Product Description:

The PMB31B-20216-01 is a brushless servomotor produced by Pacific Scientific and supplied within the PMB Brushless Servomotors series. As a permanent-magnet motor, it supports closed-loop torque and position control for indexing tables, pick-and-place heads, and other motion axes that require repeatable accuracy in industrial automation. The brushless design eliminates brush wear and supports cleaner operation in automated equipment that runs frequent start-stop cycles. When paired with a compatible drive, the motor can respond quickly to command changes while maintaining stable motion under varying loads.

The motor frame is classified as NEMA Size 34, which uses a standardized 3.4-inch square flange that fits common mounting patterns. During a locked-rotor condition at 240 VAC, it draws a nominal stall current of 2.7 ARMS. That current value helps the connected amplifier stay within its current limit during heavy starting or stalled conditions. Feedback is provided by a resolver-based digital transducer with 4096 ppr of incremental resolution, enabling tight servo loops with minimal following error. Because the sensor uses a digital encoder with commutation, separate Hall devices are unnecessary and commutation data is carried in the feedback stream. Mechanical power is transmitted through a shaft with a square key, allowing direct coupling to pulleys or gear sets without relying on friction alone.

Electrical terminations use flying leads with MS connectors, which allow the cable set to pass through conduit before the circular connectors are attached. This lead style helps reduce bulk at the motor housing and can simplify cable routing in compact assemblies. An integrated shaft seal helps keep lubricants in and airborne contaminants out when the motor is mounted in washdown or dusty areas. Magnetic output comes from a stack length multiple of 1, so thermal mass remains moderate and response stays quick during repeated indexing moves.