Product Description:

The PMB31D-10114-03 is a brushless servomotor built by Pacific Scientific and supplied within the PMB Brushless Servomotors series. By converting commanded phase current into regulated torque, the motor drives positioning tables, pick-and-place arms, and similar automation axes that require accurate starts, stops, and speed changes. Its permanent-magnet rotor and wound stator fit a standard machine envelope, so it can be installed in equipment that uses the familiar NEMA 34 mounting class without extensive mechanical rework. Because it operates as a closed-loop servo, it can correct for changing load conditions when paired with a compatible controller.

The motor’s frame follows the NEMA Size 34 mounting pattern, providing 2.75-inch square face dimensions that match standard gearboxes and clamps. During continuous stall at rated bus voltage, the phase windings carry 5.4 ARMS, so the selected drive must support that current without overheating. Position feedback comes from a 2048 ppr quadrature encoder, and the digital encoder with commutation supplies incremental counts together with commutation tracks, eliminating the need for separate Hall sensors. Field wiring uses flying leads with AMP connectors, allowing power, sensor, and thermistor conductors to terminate directly in a machine junction box or cable harness.

For harsher duty, a factory-installed shaft seal helps protect the front bearing from coolant splash and airborne dust, while the embedded PTC thermistor monitors internal temperature so the controller can respond before insulation is overstressed. The motor uses a round shaft, which works well with compression-style couplings and avoids the stress concentrations associated with keyed output ends in some layouts. A stack length multiple of 1 keeps the rotor comparatively short and light, which supports quick acceleration and deceleration on indexing conveyors and transfer axes. That shorter active stack can also help reduce inertia during frequent reversing moves.