Product Description:

The PMB31D-20100-03 is a brushless servomotor manufactured by Pacific Scientific as part of the PMB Brushless Servomotors series. Designed for automated equipment, the motor converts three-phase power into precisely regulated rotary motion and returns feedback so the drive can close the position and speed loops. In material handling, pick-and-place, or light machining stations, the unit provides repeatable torque at low inertia, enabling quick indexing and accurate stops with predictable settling behavior after each programmed cycle. Its construction follows NEMA size conventions and accepts custom sealing options, allowing integration into enclosed or ventilated machinery where compact servo packaging is required.

At rated conditions, the motor draws a nominal stall current of 5.4 ARMS from a 240 VAC drive; this value is the continuous phase current required to hold the rotor locked without exceeding thermal limits. The frame follows the NEMA Size 34 outline, meaning the mounting face measures 3.4 inches square and aligns with standard U.S. servo brackets. Power and feedback exit the housing through flying leads with AMP connectors, allowing crimp-style termination instead of fixed plugs, which simplifies cable routing inside moving carriages. Rotor position is reported by a resolver, an analog transducer that withstands vibration better than optical encoders while still supplying fine sine-cosine feedback for digital drives.

The unit ordered under the customization code provides a shaft seal and PTC thermistor; the seal limits lubricant escape at the output, while the thermistor provides an overtemperature signal to the drive. Torque is transmitted through a square key machined into the 0.500-inch shaft, a connection that aligns with keyed pulleys or couplings. The motor uses a stack length multiple of 1, which is the shortest lamination set available in this frame and the lightest inertial option for this motor size. The short lamination stack reduces rotating mass, which helps the motor respond quickly during frequent start-stop moves.