Product Description:

The PMB31B-00101-01 is a brushless servomotor manufactured by Pacific Scientific for the PMB Brushless Servomotors series. It converts electrical energy into precisely controlled torque and speed, allowing motion axes in industrial automation cells to position loads accurately during repeatable machine movements. The brushless design avoids the brush wear and routine maintenance associated with brushed motors. It is typically used with an electronic drive that regulates current in response to motion commands from the control system.

This motor is built on a NEMA Size 34 frame, so its mounting face and bolt circle match other 3.4-inch devices commonly used on medium-duty machinery. A nominal stall current of 2.7 ARMS at 240 VAC indicates the continuous drive current that the amplifier must supply when the rotor is locked but fully energized. Rotor position feedback comes from a 3-phase Hall sensor, enabling six-step electronic commutation and basic velocity estimation throughout rotation. Power and feedback conductors exit the housing as flying leads, allowing direct routing through cable trays or conduits instead of a fixed connector interface. This arrangement can also help when the motor is installed where connector clearance is limited.

A pair of AMP connectors is pre-installed on the flying leads, which supports quick connection to mating harnesses. The shaft end has a flat, providing a simple drive surface for set-screw couplings when backlash requirements are moderate, and an optional shaft seal helps limit lubricant loss and keeps fine particulate away from the front bearing. The motor uses a stack length multiple of 1, which gives it the lightest magnet stack available in this product line and helps keep reflected inertia low on high-speed axes. It also shares winding data and thermal characteristics with related units in the family.