Product Description:

The S31GNNA-RNVM-00 is a 6-pole Neodymium magnet brushless servo motor manufactured by Pacific Scientific for the S Brushless Motors series. Built on the NEMA frame standard, it mounts directly to common U.S. mechanical interfaces, which simplifies retrofits. In industrial automation, it converts commanded drive current into precise rotary motion for indexing tables, gantry axes, and pick-and-place heads. Position feedback is supplied by a size 21 frameless resolver integrated into the stator, so a controller can close the loop without relying on any secondary sensor.

With a continuous stall capability of 2.2 Nm, the motor can hold a static load indefinitely within its thermal limits, while a peak output of 6.2 Nm supports fast acceleration profiles. A torque constant of 1.3 Nm/ARMS indicates how much phase current is required for each newton-meter of output torque. The electromagnetic time constant is influenced by a line-to-line inductance of 41.2 mH, which limits current ripple and affects control-loop bandwidth. Mechanical interchangeability is provided by the NEMA 34 frame outline, which aligns the pilot diameter and bolt circle with legacy stepper or induction motor packages.

Additional electrical parameters include a phase resistance of 16.4 Ω, which governs copper losses during continuous duty, and a back-EMF constant of 0.82 VRMS/rad/sec, which allows the drive to predict generated voltage during dynamic braking. The rotor’s reflected inertia is only 0.18 ×10⁻³ kg·m², enabling rapid reversals with minimal servo gain adjustment, and the overall mass of 3.2 kg eases installation on lightweight machine axes. The unit is supplied without a holding brake, and a Viton shaft seal guards the bearings from coolant splash. The design also includes one lamination stack, a G winding code, a motor-mounted MS connector, and no secondary feedback.