Torque and torque of the motor

As a key equipment in modern industrial production, electric motors can convert electrical energy into mechanical energy and drive the operation of various mechanical equipment. During the operation of electric motors, two physical quantities, namely torque and torsion, have a direct impact on their rotational speed and power output. This article will expound the basic concepts of motor rotational dynamics, with a focus on analyzing torque and torsion, to help readers understand the working principles and performance characteristics of electric motors.

I. Basic Concepts of Motor Rotational Dynamics
Electric motors achieve the conversion from electrical energy to mechanical energy based on electromagnetic induction and Lorentz force. They consist of a stationary stator and a rotatable rotor. When current passes through the stator coils, a magnetic field will be generated, and this magnetic field interacts with the magnetic field of the rotor to produce a moment that drives the rotor to rotate. The rotational speed and direction of the electric motor are influenced by this moment, so the moment is of crucial importance in the process of motor rotation.
In electric motors, the magnitude of the moment depends on the magnitude and direction of the current, the strength and direction of the magnetic field, as well as the position and rotational speed of the rotor. Meanwhile, the rotational speed and power output of the electric motor are also affected by it. It can be seen that the moment is one of the key indicators for measuring the performance of electric motors.

II. Torque and Torsion of Electric Motors
In the field of electric motors, the moment has two expressions, namely torque and torsion. Torque is often used to describe the moment generated during the rotation of the electric motor, while torsion is used to describe the moment generated when the electric motor is twisting.
(A) Torque
Torque refers to the moment generated during the rotation process of the electric motor, and its unit is Newton-meter (Nm). Its magnitude is related to the input current and output rotational speed of the electric motor. The formula is: Torque = Dynamic Torque × Transmission Efficiency. The dynamic torque is the moment generated by the electric motor. Since the transmission efficiency generally exceeds 90%, the torque is mainly determined by the dynamic torque.
(B) Torsion
Torsion is the moment generated when the electric motor is twisting, and its unit is also Newton-meter (Nm). The magnitude of the torsion depends on the input current and output rotational speed of the electric motor. The calculation formula is: Torsion = Static Torque × Transmission Efficiency. The static torque is the torsion generated by the electric motor. Due to the relatively high transmission efficiency, the torsion is mainly determined by the static torque.

III. The Relationship between Torque and Torsion of Electric Motors
In terms of physical meaning, both torque and torsion represent the magnitude of the moment generated by the electric motor. However, in practical applications, the two have different expressions. When selecting and designing electric motors, torque is often used to evaluate the performance of electric motors; in mechanical transmission systems, torsion is the main indicator for measuring the performance of the transmission system.
In practical applications, there is a 1:1 conversion relationship between torque and torsion, that is, 1 Newton-meter of torque is equivalent to 1 Newton-meter of torsion, and they can be converted to each other as needed.