Product Description:

The PMB31B-00114-01 is a brushless servomotor produced by Pacific Scientific within the PMB Brushless Servomotors series. In industrial automation, it converts commanded current into regulated torque and speed for precise positioning and steady velocity in packaging stations, small gantries, and electronic assembly cells. A permanent-magnet rotor and electronic commutation support fast response with low cogging during closed-loop motion. Its compact housing also helps the motor fit into machine spaces where installation room is limited, and brushless operation avoids wear associated with physical commutators.

Power, feedback, and commutation signals exit through flying leads with AMP connectors, so wiring can be completed without specialized plugs. The motor uses a NEMA Size 34 frame with a 3.4-inch square flange that aligns with common reducers and face-mount brackets. The built-in optical encoder supplies 2048 ppr of incremental resolution, giving the controller fine position feedback during slow-speed motion, short indexing moves, and repeatable reversals. During locked-rotor conditions, the windings draw a nominal stall current of 2.7 ARMS at 240 VAC, which sets the continuous current level the drive must handle thermally. Rotor position and phase information are provided by a digital encoder with commutation, which avoids the need for separate commutation hardware. This signal arrangement helps a compatible drive maintain smooth startup and stable control across a broad operating range.

An optional shaft seal helps block coolant and dust at the output end when the motor is installed near washdown areas or contaminated process zones. The shaft includes a flat that gives set screws a positive seating area and helps limit slip under cyclic loading. A stack length multiple of 1 indicates a single magnetic lamination section, which helps keep rotor inertia low for rapid acceleration of lightweight loads. That lower inertia is useful on compact axes that need frequent starts and stops without sluggish response. The shaft geometry also supports direct attachment to simple couplings or hubs in space-limited mechanisms.