Why a Disc Magnet Motor

Disc Magnet Motor Diagram

Our disc magnet motors provide exceptional dynamic performance unparalleled by any other stepper in the market. The unique thin disc magnet enables finer step resolutions in the same diameter, significantly higher acceleration and greater top end speed than conventional steppers. Disc magnet motors excel in applications that require the precision of a stepper and the speed/acceleration of a brushless DC motor. Closing the loop provides a competitive advantage against a servo solution.

The exceptional possibilities offered by our line of disc magnet stepper motors are unequalled by any other kind of stepper motor. Their advanced technology, developed by Portescap, allows for truly exceptional dynamic perfor­mance. The rotor of these motors consists of a rare earth magnet having the shape of a thin disc which is axially magnetized.

A particular magnetization method allows for a high number of magnetic poles, optimized for the motor size, giving much smaller step angles than convention­al two-phase permanent magnet stepper motors. Their very low moment of inertia results in outstanding accelera­tion and dynamic behavior. These fea­tures, together with high peak speeds, mean that any incremental movement is carried out in the shortest possible time. Their low inertia also means high start/stop fre­quencies allowing them to save time during the first step and solve certain motion prob­lems without applying a ramp.

Our disc magnet motor line of stepper motors can easily be tailored to your application requirements. Our design team can help integrate a motor into your assembly by providing additional components, or by designing a fully customized motion solution that optimizes the space and performance of your machine.


Features Characteristics Advantages
Thin multipolar rare earth disc magnet Low rotor inertia High acceleration, high start and stop frequencies
High power rate (T^2/J)
Short iron circuit made of SiFe laminations
Coils placed near the airgap
Low iron losses
More torque at high step rates
High speeds
High power to volume ratio
Simple magnetic circuit No coupling between phases
Sinusoidal torque function
Low detent torque
Superior angular resolution in microstep mode
Optimally dimensioned iron circuit Torque constant linear up to 2 times nominal current High peak torques
Capability to boost current


Disc Magnet
Thin disc magnet provides high acceleration and speed capability