U9M4HA

The Kollmorgen U9M4HA brushless servo motor from the ServoDisc Pancake DC Motors series combines a compact, disc-shaped form factor with high torque density and precision motion control capabilities. Designed for industrial automation and direct-drive applications, the U9M4HA delivers a peak torque of 395 N-cm while maintaining smooth, low-inertia operation. Its ironless disc armature minimizes inertia, enabling rapid response times and reduced vibration, making it ideal for applications where space efficiency and dynamic performance are critical. The motor seamlessly integrates with Kollmorgen's KXA Plus and EM19 series servo drives, supporting a range of feedback options and connectivity protocols for versatile system architectures. With a maximum recommended speed of 6000 RPM and a rated speed of 3000 RPM, the U9M4HA balances high-speed capability with reliable continuous operation.

Technical specifications of the U9M4HA underscore its robust electrical and mechanical design. It operates at a rated terminal voltage of 34.7 Volts and sustains a rated power output of 138 Watts, while drawing a rated continuous current of 6.8 Amps under full load. Continuous stall conditions see a continuous stall current of 5.3 Amps producing a continuous stall torque of 35 N-cm. Thermal performance is rated at 44 N-cm continuous torque at 25°C and 40 N-cm continuous torque at 40°C, ensuring reliable operation across ambient temperature ranges. The motor’s peak current capability of 56 Amps supports high torque demands, and its moment of inertia of 0.2 kg·m² and static friction torque of 2.8 N-cm deliver responsive control in precision tasks.

Operational features emphasize performance under varied conditions and ease of control integration. The pancake form factor—with a length of 2.39 inches, a diameter of 4.37 inches, and a mass of 2.4 kilograms—minimizes footprint without compromising structural rigidity. The ironless armature design reduces cogging torque, enabling smooth starts and stops, while optional fail-safe brakes meet safety requirements in critical applications. Available in configurations with either internal or external tachometers and supporting optical encoder feedback, the U9M4HA provides high resolution positional accuracy. Maintenance and cooling needs are modest, as the motor’s efficient thermal characteristics limit heat buildup during continuous operation.

System integration of the U9M4HA is streamlined by compatibility with Kollmorgen's KXA Plus and EM19 servo drives and a broad selection of feedback devices. The motor’s direct-drive architecture eliminates the need for gearboxes, reducing system complexity and backlash. It is ideally suited for high-precision tasks in semiconductor handling, medical device assembly, and pick-and-place robotics where accurate, repeatable motion is critical. Qualified personnel should handle installation and commissioning, given the high voltage and current ratings of the system.