Linear electric motor
(ironcore, asynchronous) H2W Technologies

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