Product Description:

The PMB31D-20216-01 brushless servomotor is built by Pacific Scientific and belongs to the PMB Brushless Servomotors series. The motor uses permanent-magnet construction with electronic commutation to deliver bidirectional torque under closed-loop control. Within industrial automation, it drives indexing tables, material-handling axes, and light machine tools where repeatable positioning and compact mounting envelopes are required.

Mechanically, the frame conforms to NEMA size 34, providing a 3.4-inch square flange that matches common servo and stepper layouts. The nominal stall current of 5.4 ARMS at 240 VAC is the continuous phase load the amplifier must sustain while the rotor is locked, and it sets the baseline for drive sizing and cable ampacity. Motion feedback is delivered by a 4096 ppr incremental encoder, translating to 4,096 counts per revolution for sub-degree resolution in velocity or position loops. Power, feedback, and Hall commutation lines exit as flying leads with MS connectors, so the motor can be wired quickly to panel-mounted bulkhead receptacles without additional soldering. The sensing arrangement uses a digital encoder with commutation, furnishing three evenly spaced Hall signals to synchronize the inverter's switching sequence.

The output shaft is machined with a square key that mates to keyed hubs, preventing rotational slip under peak torque. A factory-installed shaft seal sits behind the front bearing to reduce the ingress of coolant or fine dust into the interior. The magnetic core employs a stack length multiple of 1, indicating the shortest lamination set in the family and resulting in lower rotor inertia for faster step-and-settle times. The unit maintains insulation ratings, winding materials, and thermal characteristics that are consistent with other members of the series.