Product Description:

The PMB31B-20101-01 is a brushless servomotor produced by Pacific Scientific and supplied within the PMB Brushless Servomotors series. As a permanent-magnet motor, it converts drive current from a matching servo amplifier into controlled rotary motion for positioning or velocity tasks in automated machinery. Its electromagnetic design supports rapid torque production while reducing the maintenance associated with brushed devices. This makes the motor suitable for axes that require responsive starts, stops, and repeated speed changes during normal operation.

The frame is built to NEMA Size 34, so its mounting face aligns with standard 3.4-inch square bolt patterns commonly used on medium-torque axes. Internally, the motor uses a brushless rotor and stator arrangement, which eliminates commutator wear and supports repeated high-speed cycling. Power and feedback are routed through Flying leads with AMP connectors, which allow cable routing to suit the machine layout. When the shaft is locked, the winding can accept a nominal stall current of 2.7 ARMS from a 240 Vac drive without exceeding rated thermal limits, allowing full continuous torque at zero speed. Rotor position is detected by a three-channel Hall Sensor that supplies 120-electrical-degree signals for amplifier commutation. Output torque is transmitted through a Square Key shaft, which helps prevent slip when the motor is coupled to pulleys, couplings, or gearboxes under cyclic load.

The motor can be equipped with a Shaft Seal to protect internal bearings when it is installed in oily or dusty environments. The magnetic stack uses a length multiple of 1, which keeps the motor in the base torque configuration and helps maintain low inertia for quick acceleration and deceleration. Its electrical ratings reference 240 Vac supplies, matching common servo drive systems used in light industrial equipment. This supply compatibility supports straightforward integration into motion systems that already operate from that voltage class.