Product Description:

The PMB33E-20201-03 is a brushless servomotor built by Pacific Scientific in the PMB Brushless Servomotors series. As a permanent-magnet synchronous unit, it is intended for feedback-controlled positioning and speed regulation tasks common in automated conveyors, pick-and-place stations, and light machine tools. By eliminating brush wear and using electronic commutation, the motor provides clean torque delivery suited to 24-hour duty when matched to a compatible drive. Its compact footprint helps in retrofit projects where space is limited, and its design helps limit cogging and acoustic noise.

The motor uses a NEMA Size 34 frame, making it interchangeable with standard 3.4-inch square mounting patterns often found on legacy steppers. At full excitation, the windings draw a nominal stall current of 7.4 ARMS at 240 VAC, which indicates the continuous current the amplifier must supply to hold position under rated load. Power and feedback conductors exit as flying leads with MS connectors, so cabinet wiring can be completed without soldering or crimp tools. Rotor position information is furnished by a three-phase Hall sensor set that delivers 120-electrical-degree commutation cues to the drive. Output torque is transmitted through a square key on the shaft, allowing rigid coupling to pulleys or gears without relying on friction alone.

Performance is further shaped by a stack length multiple of 3, meaning the magnetic lamination pack is tripled relative to the base segment to raise torque density while maintaining the same frame outline. Environmental and thermal protection comes from a customized shaft seal and PTC thermistor. The seal helps block coolant or dust at the shaft opening, and the thermistor signals the drive if winding temperature approaches an unsafe level. These features allow the motor to operate in tighter enclosures and under variable duty cycles without external sensors.