 

Basically, the permanent magnets are mounted on the track and a steel or copper reaction plate to the bottom of the roller coasters cars. As this plate passes in between the permanent magnets, eddy currents are created between the magnets which opposes the movement of the reaction plate on the car, causing it to slow the car/train down. The faster this plate moves between the magnets, the more force is created which slows the cars faster. Likewise when it moves through slowly the eddy currents are not as great which induces less force on the reaction plate.

[B-RadG]

That's the reason that Maverick, iSpeed, Sky Rocket, etc have so much crap underneath the trains.

Small LSMs on the track, huge fins on the bottom of the train that run along both sides of the LSMs.

[coasterlover420]

^They are not fins, they are rare-earth magnets. LIM's utilize fins so they don't have to deal with synchronization, whereas LSM's utilize magnets for efficiency. And they really don't have much crap underneath the trains at all; just magnets for launches and brakes, a plate for drive wheels and electrical pins for lap bar release.

 

Basically, the permanent magnets are mounted on the track and a steel or copper reaction plate to the bottom of the roller coasters cars. As this plate passes in between the permanent magnets, eddy currents are created between the magnets which opposes the movement of the reaction plate on the car, causing it to slow the car/train down. The faster this plate moves between the magnets, the more force is created which slows the cars faster. Likewise when it moves through slowly the eddy currents are not as great which induces less force on the reaction plate.

 

Also, eddy currents are generated by a CHANGING magnetic field. So if the train is completely stopped, the magnetic field is not changing, so there are no eddy currents opposing the motion of the train, which is why magnetic brakes can never fully stop a train on an incline; and as you mentioned, it is proportionate to the speed the train is traveling.

___________________

 

The basic concept is somewhat different than Superman. They are still synchronized, but for a different purpose:

The stators are lined up as close together as possible because they are creating a moving magnetic field along the entire track. The point of synchronizing them is to interact with the magnets on the train. The magnetic field in the magnets on the train is basically "dragged along" by the moving magnetic field in the stators. Each stator consists of several coils of wire which are charged at specific times relative to there the train is so as to create a magnetic field to interact with the train. Basically, they are energized one after the other so the induced magnetic field is constantly moving forward, and the train is constantly trying to "catch up." You can see how this can be really versatile because you can program the coils to go off in a certain synchronization so you can very precisely control the speed of the train. That's how the initial lift on Maverick doesn't just launch the train into oblivion and actually slows down a bit before the top. Likewise, the LSM's in the launch tunnel are programmed so precisely that the computer knows exactly where the train is supposed to be for every millisecond during the launch. It's also somewhat evident that it is crucial that they are perfectly synchronized, otherwise the train could "fall out" of the moving magnetic field and the stators will continue to charge down the track and basically waste a crap load of energy (and quite possibly melt the stators).

 

The cool thing about LSM's is that you can tell them to stop at any time during the lift and the stators will basically act like fin brakes and the train will slowly coast backward, which is why they are so safe, whereas if you power off LIM's (like on Wicked Twister), the train will just continue to free swing until friction eventually stops the train several hours later. That is why LIM coasters need a separate set of brakes other than the LIM's.

 

That's just some basics specific to roller coasters. It gets a lot more complicated than this on some occasions

Edited October 22, 2010 by coasterlover420

[mightypotato]

Miracles all up in this thread...

 

[Not For Sale]

^Literally the only reason I came in here was to make this joke.

[Kennyweird]

I'm curious as to how the mechanics of the newer ultra-slim versions work, since I can't see how such powerful electromagnets are crammed into such a small space. Are they contained underneath the tracks?

 

Thanks!

 

The magnetic field intensity of an electromagnet is dependent on the number of times the wire is wrapped around the core (turns) and the current, meaning you can either use a huge number of turns and a relatively low current or a huge current and relatively low number of turns to create a powerful magnetic field. In the case of the ultra-slim LSM's, they use very high current with a low number of turns. This is also why they usually require a flywheel generator-- it would be hard for the grid to provide the high current required to power them.

[aceospades1250]

 

Also, eddy currents are generated by a CHANGING magnetic field. So if the train is completely stopped, the magnetic field is not changing, so there are no eddy currents opposing the motion of the train, which is why magnetic brakes can never fully stop a train on an incline; and as you mentioned, it is proportionate to the speed the train is traveling.

___________________

 

The basic concept is somewhat different than Superman. They are still synchronized, but for a different purpose:

The stators are lined up as close together as possible because they are creating a moving magnetic field along the entire track. The point of synchronizing them is to interact with the magnets on the train. The magnetic field in the magnets on the train is basically "dragged along" by the moving magnetic field in the stators. Each stator consists of several coils of wire which are charged at specific times relative to there the train is so as to create a magnetic field to interact with the train. Basically, they are energized one after the other so the induced magnetic field is constantly moving forward, and the train is constantly trying to "catch up." You can see how this can be really versatile because you can program the coils to go off in a certain synchronization so you can very precisely control the speed of the train. That's how the initial lift on Maverick doesn't just launch the train into oblivion and actually slows down a bit before the top. Likewise, the LSM's in the launch tunnel are programmed so precisely that the computer knows exactly where the train is supposed to be for every millisecond during the launch. It's also somewhat evident that it is crucial that they are perfectly synchronized, otherwise the train could "fall out" of the moving magnetic field and the stators will continue to charge down the track and basically waste a crap load of energy (and quite possibly melt the stators).

 

The cool thing about LSM's is that you can tell them to stop at any time during the lift and the stators will basically act like fin brakes and the train will slowly coast backward, which is why they are so safe, whereas if you power off LIM's (like on Wicked Twister), the train will just continue to free swing until friction eventually stops the train several hours later. That is why LIM coasters need a separate set of brakes other than the LIM's.

 

That's just some basics specific to roller coasters. It gets a lot more complicated than this on some occasions

 

Thanks man! This makes perfect sense and is exactly what I was asking. It's amazing how far this technology has progressed since it was introduced. I remember reading about the horror stories of getting Superman synchronized properly, and now it seems like a new LSM coaster is being opened every few months with no issues. I have a feeling this kind of technology will eventually replace all the moving parts that are typical in rides that use chain/cable lifts or hydraulic launches. It just seems like a safer more reliable system that combines the best aspects of a LIM launch and a cable launch. Kinda like how you very rarely see a new ride that relies solely on pinch brakes to stop the train; almost all modern rides have some kind of eddy-current braking included.

 

The magnetic field intensity of an electromagnet is dependent on the number of times the wire is wrapped around the core (turns) and the current, meaning you can either use a huge number of turns and a relatively low current or a huge current and relatively low number of turns to create a powerful magnetic field. In the case of the ultra-slim LSM's, they use very high current with a low number of turns. This is also why they usually require a flywheel generator-- it would be hard for the grid to provide the high current required to power them.

 

Ok, I didn't know about this either. Makes perfect sense though, thanks for the info.

[coasterlover420]

^Well, there are practical reasons cable lifts/chain lifts and hydraulic launches are used instead of LSM's. They may require more maintenance, but they are much more cost effective (based on the electric bill, basically). Hydraulic launches, on the other hand, are used for sheer force. It would take LSM's a lot more than 4 seconds to get a train up to 150mph. The coaster would need a much longer launch track and a lot more electricity.

[Tmcdllr]

Wow, I guess I posted for nothing!

 

Rather than just explaining how I thought they worked i went to companies sites that actually make them that know precisely how this stuff works, whatever.

[aceospades1250]

Wow, I guess I posted for nothing!

 

Rather than just explaining how I thought they worked i went to companies sites that actually make them that know precisely how this stuff works, whatever.

 

Nice copy-paste job bro. Didn't answer my question anyways.

[Tmcdllr]

^Yes it was and it was very informative....bro.

[coasterlover420]

^Companies can tell you what LIM's technically are and what they can possibly do, but usually they are not specific to roller coasters, which is why I included the explanation. I learned more about LIM's from US patents than I did from sites for companies that sell them. This one for example.

[Tmcdllr]

^Your explanation is very good as it is specific to rollercoasters. What I posted was a general explanation for those, in general and unfortunately not rollercoaster-specefic. In fact, I dont think I've ever seen an explanation of these on here before that was as well put as yours. Trying to get this from, say Intamin, is impossible, they dont want everyone to know exactly how their "technology" works but obviously people know about it.

 

Too bad we cant go back in time. Instead of the long drawn out generic info I posted, I would have instead just said, "yeah, I've always wondered how that stuff works too" then you could have made your awesome post and that would be it.

[Erik_73]

To answer the original question; those thin sexy LSM stators are called InTraSysSLIM stators. Officially they should call it ILSM; what stand for Ironless Linear Synchronous Motor. The big difference between the "old" LSM systems like on SFMM Superman, the stators are very big while the coils have a weak iron core and the new SLIM stators haven't.

[TPDave]

Guys, can we stop bitching about who answered the question best please.

 

Thanks for the InTraSys link Erik. Would I be right in saying that InTraSys do pretty much everything in modern magnetic launches?

 

Dave

[Tmcdllr]

^ I wasn't 'bitching' in my last post and I was admitting that the other post of info was better.

 

Enough of that.

 

On that site is this cool pic of what looks like an Intamin inverted launch coaster, where you can see the LIMs and brakes.

 

 

So this is the company that makes this stuff for Intamin? I've been wondering who it was.

[coasterlover420]

^Yeah, if you look close enough to some of these coasters, it's pretty cool what you can find labeled on the parts. Most of the stators are InTraSys, pretty much all of the control panels are Allen-Bradley...etc.

 

I find their site to be pretty fun with the help of http://translate.google.com/

[Tmcdllr]

Oh yeah, I know Allen Bradley. At work we use their motor contactors.

[Erik_73]

Would I be right in saying that InTraSys do pretty much everything in modern magnetic launches?

 

That is pretty much correct; the majority of all the newer launch coasters are equipped with InTraSys SLIM launches. Although I'm not sure if Intamin uses them too. Those stators on iSpeed (listed as LSM on RCDB) and Maverick are looking slightly different to the InTraSys stators. While I can not see any position sensors in between those stators I doubt if these are LSM or just ordinary LIM systems.

[coasterlover420]

^Well, it is doubtful considering there aren't position sensors over the entire launch track (in the case of iSpeed and Maverick), but they are still LSM motors. Regular LIM's don't need to be as perfectly synchronized as LSM's do because they don't involve permanent magnets; but when magnets are used as the rotor instead of copper fins, the stators must be synchronized very precisely. I suppose in the case of these two coasters, it is just done with a computer by sensing where the train is before the launch begins and then timing it perfectly after that; because as far as I have observed, there are a great deal of sensors before each launch on Maverick.

 

Don't quote me on this, but this is as close as I can get to an accurate description with close observations. I hope this helps.

[Erik_73]

^ I only know a bit how the IntTraSys LSM system works; but they measure the position of the train in the launch with a bizarre accurate and fast (optic fibre) measuring system. The system needs this precise train position to calculate the phase angle for the drive(s). I doubt if the drive could launch with LSM without position feedback; but maybe other manufacturers have a different way to obtain the train position.

[coasterlover420]

I have been doing some digging, and found this picture.

As you can see, there are proxys so the computer knows the lift block is occupied, but there are also thin white sensors between several of the LSM's lining the lift (and also a single one a few feet before the first stator). They may not occupy every gap between the stators, but they are enough to acknowledge the position of the train at all times. I'm not sure how they work, but I'm guessing they are somewhat like proxys, which sense eddy currents in metal that is really close. My guess is they sense the magnetic flux when the magnets pass by them?

 

I actually noticed this today on Half Pipe and thought I'd get looking for some good pictures

[Erik_73]

^ Yep that are obviously positioning sensors. So Intamin is one of the few companies that uses another brand of LSM drive than most of their compettetors but due to the thickness of the stator I assume that it are also ironless stators as well.

[coasterlover420]

Here is a picture under the maverick trains showing the size and polarity of the magnets that interact with the stators.