Product Description:

The PMB33F-20201-01 is a brushless servomotor built by Pacific Scientific as part of its PMB Brushless Servomotors series. Intended for tightly regulated rotary axes, this motor generates responsive torque while maintaining speed accuracy. It is suitable for pick-and-place gantries, packaging machinery, and automated assembly lines where compact size and electrical efficiency are required.

The motor’s electrical and mechanical interface affects mounting and wiring requirements. Power and feedback cabling exits as flying leads terminated in rugged MS connectors, eliminating the need for an integral plug and supporting straightforward cable routing. The NEMA Size 34 frame conforms to a 3.4-inch square face and standardized pilot diameter, so the motor can bolt onto existing brackets without redrilling. At the rated bus voltage, the nominal stall current reaches 11.0 ARMS, which is the continuous phase current the servo amplifier must deliver to keep the shaft stationary at rated load. Rotor position is relayed by an internal Hall sensor arrangement, which produces logic-level signals spaced 120 electrical degrees apart and enables conventional six-step commutation.

Mechanical power is transmitted through a square key machined into the output shaft, providing rotational lock between the motor and the driven element during reversing or braking. To achieve higher continuous torque without enlarging the frame, the stator uses a stack length multiple of 3, which adds active lamination sections and increases magnetic flux capacity. For installations exposed to coolant spray or airborne particulates, a configurable shaft seal can be specified to restrict ingress at the front bearing. The electrical geometry targets systems supplied from 240 VAC. This allows direct connection to commonly available single-phase or three-phase servo drives.