Product Description:

The PMB33C-20200-03 is a brushless servomotor from Pacific Scientific in the PMB Brushless Servomotors series. It converts electrical energy into controlled rotary motion for packaging, material-handling, and automated assembly stations where repeatable positioning is required. The motor’s electromagnetic design supplies high stall torque without overheating and supports tight velocity regulation when connected to a compatible drive controller. This operating profile suits servo axes that must accelerate, decelerate, and hold commanded speed with consistent response during repeated machine cycles.

It occupies the NEMA Size 34 frame, so its mounting face and pilot dimensions match other 3.4-inch square motors used on small- to mid-torque axes. Under a 240 Vac supply, the nominal stall current is 3.8 ARMS, indicating the line current the drive must source during locked-rotor torque tests. Power and feedback leave the housing through flying leads with MS connectors, which allow direct cable routing while maintaining a detachable interface at the motor. Rotor position is measured with a resolver, providing feedback that resists electrical noise and supports stable control in demanding industrial environments. These electrical and connection features make the motor easier to integrate with compatible servo amplifiers and feedback circuits already used on multi-axis machinery.

This configuration includes a shaft seal and PTC thermistor. The seal helps limit oil or dust ingress along the shaft, while the thermistor changes resistance as temperature rises so the drive can perform an orderly shutdown near the winding’s thermal limit. A square key is machined into the output shaft to transmit torque to pulleys or couplings without slippage. The lamination stack uses a multiple of 3, increasing magnetic volume for higher continuous torque. This stack length multiple also affects rotor inertia, which can influence acceleration behavior and the way the motor responds to changing load conditions.