Product Description:

The PMB31B-00201-02 is a brushless servomotor produced by Pacific Scientific and supplied within the PMB Brushless Servomotors series. It is intended for closed-loop motion tasks where compact direct-drive torque is required, such as positioning tables, small pick-and-place heads, or indexing mechanisms in automated assembly. In these systems, the motor converts controlled electrical power from the drive into precise mechanical rotation, reducing backlash associated with geared solutions and maintaining repeatable axis accuracy under rapid cycling. Because it is brushless, there are no commutator brushes to wear, which supports clean operation during repetitive duty. The motor is well suited to short-cycle motion where fast response and repeatable stopping are more important than peak output power.

This model uses a NEMA Size 34 frame, so its flange and pilot dimensions match standardized 86 mm mounting patterns common on small gantries and conveyors. Power exits the housing through flying leads with MS connectors, which support straightforward connection without soldering. When the shaft is blocked at the rated winding temperature, the drive may deliver up to 2.7 ARMS of stall current at 240 VAC. That current level marks the continuous torque limit and indicates the thermal load placed on the installation. Rotor position feedback is delivered by a three-phase Hall sensor system, providing six commutation states per electrical cycle for trapezoidal current control. Thermal protection is built in with a PTC thermistor that changes resistance sharply near the allowable winding temperature, enabling the drive to reduce current before insulation limits are exceeded.

The output shaft has a flat, which gives pulleys and clamping hubs a simple contact surface for torque transfer while keeping the motor compact. The mechanical stack uses a multiple of 1, which helps keep inertia low and supports quick starts and stops in short indexing moves. Cable routing and mounting proportions stay consistent within the PMB Brushless Servomotors line, and the unit uses a compact motor format suited to dense machine assemblies. This layout leaves room for nearby belts, guards, and sensor brackets in tight automation modules.