Product Description:

The PMB31B-00101-00 is a brushless servomotor produced by Pacific Scientific and belongs to the PMB Series Brushless Servomotor line. It is intended for positioning and speed control duties in industrial automation where accurate torque delivery and a compact footprint are required. A NEMA 34 frame allows straightforward interchange with other motors that follow this mounting standard. The assembly integrates Hall-effect feedback so a drive can detect rotor position during startup and commutation, which supports controlled response as the motor begins to turn.

The motor’s frame size is NEMA Size 34, which matches common gearboxes and linear stages used with this mounting pattern. Power exits the housing through flying leads with AMP connectors, and these pre-terminated pigtails help maintain reliable electrical contact in vibrating machines. The winding can generate a nominal stall current of 2.7 ARMS, so the matching drive must support that current level without exceeding thermal limits. That current capability also affects the torque the motor can deliver while holding position or accelerating a load. Rotor position is detected by a three-phase Hall sensor, giving six commutation states per electrical revolution so low-speed control remains stable. A flat shaft provides a simple contact surface for set-screw couplings when moderate torque transfer is required.

The motor is supplied in the standard motor configuration, so it does not include special winding or enclosure options. Its electromagnetic section uses a stack-length multiple of 1, which gives the shortest active core in the series and helps reduce inertia during rapid acceleration. This shorter magnetic stack is useful in compact axes where quick speed changes are more important than maximum rotor mass. The motor is rated for use on 240 VAC, and the amplifier must support the required current while maintaining acceptable winding temperature during continuous operation.