DC servo motors adopt a slender armature structure, with a rotational inertia of only 1/3 to 1/2 that of ordinary DC motors , and their mechanical strength can withstand high acceleration impacts. Permanent magnet models use permanent magnet materials for excitation, combining high magnetic energy density and low hysteresis loss. Low inertia models reduce rotational inertia and improve response speed through optimized rotor design. Brushes are precisely placed on the geometric neutral plane to ensure symmetrical forward and reverse rotation characteristics.
Basic Principle: The energized rotor rotates under the Lorentz force in the stator magnetic field. The torque formula is:
$$T = K_t \cdot I$$ where $K_t$ is the torque constant (typical value 0.01~0.1 N·m/A), and $I$ is the armature current.
Closed-loop control process: The controller compares the target position with the actual feedback signal (such as encoder data); the PWM drive voltage is adjusted through a PID algorithm to dynamically correct the motor speed and direction; the response time can be as short as 1ms, and the positioning accuracy reaches ±0.01° (data source: Yaskawa Electric technical documents).