Product Description:

The PMB31D-20116-02 is a brushless servomotor built by Pacific Scientific and delivered within the PMB Brushless Servomotors series. It converts three-phase drive power into precise, closed-loop torque for coordinated axes in packaging equipment, pick-and-place arms, and other automated machinery. Integrated electronic feedback allows the connected amplifier to command rapid reversals and position holds without mechanical backlash. The motor is intended for servo systems that need accurate speed changes and stable holding behavior during dwell periods between moves.

The motor uses a NEMA Size 34 frame, giving mounting dimensions that match standard 5.50-inch square face plates used on many gearboxes and linear stages. This makes the housing easy to match with common motion hardware built around that footprint. Continuous force generation is limited by a nominal stall current of 5.4 ARMS, so the paired drive must supply that phase current at up to 240 VAC to hold full static torque without overheating. Rotor position is reported by a 4096 ppr incremental encoder, and this resolution supports sub-degree indexing when the drive interpolates the digital counts. The feedback device is a digital encoder with commutation, so commutation signals are included in the same package and separate Hall tracks are not required. Output torque is delivered through a square key shaft, allowing rigid torque transfer into pulleys or couplings without relying on friction alone.

Field wiring is simplified by flying leads with AMP connectors, so installation uses matching crimped terminations instead of specialized circular plugs. Thermal protection is handled internally by a PTC thermistor, enabling the drive to reduce current if winding temperature rises above its threshold. The electromagnetic section uses a stack length multiple of 1, which indicates the shortest lamination stack available in the platform and helps keep inertia low for rapid acceleration. That short stack favors quick speed changes in applications where low rotor inertia is important to axis response. The unit is a PMB Series Brushless Servomotor and uses winding and connector conventions common to this motor line.