Product Description:

The KA840XXX is a brushless AC servo motor produced by Sanyo Denki as part of the K SANMOTION Servo Motors series. Intended for light-to-medium-duty feed axes, the unit converts regulated DC bus energy into precise shaft rotation for factory robots, semiconductor handlers, and general-purpose positioning stages. A compact stator design, rare-earth magnet rotor, and feedback-ready rear housing provide the electromechanical interface required for closed-loop motion systems in industrial automation.

The motor’s continuous operating point is based on a rated armature voltage of 85 V and a rated current of 5.7 A delivered by the drive amplifier. When those conditions are met, the shaft sustains a rated torque of 1.53 N·m while turning at a rated speed of 2500 rpm, resulting in a mechanical power output of 400 W. Acceleration capability is represented by a rated power rate of 4.7 kW/s, indicating how quickly the motor can increase its mechanical output. A winding resistance of 0.95 Ω and a torque constant of 0.31 N·m/A establish the electrical relationship between phase current and developed torque, while the voltage constant is 32.9 × 10⁻³ V per rpm. Under stalled conditions, the armature can continuously hold 1.70 N·m before the temperature rise exceeds the permitted limit.

For transient demands, the motor offers a peak stall torque of 12 N·m, which can be reached when the drive supplies a peak armature stall current of 40 A. The magnetic field builds quickly because the phase inductance is only 1.5 mH, and the low rotor inertia of 5.0 × 10⁻⁴ kg·m² allows axes to accelerate or reverse rapidly with minimal overshoot. The initial stall current limit of 6.0 A supports brief holding events while keeping the motor within its thermal limits.