Product Description:

The PMB31B-20200-00 is a brushless servomotor manufactured by Pacific Scientific and assigned to the PMB Brushless Servomotors series. Designed for industrial motion loops, the unit converts three-phase drive power into tightly regulated rotation for pick-and-place axes, small material-handling stations, and light machine tools. Its brushless design avoids commutator wear and supports stable operation in repeat-cycle automation. The motor uses rare-earth magnets on the rotor and distributed windings in the stator, which helps the drive maintain precise speed and torque control while keeping position error low during load fluctuations.

The frame corresponds to NEMA Size 34, so its flange and pilot dimensions match standard 3.4-inch square mounts used on many gearheads and linear stages. Power exits through flying leads with MS connectors, which supports quick disconnection and orderly cable routing inside a cabinet harness. Continuous stall torque is associated with a current of 2.7 ARMS at a maximum of 240 VAC, so the matching drive must be able to supply that current. A built-in resolver tracks shaft position over 360 mechanical degrees for commutation and servo-loop feedback, and mechanical coupling is provided through a square key on the output shaft to reduce slippage during startup or braking torque spikes.

This unit is the Standard Motor version, so no special windings or seals change the usual thermal or dimensional baseline for this model. The electromagnetic section uses a stack length multiple of 1, which keeps inertia low for rapid acceleration while still using the full NEMA 34 frame. That shorter magnetic stack supports quick response in applications that favor low inertia over higher continuous torque. Because no special winding or sealing option is indicated, the motor remains in the standard configuration for this model line.