Product Description:

The PMB31B-00116-03 is a brushless servomotor manufactured by Pacific Scientific and supplied within the PMB Brushless Servomotors series. As a rotary actuator, it converts electrical energy into precisely regulated torque and speed, allowing closed-loop motion control on packaging tables, conveyors, or small gantry axes. The motor uses a NEMA Size 34 frame, so its flange and pilot dimensions match standardized 3.4-inch square mountings used on many compact motion systems. Continuous torque at zero speed is achieved with a nominal stall winding current of 2.7 ARMS when the windings are supplied from a 240 VAC drive. This current level indicates the output the matching amplifier must supply when the motor is held at stall.

Feedback for commutation and position is supplied by a 4096 ppr incremental encoder, providing 12-bit resolution to the controller for smooth velocity control and accurate indexing. The sensing element is a digital encoder with commutation, and three embedded Hall tracks align the sinusoidal currents with the rotor’s magnetic field without requiring external Hall boards. This arrangement gives the controller rotor orientation and position feedback in one package, which helps stabilize low-speed operation and repeatable moves. A flat shaft end simplifies rigid coupling to gears or pulleys and helps prevent rotational slip during repetitive start-stop cycles.

Power and signal conductors leave the housing as flying leads with AMP connectors, allowing mating parts to be routed directly through cable chains without bulky backshells at the motor exit. This cable style reduces connector bulk at the housing and helps routing where enclosure space is limited. The motor includes a shaft seal and PTC thermistor; the seal helps block coolant splash or fine dust from the front bearing, while the thermistor reports winding temperature for drive-controlled derating. The magnetic core uses Stack Length Multiple 1, which indicates a single lamination stack and helps keep inertia low for rapid acceleration.