Product Description:

The PMB31D-20201-01 brushless servomotor is produced by Pacific Scientific as part of the PMB Brushless Servomotors series. It is a three-phase, permanent-magnet actuator intended to provide repeatable torque and velocity in automated equipment that requires a compact, low-maintenance motion source. By combining an embedded sensor set with direct-wired power leads, the motor simplifies cabinet layout while maintaining the fast response needed in indexing tables, pick-and-place heads, and general material-handling axes. This arrangement also reduces the number of separate components around the axis and helps keep surrounding machine sections uncluttered. It also supports cleaner cable routing where several axes are grouped in a small machine frame.

Mechanical integration is aided by its NEMA Size 34 frame, so the flange and pilot dimensions align with widely available gearboxes and mounting brackets. During locking conditions, the windings can accept a nominal stall current of 5.4 ARMS at up to 240 VAC, a value used to size the power stage and estimate thermal limits under static loads. Rotor position feedback is provided by a Hall sensor, giving the controller commutation signals without an external encoder. Power and signal exit through flying leads with MS connectors; this arrangement speeds assembly because the potted leads absorb vibration while the circular connectors permit quick disconnects. Torque is transferred through a square key shaft end that helps prevent slippage under cyclic loading.

The motor includes a shaft seal, which protects the front bearing against coolant splash and fine particulates encountered on packaging lines. The active magnetic section uses a stack length multiple of 1, so the short lamination stack keeps inertia low and supports quick acceleration during frequent starts and stops. This layout suits compact axes that need responsive motion without a longer motor body. It also helps maintain a shorter overall motor length where clearance behind guards or tooling is limited. The winding insulation and magnetic materials are matched to the motor’s thermal operating range so performance remains stable during normal duty.