Product Description:

The PMB31D-20214-02 is a brushless servomotor manufactured by Pacific Scientific for the PMB Brushless Servomotors series. This unit conforms to the NEMA 34 frame class and is intended to deliver controlled torque and speed to indexing heads, pick-and-place modules, and other motion axes that require fast response and repeatable positioning. Used with a matched power stage, it supplies servo-grade rotation by combining an internal permanent-magnet rotor, feedback electronics, and industrial connectors into a single packaged assembly that mounts on standard 86 mm motor flanges.

The connector arrangement uses flying leads with MS connectors, allowing the motor to be wired directly into harnesses without additional junction boxes, while the military-style plugs maintain signal integrity under vibration. Inside the housing, an incremental encoder delivers 2048 ppr resolution so the drive can calculate position to 0.18° per count. The mounting face and shaft height match common gearboxes and actuators. When energized by a 240 VAC servo amplifier, the winding can sustain a nominal stall current of 5.4 ARMS, indicating the continuous current level that can be applied without exceeding thermal limits during static load holding.

Feedback commutation is derived from a digital encoder with commutation, so electrical phase information reaches the drive without separate Hall sensors, simplifying cable runs and improving startup torque linearity. The output shaft is machined with a square key to transmit torque to pulleys or couplings while preventing slip under peak loads. Winding temperature is monitored by a PTC thermistor; when its threshold is reached, the drive can reduce current to protect insulation. The motor is built on a single-stack magnetic core with stack length multiple 1, which keeps axial length short for compact machinery.