Product Description:

The PMB33C-20101-03 is a brushless servomotor manufactured by Pacific Scientific within the PMB Brushless Servomotors series. It is designed for closed-loop positioning and speed control, translating three-phase drive current into mechanical rotation for axes used in material handling, packaging, and general automation. Electronic commutation lets the motor maintain torque without the maintenance associated with brushed designs. Because commutation is handled electronically rather than by brushes, wear at the rotating interface is reduced and routine replacement of contact components is avoided. The flange pattern also matches standardized motion stages for straightforward machine integration.

With a frame classified as NEMA Size 34, the motor mounts to equipment that uses a 3.4-inch square face. At 240 VAC, the winding draws a nominal stall current of 3.8 ARMS, which is the continuous current an amplifier must supply to hold maximum rated torque while the shaft is locked. Rotor position is sensed by a triad of Hall sensors, enabling six-step commutation when high-resolution feedback is unnecessary. This feedback method is commonly used where commutation and basic position reference are required without the added complexity of a higher-resolution encoder. Torque is transmitted through a square key on the output shaft, providing positive engagement with belts, gears, or couplings. Field wiring is simplified because power and feedback conductors exit as flying leads with AMP connectors, so the motor can be wired without a separate motor plug.

For environments with splash or dust, an optional shaft seal protects the front bearing from contamination. An embedded PTC thermistor signals the drive if winding temperature approaches the safe limit. The magnetic circuit uses a stack length multiple of 3, adding axial lamination sections to raise continuous torque without enlarging the mounting footprint. This arrangement increases active magnetic length while keeping the same mounting face, so the motor can provide more continuous output in the same basic envelope.