DC Motor Armature Torque Formula |
||
| \( \tau_a \;=\; \dfrac{ 60 \cdot K_a \cdot I_a \cdot \Phi_B }{ 2 \cdot \pi }\) | ||
| Symbol | English | Metric |
| \( \tau_a \) (Greek symbol tau) = Armature Mechanical Torque | \(lbf-ft\) | \(N-m\) |
| \( K_a \) = Motor Constant (Depends on the Armature Design) | - | - |
| \( I_a \) = Armature Current | \(A\) | \(C\;/\;s\) |
| \( \Phi_B \) (Greek symbol Phi) = Armature Magnetic Flux | \(V\;/\;sec\) | \(Wb \;/\; mm^2\) |
| \( \pi \) = Pi | \(3.141 592 653 ...\) | \(3.141 592 653 ...\) |
DC motor armature torque is the rotational force (torque) produced by the armature, which is the rotating part of a DC motor. The armature torque is a critical parameter in determining the motor's ability to perform mechanical work, such as driving a load. In a DC motor, the armature is typically a coil of wire (or a series of coils) wound around an iron core, placed within a magnetic field generated by the motor's field windings or permanent magnets. When current flows through the armature windings, it interacts with the magnetic field, producing a force (based on the Lorentz force principle). This force causes the armature to rotate, generating torque.
Torque is directly proportional to both the armature current and the magnetic flux. If either increases, the torque increases, assuming the other remains constant. The direction of the torque depends on the direction of the current and the magnetic field, following the right-hand rule. The armature torque determines how much mechanical power the motor can deliver to a load, such as turning a wheel or driving a pump.
