Advantages & Typical Characteristics of Linear Induction Motors
What Can Linear Induction Motors (LIMs) Do?
LIMs are simple to control and easy to use, and can be developed to produce a fast response, high acceleration and high braking forces. LIM operating speed is not dependent on contact friction, as there is no direct physical contact between LIM stator and rotor. There are no gears or chains to cause backlash, no lubrication and no maintenance. Mechanical transmissions are often eliminated leading to a great increase in reliability, and fewer moving parts allow much simpler systems to de used. The simplicity and reduced maintenence requirements of LIM drives mean that long term operating costs are often greatly reduced.
Horizontal travel is only limited by the length of the reaction plate or motor and long tracks such as conveyors or amusement rides can use multi-motor systems. Either the powered stator or the unpowered reaction plate can move whilst the other is fixed, giving the optimal system configuration based on user requirements. If a conductive disc is substituted for the reaction plate rotary motion is produced.
Motion is not dependent on friction between wheels and rails so LIMs can be used in extremely adverse conditions. A non-magnetic stainless steel barrier can be used between stator and reaction plate or stators can be entirely sealed within a protective stainless steel can. When unpowered, LIMs are non magnetic and do not attract stray particles of ferrous material, which can be a common problem with machines using permanent magnets.
The LIM makes an ideal variable speed drive. Not only does it behave like a magnetic clutch and give a soft-start action, but speed can be controlled to a high degree of accuracy with suitable control systems.
Where Are Linear Induction Motors Used?
Wherever straight line motion or reciprocating forces are needed, or where non standard drive solutions are required. LIMs are ideal for applications where space is at premium. LIMs are also extremely rugged and are well suited to operation in hazardous environments.
Some typical applications of LIMs are listed below. For more information, please see our application case studies
| Sliding Doors | Sewage Distributors | Automated Warehousing |
| Aluminium Can Propulsion | Crane Drives | Stage/Curtain Movement |
| Mixer/Stirrer Drives | Scrap Sorting/Movement | Revolving Doors |
| Baggage Handling | Flat Circular Motors | Linear Accelerators |
| Flexible Manufacturing Systems | Personal Rapid Transport Systems | Ship Test Tank Drives |
| Bogie Drives | Turntable Drives | Target Movement |
| Steel Tube Movement | Wire Winding | Slewing Drives |
| Sheet Metal Movement | Pallet Drives | Research Machines |
| Automated Postal Systems | Multi-Motor - In-Track Systems | Theme Park Rides |
| Extrusion Pullers | Robotic Systems | People Movers |
| Low Profile Drives | Conveying Systems | Airport Carousels |
Typical Characteristics
Typical Forcepack motor sizes in mm
(Thrust (Newtons) at 400 volts 50Hz and 20% duty cycle)
| Thrust | Length | Width | Height |
|---|---|---|---|
| 80 | 175 | 137 | 80 |
| 130 | 280 | 137 | 80 |
| 190 | 280 | 155 | 83 |
| 240 | 390 | 155 | 83 |
| 330 | 390 | 190 | 85 |
| 410 | 500 | 190 | 85 |
| 600 | 500 | 250 | 85 |
| 710 | 608 | 250 | 85 |
| 820 | 710 | 250 | 85 |
| 1000 | 800 | 250 | 85 |