BAUMULLER GDM120N-528/0750: Low-Inertia DC Disc Motor
BAUMULLER GDM120N-528/0750 is a permanent-magnet DC disc motor from the GDM series, engineered for precision drive applications requiring extremely low rotor inertia and a compact axial profile. The motor belongs to Baumüller’s coreless disc motor lineup, a design family recognized for combining high dynamic response with a space-saving flat form factor.
Coreless Rotor and Dynamic Performance
The defining feature of the GDM series is its ironless disc armature paired with a drum-shaped commutator. This construction eliminates cogging torque entirely, allowing smooth rotation even at very low speeds and precise concentricity during positioning tasks. The absence of an iron core also yields an extremely low moment of inertia, enabling rapid acceleration and deceleration cycles that suit high-duty servo applications. The NdFeB permanent magnet assembly provides high torque density within the compact frame, while the robust wire wrap and commutator design contribute to overload capacity and reduced brush wear over the service life.
Mechanical Profile and Integration
GDM disc motors are characterized by their shallow axial dimensions. In its shortest construction, the series requires only 39.5 mm of axial installation space, positioning the GDM 12 N frame as one of the slimmest disc motors available in relation to its power output. The GDM120N frame size uses a 120 mm outer diameter with a flange mount compatible with standard IEC face dimensions. Optional factory configurations include integrated tachometers, incremental encoders, holding brakes, and gearboxes, allowing the motor to be adapted to closed-loop servo or feedback-driven speed control architectures.
Application Context
The GDM120N-528/0750 is typically deployed in space-constrained equipment where fast response and smooth low-speed rotation are critical. Common installations include precision winding and tension control systems, printing and converting machinery, and compact positioning axes in automated handling equipment. For maintenance and spare-part planning, the motor is a brushed DC design that operates without internal firmware, making it compatible with standard four-quadrant DC servo drives and PWM amplifiers configured for permanent-magnet motors. Verification of armature voltage and current limits against the drive parameters is recommended before commissioning.
