Product Description:

The PMB31B-101114-00 brushless servomotor is manufactured by Pacific Scientific within the PMB Brushless Servomotors series. Designed for closed-loop positioning and speed regulation, this motor converts electrical commands from a drive into controlled rotary motion for pick-and-place units, indexing tables, and other automation axes. Its permanent-magnet design and integrated encoder allow controllers to maintain repeatable motion profiles, while the brushless configuration reduces mechanical wear during frequent operating cycles.

With a NEMA Size 34 frame, the motor mounts directly to standard 3.4-inch square flanges for integration with compatible motion hardware. A continuous stall capability of 2.11 Nm indicates the torque it can maintain without rotor movement, while the nominal stall current of 2.7 A RMS establishes the steady-state current required from the drive at 240 VAC. The torque constant of 0.79 Nm/A RMS links commanded current to produced torque, allowing drive tuning values to correspond to mechanical output. An inductance of 19.6 mH limits rapid current changes, reducing audible noise and smoothing low-speed performance. Position feedback is supplied by a 2048-ppr encoder with commutation tracks, supporting accurate rotor position monitoring and electronic commutation. Flying leads terminated with AMP connectors provide a direct connection to panel wiring.

During acceleration, the motor can deliver a peak torque of 6.26 Nm, providing brief reserves for overcoming static friction or inertial loads. The voltage constant of 0.49 V RMS/rad/s indicates the back electromotive force that the controller must counter during high-speed operation, and the phase resistance of 7.6 ohms affects copper losses and thermal rise. A thermal resistance of 1.08 °C/W indicates how effectively heat leaves the stator and helps determine the required enclosure airflow. The rotor inertia is 0.137 × 10⁻³ kg·m², and the stack length multiple is 1. The round shaft transmits torque without a keyway, while the complete motor assembly weighs 2.5 kg.