Ironless Linear Motors

An often unasked but important question is, what is unique about an ironless linear motor?

Iron Core family of products

The answer is that ironless linear motors use powerful, permanent magnets to create a strong magnetic field that surrounds the active coil conductors. When current is applied, a force is produced that is directly proportional to the current. There is no iron in or around the coil, and even though this makes the motor slightly less-efficient, it greatly reduces the coil inductance, thus allowing the motor to quickly respond to changes in current with high fidelity.

Additionally, no iron in the coil means that the coil is not attracted to the magnets. This attraction causes a varying preload and varying force – or cogging – that the motor must overcome as it travels. This can add heat to the system, further reducing efficiency. That is why ironless linear motors power the most-accurate motion applications.

Iron Core family of products


The P-Series is our workhorse, sporting our highest force density, superb electrical phase balance, flexible in-field electrical connection choices and the largest number of configurable options, resulting in motor implementations with the highest-degree of veracity.


The Airex C-Series motors provide a low overall height and are ideal for compact or micro stages. Airex linear motors are thinner than most of our competitors’ motors, but still offer you top performance and superior settling.

Why is the motor used with closed loop control?

When considering motion element modeling, the linear motor acts like a very special spring where current direction and flux strength dictates the spring constant. When the motor is part of a closed loop control system (i.e. the motor is an actuator, an encoder is the feedback device, and together with an electronic controller they form a closed loop system), the motor or spring as described can move at a very constant velocity or stop at an exact position.

Ironless linear motor applications

With Airex’s patented coil winding technology our linear motors are the ideal solution for actuators, precision stages, photonics platforms, semiconductor equipment, pick-and-place systems and inspection systems that require exceptionally responsive control at high bandwidths while simultaneously maintaining a low heat rise. Your solution may require an IRON core linear motor, utilizing high-temperature rare-earth magnets, from our P-Series or C-Series linear motors (all customizable).

Unmatched performance

Airex motors deliver the highest motor constant (Km) in any similar volume of motor because of our patented copper coil manufacturing and winding methods. This expertise grants precise control at low velocity and superior point-to-point settling times. Our manufacturing method ensures precision placement of the conductors with minimal end turns, providing the highest slot fill in the industry as well as the best thermal path available on the market. High-energy, rare earth magnets complete the magnetic circuit.

Our motor is ideal in ultra-precision direct drive systems. The high intrinsic coil stiffness we employ eliminates backlash and windup inherent in other linear driven systems. Airex’s linear motors also eliminate the wear problems typically associated with ball-screws, belt drives and rack-and-pinion linear motion systems.

solar and photonics

Tailored to your needs

A portion of our motors are sold as configured on our website and in the catalog. However, many of our customers customize our linear motors to suit their specific application. The customizations range from simple metric holes to special models specific to your requirements. Categories of customization include:

  • Added holes that ease assembly, assist motor mounting and integrate special functions
  • Special mounting brackets or custom integration of coil assemblies into customer stages
  • Special cables
  • Special thermal sensors
  • Vacuum compatibility via special fasteners, bleed channels, special platings or materials
  • Cleanroom features including special cleaning and packaging
  • Custom and private labeling
  • Multi-unit coil modules
  • Special magnet tracks
  • Bracketless coil assemblies (ideal for integration into your stage)

Ready to connect on how Airex can address your specific needs?