Product Description:

The PMB31B-00101-03 is a brushless servomotor produced by Pacific Scientific in the PMB Brushless Servomotors series. It converts controlled three-phase electrical power into rotary motion for positioning axes and regulated speed loops in automated machinery. The motor is intended for closed-loop industrial drives that need moderate torque density from a compact package. Because electronic commutation replaces brushes, the design avoids brush wear and supports cleaner operation in continuous industrial service. This layout suits equipment that needs repeatable starts, steady running speed, and accurate response to changing load commands.

Its power interface is provided through flying leads with AMP connectors, which allows direct cable integration without a fixed terminal block. The frame corresponds to NEMA Size 34, so the mounting face matches common 3.4-inch square machine patterns used on mid-range gearheads and brackets. When operated from a 240 VAC supply, the motor holds rotor torque at stall with only 2.7 ARMS of current, which helps limit heat during static operation. Rotor position feedback comes from a Hall sensor, enabling six-step commutation with standard servo amplifiers. Electromagnetic energy is concentrated in a lamination pack identified by the stack length multiple of 1, which keeps inertia and mass low for responsive acceleration.

The motor includes a shaft seal and PTC thermistor, which help limit oil ingress and monitor temperature during overload conditions. Output torque is delivered through a flat shaft end, giving set-screw couplings a positive anti-rotation surface without using a keyway. The thermistor can be used by the control system to detect rising winding temperature before prolonged overload causes excessive heating. These features make the unit suitable for compact motion systems where simple shaft coupling and basic thermal protection are required. The lead arrangement supports orderly cable routing, and the compact frame helps the motor fit assemblies where available mounting space is limited.