FiberPrinted™ Slotless Motors

Precision of Slotless motors

FiberPrinted™ motors exhibits a perfectly linear behaviour in all nominal conditions due to the absence of cogging torque, low back-EMF THD & that they essentially never saturate. This allows for ultra-precise angular control with simple control-electronics & control-algorithms.

A FiberPrinted™ motor has zero cogging torque due to the symmetrical magnetic interaction between the stator & the rotor. A symmetrical magnetic interaction is achieved since the laminations around a FiberPrinted™ stator is perfectly cylindrical.

Due to the geometrical simplicity of a FiberPrinted™ motor in combination of a Halbach array rotor, the stator & rotor can be optimised to generate an almost perfect sinusoidal back-EMF even at high torque-levels & temperature fluctuations.

Performance of Slotted motors

The technical advantages of FiberPrinting™ result in slotless motors that are far superior to any other motor technology for high-precision applications. A FiberPrinted™ motor has the same motor-constant vs. mass ratio as a slotted motor. This means that a FiberPrinted™ motor has the same continuous power & torque density as a slotted motor.

FiberPrinted™ motors also have the advantage of virtually no saturation of the stator, enabling a peak torque well beyond that of an equivalent slotted motor.

The performance advantages of FiberPrinted™ motors allow you to transition from slotted motors to improve precision without incurring any performance or weight penalty. Additionally, they can replace legacy precision slotless motors to enhance both performance & weight.

Large ID/OD ratio

Alva’s slotless motor technology results in a thin stator & rotor compared to both slotted motors & other slotless motors, allowing a large inner diameter of the rotor. Other components, for example gears, can more easily be placed inside the frameless motor, to increase overall system compactness.

Low speed-dependant losses

One of limiting factors of iron-cored motors is the strong magnetic interaction between the magnetic field from the rotor & the iron-teeth of the stator. The strong magnetic interaction generates losses in the iron-teeth which grows exponentially with the rotational speed.

The magnetic interaction between the rotor & the lamination ring in a FiberPrinted™ stator is highly reduced since the distance between them is increased. The iron-losses of a FiberPrinted™ motor are therefore negligible compared to other losses. The reduced iron-losses allows for both higher efficiency at high rotational speed & for large diameter motors without any performance penalty.