Trilogy Ironless Linear Motors are prime movers with substantial speed and positioning performance advantages over rotary motors used with balusters, timing belts., rack/pinion drives and friction drives. They are linear three phase brashness DC motors, also known as AC servo motors, that are powered by standard brashness amplifiers operating in torque or current mode with, typically, a linear encoder for position feedback to a motion controller to control position, velocity and acceleration.

Trilogy Ironless Linear Motors can operate with a wide range of commercial linear encoders, drive amplifiers, and motion controllers. Trilogy has developed a database of application notes to aid the customer in product selection and usage. Contact a Trilogy engineer for application assistance and auxiliary information.

High Accuracy and Repeatability
Positioning to +/-1 encoder count down to submicron resolutions.

Mechanical Simplicity
Only two parts - a moving coil and a stationary magnet track. Without couplings the produced force is directly applied to the load.

High Accelerations and Velocities
Practical accelerations of 2-3g's are normal with up to 15 g's in special instances. Velocities are limited by the encoder data rate and the amplifier bus voltage. Normal peak velocities reach 2m/s and up to 8 m/s in same applications.

Heat Removal Capability
A unique planar surface formed between the windings and attachment bar provide maximum heat transfer capability. The result is high sustainable currents and forces. A thermostat and air or liquid cooling are included at no extra cost in all coil models where design permits.

No Wear or Maintenance
Non=Contacting parts are ideal where long life without degradation of performance is required.

Design Flexibility
Three styles of magnet track allow for maximum flexibility and value. The standard magnet track can be customized at no extra cost. The modular and folded modular tracks allow for immediate delivery and even greater value.

Ease of Installation
All motors are designed with substantial alignment tolerances and misalignment produces no degradation of performance.

Positioning System Size Reduction
No additional length is required for rotary motors or motor couplings as with ball screw or timing belt drives. The result is a smaller and more compact design.

Superior Performance
With proper sizing of motor to load, there is no higher performance available than LM motors. Accuracy, repeatability, acceleration, velocity, stiffness, cycle life are all superior to other technologies.

Clean Room Compatibility
Vacuum compatibility and no contact design permits use in Class 1 Clean Rooms.

The LM Series motors are three=phase brushless DC servo motors. They operate exactly as rotary motors, using basic electrical physics equations that describe the relationship between a current flowing in a conductor in a magnetic flux field with a resultant produced force. By maximizing the number of turns with efficient winding packing in the Coil assembly, and by using the most powerful rare earth magnets in the Magnet Track, very large forces are created in a small package. The windings are accurately or commutated to sustain motion.

Trilogy motors are available with two types of motor commution; Sinusoidal and Hall Effect Device (also known as HED or Trapezoidal). The highest motor efficiency is obtained with Sine commution with HED commution height about 10-15% less efficient. In Sine commution, the linear encoder used for position feedback is also used to commutate the motor. Phase finding (supported by either the drive or controller) is required on power-up and then the motor phased are incrementally advanced with each encoder pulse. This produces extremely smooth motion. In HED commutation, a circuit board embedded in the coil assembly contains small Hall Effect Device IC's. The HED sensors detect the polarity change in the magnet track and switch the motor phases every 60⁰.

From experimental testing, Trilogy's sinusoidal commutated motors are approximately 10% more efficient than our HED commutated motors. The reason for this is the motor's fundamental design. With Trilogy's advanced manufacturing techniques, the windings are accurately configured in the motor coil to yield a sinusoidally shaped characteristic Back EMF waveform. When the driving voltage on each phase matches the characteristic Back EMF waveform there is no force ripple. The Back EMF waveform results from the geometry of the magnets and windings. Compared with similar style linear motors(Sine or HED commutated), using Sine commutation with Trilogy motors results in high efficiency, quiet operation, and the smoothest cog free delivery of power to the payload.

All motors - rotary or linear - are limited in performance by their ability to eliminate or transfer heat produced in their windings. As current flows in the windings, useful force is produced but also detrimental heat. The power lost through heat is equal to E=I²R. The limitation in performance is that without adequate thermal transfer and proper motor sizing the windings will increase in temperature until the motor fails. Linear motors, unlike rotary motors, do not have large surface area, finned cylindrical metal housings to assist in heat rejection.

Trilogy's Ironless Linear motors utilize a combination of very high motor efficiency, heavy duty, high temperature magnet wire, and good thermal conduction from the windings, to the aluminum attachment bar to reject heat. Trilogy forms the windings during fabrication into a planar surface at the interface with the attachment bar. This motor design is covered by U.S. patent no. RE34674. At the interface between the winding planar surface and the aluminum flat surface, heat transfer is maximized. Once heat is transferred internally from the windings to the motor's coil attachment bar, it is rejected through a carriage assembly or carried away by air or liquid cooling. Use of silicone grease is always recommended on the coil mounting surface.

As with all motor applications, it is important to size linear motors according to the continuous or RMS current. A factor in sizing is to consider the heat sinking capability of the carriage plate to which the coil is attached. The type and style of carriage plate can and does effect the amount of heat removed. Trilogy's Motor Sizing TIPS computer program predicts temperature rise in the linear motor coil using customer specified loads and motion profiles. The program's data base of heat dissipation constants was determined by experimental testing using conservatively sized carriages. It is highly recommended to always verify motor sizing calculations by using TIPS.