Product Description:

The U12M4 is a permanent-magnet DC motor produced by Kollmorgen within the ServoDisc Pancake DC Motors series. The flat armature architecture gives a short axial length while preserving output torque for conveyor indexing, semiconductor positioning, and other automated axes that need bidirectional speed control from a low-inertia rotor. In a machine frame, the motor acts as the prime mover and connects to a servo amplifier that regulates armature current to command torque.

The electrical design centers on a nominal supply of 43.4 V, and at this level the armature draws 8.8 A when delivering the rated load. The coil set has an armature resistance of 0.610 Ω and a separate terminal resistance of 0.750 Ω, which affect copper losses and drive sizing. Each ampere flowing through the windings produces torque in proportion to the torque constant of 11.04 N-cm/A. Conversely, the spinning rotor produces back electromotive force according to a voltage constant of 11.55 V/KRPM. These linear constants allow the controller to predict voltage demand, manage regenerative braking, and maintain closed-loop velocity without overshoot.

The disc armature provides a continuous stall torque of 86 N-cm, while short transients can reach a peak torque of 929 N-cm before presenting a demagnetization risk. Rated operation occurs at 3000 RPM, although the commutation and bearing system permit excursions up to 6000 RPM when the duty cycle is reduced. At the rated speed and magnetic loading, the shaft provides a continuous power output of 284 W. The motor has an outside diameter of 139.7 mm and a body length of 53.3 mm, producing a compact cylindrical profile with a weight of 3.6 kg. Torque capability declines slightly as temperature increases, moving from 91 N-cm at 25 °C to 81 N-cm at 40 °C. This temperature-related reduction should be considered when arranging airflow and managing heat in an enclosed cabinet.