Product Description:

The B-104-B-21 is a brushless servo motor manufactured by Kollmorgen as a member of the Goldline B and BH Motors series. Designed for closed-loop positioning and velocity control, the unit supplies direct output torque to indexing tables, pick-and-place axes, and electronic gearing assemblies common in industrial automation. Its compact form factor lets machine builders place the motor close to the load, reducing mechanical compliance and improving dynamic accuracy. Because it uses brushless operation, the motor avoids the wear associated with mechanical commutation and supports repeatable motion over long duty cycles.

Electrical performance is set by the motor’s back electromotive force of 22.5 VRMS/kRPM, which is the voltage returned to the drive per thousand revolutions and helps match amplifier ratings. At 25 °C, it delivers a continuous torque of 1.67 N·m while drawing a continuous phase current of 4.20 A RMS, and that torque drops to 1.57 N·m when the winding temperature reaches 40 °C. The phase-to-phase resistance at 25 °C is 2.72 Ω, which affects copper losses during steady operation. The three-phase stator winding has an inductance of 14.4 mH, which moderates current ripple and affects current-loop bandwidth. At its rated speed of 7500 RPM, the motor operates within these thermal limits, and position feedback is provided by a frameless resolver embedded in the housing. That feedback arrangement supports commutation and helps the drive maintain smooth speed regulation as the load changes.

Short-duration demands are handled by a peak current of 12.6 A RMS, allowing the electromagnetic system to generate a peak torque of 4.45 N·m for rapid acceleration. The rotor’s reflected inertia is only 0.0000461 kg·m², so drive axes can change speed quickly with limited control effort. With a rated mechanical power of 1.1 kW and a torque sensitivity of 0.37 N·m/A RMS, the motor converts current into motion efficiently. The design accepts up to 250 V RMS line voltage through a bayonet connector supplied without mating plugs, and it uses metric mounting with IP65 sealing and a rear shaft extension for integration into sealed equipment frames.