Product Description:

The PMB31D-20216-02 is a brushless servomotor produced by Pacific Scientific as part of the PMB Brushless Servomotors series. It combines an integral stator, rotor, and feedback package to provide closed-loop speed and position control to conveyors, pick-and-place axes, and light machine tools. When paired with a compatible drive, the motor converts electrical power into precise mechanical rotation, allowing OEMs to simplify axis design and improve accuracy in distributed automation platforms. Its integrated feedback package lets the drive maintain stable motion during starting, stopping, and reversing.

In physical terms, the motor follows the NEMA Size 34 frame, so its mounting pattern matches standard 3.4-inch square flanges used in compact servo stages. At 240 VAC, the nominal stall current is 5.4 ARMS, indicating the continuous current that can be applied without exceeding thermal limits at standstill. Position feedback is supplied by a 4096 ppr incremental encoder; this resolution allows the controller to detect movement as small as 0.088° per count and refine velocity loops. Power and signal conductors exit the housing as flying leads with MS connectors, providing pigtail flexibility while preserving environmental sealing. Commutation information is embedded within the feedback device because the sensor is a Digital Encoder with commutation, eliminating separate Hall tracks and simplifying wiring.

The mechanical interface uses a square key on the shaft, giving positive drive engagement with pulleys or couplings and preventing slip under peak torque. Thermal monitoring is built in through a PTC thermistor, so the drive can reduce current if the winding temperature rises toward its limit. The motor has a stack length multiple of 1, which is the shortest lamination stack offered in the series; this keeps inertia low for rapid acceleration on short-stroke axes. The unit is produced by Pacific Scientific.