1. Basic information

Benefits DC Motor (DC Motor) is relatively simple in terms of speed control, only the size of the control voltage has a total speed can be controlled, but the motor is not operating at such a high temperature, flammable environment, and because the motor brushes need to as a current transformer (Commutator) components (brush motor), so they need regular cleaning of the brushes dirt friction generated. The brushless motors called brushless motor, relative to the brush, brushless motor brushes because the less friction with the shaft and therefore more energy is relatively quiet. Higher difficulty level, the price is higher. AC motor (AC Motor) can be at high temperatures, flammable operating environment, and do regular cleaning brushes the dirt, but in the speed control is more difficult, because the need to control AC motor speed control AC frequency (or use induction motor, by way of increasing the internal resistance, at the same frequency of alternating current to reduce motor speed), the control voltage will only affect the motor torque. General civilian motor voltage 110V and 220V of two other industrial applications as well, such as 380V or 440V patterns.

2, the working principle

Rotation of the motor based on the principle of Fleming's left-hand rule, when a wire is placed in the magnetic field, if current flows through the wire, the wire will cut the wires to generate a magnetic field line movement. Current into the coil produces a magnetic field, the use of magnetic effect of current, so that the electromagnet in the stationary magnets continuously rotating device, electrical energy can be converted into mechanical energy. Principles and by another permanent magnet or magnetic field generated by the coil groups interact generating power DC motor is not moving the stator, the rotor in the direction of the force generated by the interaction of the movement. AC motor is the stator windings through the AC, produce a rotating magnetic field, rotating magnetic field attracts the rotor rotational motion together for the basic structure of a DC motor, including the "armature", "magnetic field", "collector ring", "brush."
Armature: You can rotate around the axis of soft iron multi-turn coil winding. Field magnets: permanent magnets or electromagnets to generate strong magnetic fields. Collector ring: a collector coil for about two to two semicircular termination ring, with the coil rotates, for changing the direction of the current change to the device. Each half turn (180 degrees), the current direction of the coil on the changed once. Brush: usually made of carbon, collector ring brush contact fixing position to be connected to the power supply.

3, the basic structure

Many types of electric motor, to the basic structure, its composition is mainly composed of a stator (Stator) and a rotor (Rotor) is constituted.
The stator is stationary in space, the rotor can be rotated around the shaft, supported by bearings.
Will have a certain air gap between the stator and the rotor, in order to ensure that the rotor can rotate freely.
A coil wound on the stator and the rotor, through the current produces a magnetic field, becomes the electromagnet, one of the stator and the rotor of which is also a permanent magnet.

4, the development history

In 1835, production of the world's first electric vehicle applications can drive small motors for the US a blacksmith Davenport wave (Thomas Davenport). The early 1870s, the world's first to commercialize the invention of the motor by the Belgian electrical engineer Zenobe Theophile Gamme. In 1888, the famous American inventor Nikola Tesla applied Faraday's principle of electromagnetic induction, AC motor invention, namely the induction motor. In 1845, the British physicist Whiston (Wheatstone) linear motor patent application, but the principle was only in the 1960s, attention, and designed a practical linear motor, has been widely used in industry. In 1902, the Swedish engineer Danielson use the concept of the rotating magnetic field induction motor Tesla invented the synchronous motor. 1923, Scotsman James Weir French invention of three-phase variable reluctance (Variable reluctance) stepper motor. 1962, by the aid of the Hall element, the utility of the DC brushless motor has finally come. In the 1980s, the advent of practical beginning of Ultrasonic motor.

5, species classification

The following motor begin to call
Depending on the use of power classification:
Name
Property
DC motors
(DC motor)
Using a permanent magnet or an electromagnet, brushes, commutator and other components, the brush and the commutator to an external DC power supplied, continuously supplied to the rotor coil, and the timely change the direction of the current, so that the rotor can be in the same direction by continuous rotation.
AC motor
(AC motor)
The alternating current through the stator coils of the motor, designed to get around the magnetic field at different times, different locations to promote the rotor, so that continuous operation
* Pulse Motor
Power IC chip through digital processing, a pulse current to control a motor, the stepping motor is a pulse motor.
Constructed according to classification (DC and AC power Jie):
Name
Property
Synchronous motors
(Synchronous motor)
Is characterized by a constant speed and does not require constant speed, starting torque is small, and when the motor reaches operating speed, speed and stability, and high efficiency.
Asynchronous motor
(Induction motor)
Induction motor
Is characterized by simple structure, durable, and can be used to adjust the speed and resistance or capacitance reversing Typical applications are fans, compressors, air conditioners
* Reversible motor
Induction motor is basically the same structure and features, and there is a built-in simple brake mechanism (friction brake) on the rear of the motor, which aims to take the load by adding friction to achieve instantaneous reversible characteristics, and reduce the induction motor due to the action turn over the amount of power generated.
Stepper motor
(Stepping motor)
Characterized by a pulse motor, an angle of rotation of the motor gradually, due to the use of open-loop (Open Loop) controlled manner, and therefore does not require the position feedback device detection and speed detection, we can achieve accurate position and speed control, and good stability.
Servo Motor
(Servo motor)
Characterized by a speed control accuracy and stability, fast acceleration and deceleration response and prompt action (fast reverse, rapid acceleration), a small lightweight, high output power (ie, high power density), high efficiency, widely used in the position and speed control on.
Linear motors
(Linear motor)
The drive has a long stroke and can show high-precision positioning capability.
Other
Rotary converter machine (Rotary Converter), rotary amplifier (Rotating Amplifier), etc.

6, the intended use

A typical induction motor is widely used
Many electric use, ranging from heavy industry, small to small toy has its own trail. Under different conditions can choose different types of motors, the following are some examples: wind system equipment, such as electric fans electric toy cars, boats and other lifts, elevators with power-driven vehicles, such as the Mass Transit Railway, Tram factories and supermarkets electric conveyor belt on a bus
Automatic door electric shutters moving consumer goods
Printer CD-ROM disk drive washer pump electric razor recorder VCR CD turntables industrial and commercial uses fast elevator machine tools (such as: machine) textile machine mixer

7. Additional Information

The basic principle of the electric motor and generator, as were different in the direction of energy conversion, the generator is borrowed by the load (such as hydro, wind) to mechanical energy, kinetic energy into electrical energy, if there is no load, the generator does not have current flow. Electric motors and power electronics, microcontroller has been formed with a new academic discipline known as motor control. Before using the motor must first understand the power they use direct current or alternating current, if it is AC, need to know that it is a three-phase or single-phase alternating current, then the wrong power supply can cause unnecessary losses and danger. After the rotation of the motor if the load is not connected or very light load makes the motor speed quickly, the induced electromotive force is strong, this time the voltage across the motor, power supply voltage minus the induced voltage, so that the current weakened. If the motor load is heavy, slow speed is relatively small induced electromotive force, and thus the power required to provide a large current (power) to correspond to the desired high power output / do work.
Output: refers to the work of the motor per unit time can be carried out, and in accordance with the running speed and the torque of the motor is determined. Rated output: motor at rated voltage, rated frequency can play its best features, a variety of energy and at the same time continuously generated output, such as running speed or torque and other values. Rated output will indicate the value of the usual motor nameplate. Asia usually in watts (W) as a unit, is used in Europe and America horsepower (HP).
Rated power (capacity): The rated output power (watts). Horsepower: one motor horsepower output power units (Horse power, called HP), 1 horsepower (HP) = 746 瓦特 (Watts) Rated voltage: When using the input voltage can be tolerated, use more than the rated voltage, usually motor still running, but its life will be significantly reduced capacitor, even after a long run generate heat and burn. The use of units to V (volts) said. Torque Starting torque: refers to instantly call up when motor torque generated by the motor if a torque greater than the friction restraining load, the motor will not start. Also known as the starting torque. Stop Torque: refers to the maximum torque of the motor at a certain voltage, the output of a certain frequency can once carried the load beyond the scope of this torque, the motor stops immediately. Rated Torque: Refers to produce continuous torque motor rated output at rated voltage and rated frequency. When the operation speed is the rated torque generated. Speed Rated operating speed: Refers to the operating speed of the motor to do the rated output for ideal use of motor trouble-free operation at speed. No annexed running speed: refers to the speed of the motor running under no-load conditions. CW / CCW: refers to the direction of rotation of the motor. CW is clockwise from the output shaft end, while the CCW was running counterclockwise.

8, fault identification

Failure symptoms
Cause
Treatment
The motor can not start, but you can manually operate.
1. centrifugal switch is bad.
2. Start coil shorted or bad connection.
1. Replace the centrifugal switch or use sandpaper its joints.
2. Check pneumatic coil is broken.
Motor does not start, the same can not run after manually.
1. No power.
2. The circuit is broken.
3. Operation coil disconnected.
The shaft is bent.
5. The rotor and stator contact.
1. Check the power supply.
2. Check the circuit.
3. Repair work coil.
4. Adjust or replace the shaft.
5. Replace the bearings.
Speed is slower than normal speed.
1. The power supply voltage is too low.
2. bearing too tight, or the load is too large.
1. Check the power supply voltage is normal.
2. Replace the bearings and reduce burden.
Overheating.
1. overload.
2. coil shorted.
3. coil grounded.
4. operation between the coil and the starting coil shorted.
5. serious bearing wear.
1. To reduce the burden.
2. Check the short circuit coupled to the insulation.
3. The ground isolation.
4. Check the short circuit coupled to the insulation.
5. Replace the bearings.