Motor (commonly known as "motor") refers to an electromagnetic device that converts or transmits electric energy according to the law of electromagnetic induction. It is indicated by the letter M in the circuit. Its main function is to generate driving torque, as the power source of electrical appliances or various machines. The generator is represented by the letter G in the circuit. Its main function is to convert electrical energy into mechanical energy.
The motor mainly consists of an electromagnet winding or distributed stator winding used to generate magnetic field, a rotating armature or rotor and other accessories. Under the action of the rotating magnetic field of the stator winding, the current in the armature squirrel cage aluminum frame passes through and is subject to the action of the magnetic field to make it rotate.
Stator (stationary part)
Stator core: part of the magnetic circuit of the motor, on which the stator winding is placed;
Stator winding: it is the circuit part of the motor, which is connected with three-phase alternating current to generate a rotating magnetic field;
Base: fix the stator core and front and rear end covers to support the rotor and play the role of protection and heat dissipation;
Rotor (rotating part)
Rotor core: as a part of the magnetic circuit of the motor and the rotor winding is placed in the core slot;
Rotor winding: cut the stator rotating magnetic field to generate induced electromotive force and current, and form electromagnetic torque to make the motor rotate;
DC motor
DC motor is a rotating motor that converts DC electrical energy into mechanical energy (DC motor) or mechanical energy into DC electrical energy (DC generator). It is a motor that can realize the mutual conversion of DC electric energy and mechanical energy. When it operates as a motor, it is a DC motor, which converts electrical energy into mechanical energy; When operating as a generator, it is a DC generator that converts mechanical energy into electrical energy.
Stepper motor
Stepping motor is an open-loop control element stepping motor that converts electrical pulse signal into angular displacement or linear displacement. Under the non overload condition, the speed and stop position of the motor only depend on the frequency and number of pulses of the pulse signal, and are not affected by the load change. When the stepping driver receives a pulse signal, it drives the stepping motor to rotate a fixed angle in the set direction. The angular displacement can be controlled by controlling the number of pulses to achieve accurate positioning; At the same time, the speed and acceleration of the motor can be controlled by controlling the pulse frequency to achieve the purpose of speed regulation.
Working principle of stepping motor
When the current flows through the stator winding, the stator winding generates a vector magnetic field. The magnetic field will drive the rotor to rotate for an angle, so that the direction of a pair of magnetic fields of the rotor is consistent with that of the stator. When the vector magnetic field of the stator rotates by an angle. The rotor also rotates an angle with the magnetic field. Each time an electric pulse is input, the motor rotates at an angle to advance one step. Its output angular displacement is proportional to the number of input pulses, and its speed is proportional to the pulse frequency. Change the order in which the windings are energized, and the motor will reverse. Therefore, the number and frequency of control pulses and the energizing sequence of each phase winding of the motor can be used to control the rotation of the stepping motor.
Unidirectional asynchronous motor
Asynchronous motor, also known as induction motor, is an AC motor that generates electromagnetic torque by the interaction of air gap rotating magnetic field and rotor winding induced current, thus realizing the conversion of electromechanical energy into mechanical energy.
Working principle of single-phase asynchronous motor
In the AC motor, when the stator winding passes through the AC current, the armature magnetomotive force is established, which has a great impact on the energy conversion and operation performance of the motor. Therefore, single-phase AC winding is connected to single-phase AC to generate pulsating magnetomotive force, which can be divided into two rotating magnetomotive force sums with equal amplitude and opposite speed, thus establishing forward and reverse magnetic field sums in the air gap. These two rotating magnetic fields cut the rotor conductor and generate induced electromotive force and induced current respectively in the rotor conductor.
The current interacts with the magnetic field to generate positive and negative electromagnetic torque. The forward electromagnetic torque attempts to make the rotor rotate forward; Reverse electromagnetic torque attempts to reverse the rotor. The superposition of these two torques is the resultant rotation that drives the motor to rotate.
Permanent magnet motor
Permanent magnet motor is a motor that uses permanent magnet to provide magnetic field. Motor work requires two conditions, one is the presence of magnetic field, the other is the presence of moving current in the magnetic field.