Product Description:

The N9M4LRT is a flat-armature DC motor produced by Kollmorgen for the ServoDisc Pancake DC Motors series. Its disk-shaped construction allows the shaft to couple directly to loads without gear reduction, saving space in pick-and-place heads, gimbals, and small conveyors. In industrial automation, the unit converts controlled armature current into proportional torque, providing a compact alternative to traditional cylindrical motors when precise speed regulation and rapid reversals are required. The low-profile housing also supports installation in machinery where axial clearance is limited.

Drive electronics connect to a rated terminal voltage of 14.0 V, and the armature has a resistance of 0.370 Ω, so steady-state current remains near the intended value under nominal load. The motor produces torque according to its constant of 3.39 N-cm/A. At the rated continuous current of 12.90 A, the motor provides a steady output of 36 N-cm at 25 °C. A laminated armature disk and rare-earth magnets support a power output of 114 W while keeping back electromotive force at 3.60 V/KRPM, which the drive must overcome during acceleration. A tachometer winding supplies 3.50 V/KRPM for closed-loop speed feedback. Thermal resistance at stall is 2.10 °C/W, allowing predictable heating calculations, while peak current reaches 147 A for brief acceleration or load-change events.

The mechanical section responds quickly because an 8.80 ms time constant and a rotor inertia of 0.59 kg-cm² support high-bandwidth position loops. Continuous stall capability is 40 N-cm, preserving holding force without overheating, while dynamic events can use a peak torque of 468 N-cm. Base operation is centered on 3000 rpm, which matches the motor’s electrical operating point. The flat rotor can safely reach 6000 rpm when an application requires higher process speed. Its low rotor inertia reduces the energy needed for acceleration and deceleration, helping the motor respond promptly to changing motion commands. The integrated tachometer signal allows the connected drive to correct speed deviations during load changes without requiring a separate external speed sensor.