Product Description:

The PMB31D-201YY-10 brushless servomotor is manufactured by Pacific Scientific within the PMB Brushless Servomotors series. As a three-phase permanent-magnet unit, it converts drive current into controlled rotary motion for indexing tables, packaging axes, and other automation loads. It supports repeatable positioning and steady speed regulation in applications that require accurate rotary control.

With a compact housing length of 134.1 mm, the motor fits NEMA Size 34 mounting patterns and uses a stack length multiple of 1, which helps keep weight down while maintaining magnetic volume. Flying leads terminated with AMP connectors simplify wiring, and a square-key shaft transmits torque without slip. At standstill, the motor can deliver 2.11 Nm continuously, and short bursts rise to a peak of 6.26 Nm when 15.3 ARMS is supplied. The nominal stall current at 240 V is 5.4 ARMS, so most mid-range digital drives can operate the unit without oversizing. During rated operation, it develops 6000 rpm at a load of 1.62 Nm, supported by an inductance of 5.2 mH that moderates current ripple and a voltage constant of 26.4 VRMS/kRPM that describes back-EMF behavior. A viscous damping coefficient of 0.0124 Nm/kRPM helps reduce speed droop under light loads.

Electrical parameters include a winding resistance of 2.0 Ohms, which balances copper loss against dynamic response. Rotor inertia is 0.137 × 10⁻³ kg·m², allowing rapid acceleration without causing control loop instability. The motor has an IP40 enclosure rating, so it should be installed in a clean, dry enclosure. Its torque constant of 0.41 Nm/ARMS converts commanded current into predictable shaft torque, and the thermal resistance is 1.08 °C/W during continuous duty.