Product Description:

The PMB31B-10216-03 is a brushless servomotor from Pacific Scientific in the PMB Brushless Servomotors series. As a low-inertia rotary actuator, it converts drive current into precise shaft movement for positioning tasks in industrial automation such as gantry axes, conveyor drives, or pick-and-place heads. The digital encoder on the rear shaft allows the connected controller to close position and velocity loops, while the internal windings support continuous torque generation during stall or dynamic load changes.

The wiring exits as flying leads with MS connectors, allowing quick disconnection during machine service without disturbing permanent cable runs. With a frame built to NEMA Size 34, the motor aligns directly with standard 3.4-inch square mounting footprints. Under a maximum 240 VAC bus voltage, the windings draw a nominal stall current of 2.7 ARMS, a value used for drive sizing and thermal calculations when the shaft is held under load. Rotor position feedback comes from a digital encoder with commutation, so the drive receives both incremental counts and phase information for electronic commutation. The feedback device offers 4096 ppr resolution, supporting fine incremental moves and low-speed stability in servo loops.

To protect against lubricant migration and fine particulate, a shaft seal is fitted at the front bearing. The embedded PTC thermistor supplies the drive with a temperature-dependent resistance signal so the amplifier can limit current if the windings overheat. The output spindle uses a round shaft, making it compatible with clamp couplings or pulley bushings when precise key alignment is unnecessary. Magnetic length is identified by stack-length code 1, which indicates the shortest lamination stack used in this motor family and helps keep mass and inertia low for high dynamic response on lightweight axes.