Product Description:

The U12M4HA is a pancake-style DC servomotor manufactured by Kollmorgen within the ServoDisc Pancake DC Motors series. As a low-profile direct-drive component, it provides shaft power to indexing tables, card feeders, and other motion axes without gear reduction. Its frameless construction minimizes inertia, allowing industrial control systems to position loads quickly while maintaining consistent torque throughout a full rotation. The compact profile also allows the motor to operate in applications where the available axial installation space is limited.

At its rated operating point, the motor accepts a terminal voltage of 65.6 V and runs at 3000 rpm, delivering up to 329 W of mechanical output. A continuous stall torque of 106 N-cm is available when the shaft is locked while the motor remains energized, establishing the thermal limit for static holding applications. Electrical losses are governed by a winding resistance of 1.170 Ω, allowing the drive electronics to estimate copper heating from the applied current. During motion, the armature generates a back electromotive force of 18.50 V/krpm, which supports regenerative braking calculations and helps determine the required voltage headroom at high speeds. These operating values describe separate electrical, mechanical, and thermal characteristics without duplicating the motor’s dynamic ratings.

During brief dynamic events, the motor can deliver a peak torque of 1130 N-cm, provided that the drive can supply the associated 65 A surge current while observing the permitted duty cycle. The maximum recommended speed is 6000 rpm, so the connected encoder and commutation hardware must remain accurate across the operating range. A torque constant of 17.68 N-cm/A relates commanded current to output torque and supports accurate current-loop tuning. The motor has an outside diameter of 139.7 mm and a stack length of 70.6 mm, allowing it to fit compact direct-drive mechanisms. It supports an axial load of 55 lb and a radial load of 60 lb. Continuous operation uses a current of 6.5 A and produces a rated torque of 104 N-cm for thermal sizing.