Product Description:

The PMB31B-20216-00 is a brushless servomotor manufactured by Pacific Scientific and supplied in the PMB Brushless Servomotors series. It provides closed-loop rotational power for positioning and speed-regulated axes in packaging, material-handling, and semiconductor tools. The motor works with an external servo amplifier that energizes its three-phase windings and reads integrated feedback so commanded motion profiles can be followed with minimal error under changing load conditions. This arrangement supports accurate starts, stops, and speed changes in automated equipment that depends on repeatable axis motion.

The motor uses a frame classified as NEMA Size 34, which sets the flange pattern and pilot diameter for standardized mounting. Continuous torque delivery is supported by a nominal stall current of 2.7 ARMS when the connected drive operates at its rated supply ceiling, and this current marks the thermal limit for holding torque at zero speed. A rotary feedback element with a resolution of 4096 ppr combines with a digital encoder with commutation output, allowing the drive to align phase currents precisely throughout each revolution. This feedback arrangement helps the amplifier maintain smooth low-speed motion, steady position control, and accurate current phasing during repeated index moves.

Torque is transferred through a square key shaft that drives pulleys or couplings without slippage. Power and feedback exit the housing through flying leads with MS connectors, eliminating the need for an on-motor terminal box and helping the motor fit spaces where rigid connector bodies would reduce clearance. The motor uses a stack length multiple of 1, which helps keep inertia low for quick acceleration and deceleration. It is supplied as a standard motor for operation on a 240 VAC bus. This combination suits compact servo axes that need responsive motion without a longer magnetic stack.