Product Description:

The PMB31B-10116-03 is a brushless servomotor manufactured by Pacific Scientific as part of the PMB Brushless Servomotors series. It converts regulated three-phase power from a drive into controlled mechanical output so automated axes can index, dwell, or follow coordinated profiles with high repeatability. A brushless design reduces commutation wear, which supports longer service intervals and helps the motor maintain fast response during repeated starts, stops, and speed changes in packaging, material-handling, and assembly equipment across repetitive production cycles.

The motor is built on the NEMA Size 34 frame, giving it a standardized 3.4-inch square mounting face that matches common gearboxes and brackets. Under a 240 VAC bus, the winding can tolerate a nominal stall current of 2.7 ARMS, which marks the continuous torque limit unless added cooling is provided. Field wiring uses flying leads with AMP connectors, eliminating a mating receptacle on the housing and simplifying cable routing in tight panels or enclosed machine spaces. Feedback and electronic commutation are provided by a digital encoder with commutation, and its resolution of 4096 ppr gives the drive detailed position data so small command errors can be corrected quickly during indexing and contouring.

A combined shaft seal and PTC thermistor helps protect internal bearings from contaminants while allowing the drive to monitor winding temperature and respond if excess heat develops. The output uses a round shaft, which suits clamping couplings or pulleys that mount directly on the journal without a keyway. Magnetic stack length is set at a multiple of 1, keeping the rotor compact and helping reduce reflected inertia in high-speed point-to-point moves. This layout supports compact servo axes that rely on direct coupling, stable thermal feedback, and smooth motion during frequent cycling.