Product Description:

The PMB31B-10201-01 is a brushless servomotor manufactured by Pacific Scientific and included in the PMB Brushless Servomotors series. It is a permanent-magnet, three-phase unit intended to generate precise rotary motion for automated pick-and-place devices, light conveyors, and electronic assembly tooling. By using electronic commutation, it eliminates brush wear and allows clean torque production over repeated cycles. In an industrial automation cell, the motor is typically driven by a compatible digital amplifier that regulates current from feedback signals, allowing fast acceleration, exact speed control, and stable holding torque when the axis is at rest.

Mechanical interchangeability is provided by the NEMA Size 34 frame, which fixes the front-face bolt pattern and pilot diameter so the motor can fit legacy stepper or servo mounts without redrilling. Power and feedback connections use flying leads with MS connectors, which speeds installation and preserves shielding continuity along the cable run. At 240 VAC, the nominal stall current is 2.7 ARMS, which is the continuous current the drive must supply to hold maximum rated torque at zero speed without overheating. Rotor position is detected with a Hall sensor, giving the drive three commutation signals for six-step energizing throughout each electrical cycle.

Application-specific features concentrate on shaft and stack geometry. A round shaft simplifies coupling to timing pulleys or flexible bellows couplings and reduces stress concentrations that square or keyed profiles may introduce. The factory-applied shaft seal blocks oil mist and fine dust from entering the front bearing cavity, which helps extend lubrication life in packaging or food-processing environments. Magnetic length uses a stack length multiple of 1, which helps keep rotor inertia low for rapid indexing and short settling times. That short stack is useful on light-duty axes that require frequent starts and stops.