Product Description:

The PMB31B-20100-01 is a brushless servomotor manufactured by Pacific Scientific in the PMB Brushless Servomotors series. Intended for industrial automation, the unit converts electrical power into controlled rotary motion so that indexing tables, packaging stations, or light gantry axes can follow precise velocity and position commands from a drive controller. Its brushless design supports repeatable motion with reduced maintenance compared with brushed motor arrangements. The motor is suited to applications that need stable response during frequent starts, stops, and speed changes.

Its frame is classified as NEMA Size 34, which corresponds to a 3.4-inch square mounting face that matches many standard gearheads and brackets. This format helps the motor fit existing machine layouts without requiring special mounting hardware. When the motor is held in a locked condition at 240 V AC maximum bus voltage, the winding draws a nominal stall current of 2.7 ARMS, which helps set amplifier current limits during static holding or low-speed torque production. Rotor position feedback is provided by a resolver, allowing the drive to read rotor angle even through electrical noise or high temperatures. Torque is transferred through a square key machined in the shaft, giving a direct mechanical interface for couplings or pulleys. Power, feedback, and protective earth conductors leave the housing on flying leads with AMP connectors, which simplifies wiring because no mating receptacle is required on the motor shell.

The motor can be ordered with an optional shaft seal so the front bearing area resists oil spray or fine dust in process equipment. The electromagnetic section uses a stack length multiple of 1, indicating a single-stack construction. That arrangement keeps inertia low for rapid acceleration while maintaining the thermal surface area needed for continuous duty. It also helps the motor balance quick axis response with steady heat dissipation during extended operation.