Product Description:

The PMB31B-10101-02 is a brushless servo motor manufactured by Pacific Scientific and included in the PMB Brushless Servomotors series. It is intended for closed-loop positioning and velocity control in automated pick-and-place stations, indexing tables, and small gantry axes where repeatable motion is required. Electrical and mechanical interfaces follow common U.S. industrial layouts, which helps the motor fit compact automation assemblies. This configuration is suitable for motion systems that need accurate starts, stops, and speed changes without the maintenance concerns of brush wear.

The motor uses a compact NEMA Size 34 frame, so it fits directly on gearboxes or brackets designed for this class. Power conductors exit as flying leads with AMP connectors, allowing quick field termination without additional junction hardware. Under worst-case stall at 240 VAC, the windings draw a nominal current of 2.7 ARMS, which helps size the drive's continuous current rating. Rotor position feedback comes from a three-phase Hall sensor, giving 120-degree commutation signals that many standard servo amplifiers can interpret without sine-cosine encoders.

A built-in PTC Thermistor changes resistance sharply near the safe winding temperature so the drive can reduce current before insulation limits are reached. The thermal sensor also provides a simple protective input for the connected drive or control circuit. The output uses a round shaft, simplifying coupler selection when backlash or keyway alignment is not critical. Because the shaft is plain rather than keyed, torque transfer typically relies on a clamp-style hub or similar friction coupling. The motor uses a stack length multiple of 1, representing the shortest lamination segment in this frame. This shorter magnetic stack helps limit total inertia, which benefits high-speed start-stop cycles in semiconductor handling and lightweight conveyor systems.