Product Description:

The PMB31B-20216-03 belongs to the PMB Brushless Servomotors series manufactured by Pacific Scientific. This brushless servomotor is intended for closed-loop industrial automation where repeatable torque and position control are required. By pairing stator windings with a permanent-magnet rotor, it delivers responsive motion while eliminating brush maintenance common to older DC designs. Integrators typically mount this motor to indexing tables, gantry axes, or packaging stations that depend on fine incremental moves coordinated by a drive amplifier.

The frame follows the NEMA Size 34 dimensional standard, so its face and pilot fit readily into machinery that already uses 34-frame steppers or brushless units. When powered from a 240 VAC drive, the motor can hold rated torque while drawing a nominal stall current of 2.7 ARMS, a figure that guides fuse sizing and thermal modeling. Power and feedback exit the housing through flying leads with MS connectors; this hybrid arrangement allows quick line-side disconnection while letting the harness be routed through tight cable tracks. Rotor position is detected by a 4096 ppr incremental encoder, and its Hall tracks supply commutation signals through the same feedback channel. That sensor package is specified as a digital encoder with commutation, simplifying wiring because no separate resolver or Hall board is required.

An added shaft seal and PTC thermistor protect the bearings from contamination and report winding temperature to the drive so current can be limited before insulation thresholds are reached. Output torque is transferred through a square key machined into the shaft, providing positive lock with pulleys or couplings. The active iron stack is a single section, noted as stack length multiple 1, which keeps inertia low and shortens acceleration times.