Product Description:

The PMB31B-10216-02 is a brushless servomotor designed and manufactured by Pacific Scientific for motion-control axes that require accurate speed and position regulation. As a member of the PMB Brushless Servomotors series, the unit works with digital servo drives to provide closed-loop torque in packaging lines, semiconductor tooling, and material-handling cells. Its electromagnetic design supports rapid reversals and stable torque at low speed, which helps axes respond quickly during indexing and positioning moves. This also makes the motor suitable for repetitive duty where consistent motion is required across frequent starts, stops, and direction changes.

Its nominal stall current is 2.7 ARMS at 240 VAC, so the connected drive must be sized for continuous operation without overcurrent trips. The motor uses a NEMA Size 34 frame, which simplifies fitment with compatible mounting hardware and gearheads. Accurate feedback comes from an incremental encoder rated at 4096 ppr, giving the control loop fine position resolution. A digital encoder with commutation signal set provides incremental position data together with the Hall tracks required for electronic phase switching. Power and feedback exit through flying leads with MS connectors, which allows external connections without opening the motor housing. This feedback arrangement helps the servo amplifier maintain stable commutation and accurate position tracking during both low-speed moves and higher-speed travel.

A factory-installed PTC Thermistor is embedded in the stator winding, where its resistance rises sharply as temperature approaches the allowable limit and enables the drive to reduce current before the insulation is overstressed. This thermal monitoring helps protect the motor during repeated acceleration and dwell periods where winding heat can build faster than the housing can dissipate it. The output shaft has a round profile, so couplings or pulleys can be clamped or press-fit without keyway alignment concerns. Magnetic flux is produced by a single lamination stack, reflected by the stack length multiple of 1, which helps keep rotor inertia low for faster acceleration and deceleration.