











Most motors, whether AC motors or DC motors, will fail due to time, which may not be electrical in nature. Since there are few moving parts, motors without brushes and commutators (such as AC (alternating current) induction motors) have the longest service life. AC and DC brush motors (such as those used in vacuum cleaners and power tools) generate high power in a short period of time and stop working when worn brushes and commutators are issued. To check any type of faulty motor, follow logical steps.
If you want to learn more, you can read the comprehensive guide below.
This passage is going to talk about the followings of electric motor:
(1)Check bearings and shafts of an electric motor
(2)Check the electric motor windings with a multimeter
(3)Ensure that the electric motor fan is in good condition and firm
Motor bearings are one of the most vulnerable components. Bearings are subject to regular wear and tear, so you need to replace them over time. You must check the bearings regularly, because if you continue to use the motor with worn bearings, it will damage the mechanism and reduce the efficiency of the motor.
The bearings are easy to check. All you need to do is rotate the bearings to make sure they rotate smoothly and freely. Another way to check the bearing is by pushing and pulling the shaft to which the bearing is connected. The bearing should rotate smoothly and the shaft should be able to move smoothly. That is, if you hear scratching or feel any friction, you may need to replace the bearing. If the friction is small, the bearing may only need lubrication.
Not surprisingly, the windings of a motor are critical to its machinery. You should check the wear of the winding regularly, but more importantly, you need to analyze its resistance. First, you will need a multimeter to test the windings. First, set the multimeter to read ohms, and then test the wires and terminals of the motor. You should test the "short to ground" in the winding circuit and open the winding or shorts.
To test whether the motor is shorted to ground, you need to set the multimeter to ohms and disconnect the power to the motor. Then check each wire, looking for infinite readings. Or, if the reading is 0, it may be a cable problem. To determine whether the cables are damaged, each cable should be tested separately and make sure that no wires are touching. Testing separately allows you to find the cable causing the problem. On the other hand, if each cable provides unlimited readings, it may be a motor problem, so you should hire a professional repair service.
Too many people forget to check and maintain the fan of the electric motor. The fan is very important to the performance of the motor, because it keeps the motor cool and can run for a long time. You might suspect that the fan is easily clogged with dust and debris, which reduces airflow and keeps heat in. Although the outside of the fan looks relatively clean, dust and debris may accumulate elsewhere, which can slow the fan. When removing the fan cover for cleaning, also test the fan and make sure it spins freely. In addition, the fan should be fixed on the motor. Otherwise, the fan will not operate normally, and the motor will overheat, and eventually it will definitely be damaged.
What is a refrigerator motor - standard motor
According to the production practice of our factory, we will make some introductions to the research on the design, manufacturing process and reliability of refrigerator motor. Square and a variety of trough shapes, as shown in Figure 1. This kind of stator punching is more complicated in manufacturing than the circular punching of the standard series motor. But today the processing equipment is advanced, the die life is continuously improved, and it is still economical to analyze from the economic point of view in mass production.
What is the refrigerator motor - special requirements for the refrigerator motor
In order to reduce the noise and the volume, the refrigerator motor and the compressor are installed in the same closed casing. And it is operated in a mixed gas of Freon and refrigeration oil having a certain pressure and temperature, which is a heavy-duty starting. The motor torque is proportional to the square of the feed voltage. When the grid voltage fluctuation is large, the torque varies greatly. When the refrigerator is running, the ambient temperature of the refrigerator changes greatly, and the motor load of the refrigerator changes greatly. The motor must have a large overload capacity and starting torque to operate reliably. The maximum torque and starting torque of the refrigerator motor are much higher than that of the standard series motor. The ratio of the maximum torque to the rated torque is generally more than 2.5 times, and the ratio of the starting torque to the rated torque is generally more than twice.
Have you ever considered how to control robotic vehicles with bomb retention devices that are usually used for military purposes, or how metal cutting and shaping machines provide precise motion for metal processing milling, lathes and bending, or how antenna positioning systems can control azimuth and altitude?
Servo motor applications are most commonly used in closed-loop systems. In closed-loop systems, precise position control is usually used in industrial and commercial applications. How does a servo motor work?
This passage is going to talk about the followings of servo motor:
(1) Basic knowledge of servo motor
(2) How to control servo motor?
(3) Application of servo motor
Let's start with the basics of servo motors. The servo motor is a part of the closed loop system and consists of several parts, namely the control circuit, the servo motor, the shaft, the potentiometer, the drive gear, the amplifier and the encoder or resolver.
Servo motor is an independent electrical device that can rotate machine parts efficiently and accurately. The output shaft of the motor can be moved to a specific angle, position and speed that conventional motors do not have. Servo motors use conventional motors and couple them with sensors to provide position feedback.
The controller is the most important part of the servo motor specially designed and used for this purpose. Servo motor is a closed-loop mechanism that incorporates position feedback to control rotational or linear speed and position. The motor is controlled by an analog or digital electrical signal, which determines the amount of movement that represents the final command position of the shaft. An encoder is used as a sensor that provides speed and position feedback. The circuit is built into the motor housing which is usually equipped with a gear system.
The servo motor is controlled by sending electric pulses of variable width or pulse width modulation (PWM) through the control line. There are minimum pulse, maximum pulse and repetition rate. Servo motors usually can only rotate 90° in either direction to achieve a total of 180° movement. The neutral position of the motor is defined as the position where the servo motor system has the same potential rotation in the clockwise or counterclockwise direction. The PWM sent to the motor determines the position of the shaft based on the duration of the pulse sent through the control line; the rotor will turn to the desired position. The servo motor expects to see a pulse every 20 milliseconds (ms), and the length of the pulse will determine how far the motor rotates. For example, a 1.5ms pulse will turn the motor to the 90° position. Shorter than 1.5 milliseconds will move it counterclockwise to the 0° position, longer than 1.5 milliseconds will move the servo motor clockwise to the 180° position.
The variable pulse width of the servo motor controls the servo motor position. When these servers are commanded to move, they will move to and maintain that position. If an external force presses on the server while the server maintains its position, the server will prevent it from moving out of that position. The maximum force the server can apply is called the torque level of the server. Servo motors does not maintain its position forever; the position pulse must be repeated to instruct the servo motor to stay in place.
The application of servo motors has been applied to many industrial and commercial systems and products, such as robotics, where servo motors are used at each "joint" of the robot to perform its precise angle of motion.
Camera auto focus uses a servo motor built into the camera to accurately correct the position of the lens to sharpen out-of-focus images.
In antenna positioning systems, servo motors are used to locate the azimuth and elevation angles of antennas and telescopes, such as the positioning system used by the National Radio Astronomy Observatory in the United States.
At this point, the article is over, about what is a servo motor and its working principle. I hope this helps you understand the conditions required to create your own motion control project.
An AC motor is an electric motor driven by an alternating current (AC). The AC motor commonly consists of two basic parts, an outside stator having coils supplied with alternating current to produce a rotating magnetic field, and an inside rotor attached to the output shaft producing a second rotating magnetic field. The rotor magnetic field may be produced by permanent magnets, reluctance saliency, or DC or AC electrical windings.
Less common, AC linear motors operate on similar principles as rotating motors but have their stationary and moving parts arranged in a straight line configuration, producing linear motion instead of rotation.
Operating Principles
The two main types of AC motors are induction motors and synchronous motors. The induction motor (or asynchronous motor) always relies on a small difference in speed between the stator rotating magnetic field and the rotor shaft speed called slip to induce rotor current in the rotor AC winding. As a result, the induction motor cannot produce torque near synchronous speed where induction (or slip) is irrelevant or ceases to exist. In contrast, an independently excited rotor winding. The synchronous motor produces its rated torque at exactly synchronous speed. The brushless wound-rotor doubly fed synchronous motor system has an independently excited rotor winding that does not rely on the principles of slip-induction of current. The brushless wound-rotor doubly fed motor is a synchronous motor that can function exactly at the supply frequency or sub to super multiple of the supply frequency.
Other types of motors include eddy current motors, and AC and DC mechanically commutated machines in which speed is dependent on voltage and winding connection.