Summary:...
Although the DC motor is a simple machine, proper and timely maintenance is very important to extend the mission of the motor and equipment. The manufacturers of DC motors in the production department are very aware of the headaches caused by troubleshooting. This article helps you solve several problems that often occur in DC motors.
1. Carbon Brush
The DC motor must be equipped with a suitable load. This is very important for the electrical conductivity of the brushes on the commutator, so the brushes can maintain a specific lubricating capacity when in contact with the commutator under load. When the load of an application is not certain, then the motor already has the wrong brush grade, and the carbon brushes will wear out prematurely, causing carbon dust to accumulate in the motor. This problem will cause irreversible damage to the commutator bar to some extent. Regarding the investigation of carbon brushes, this is very valuable.
Maintain proper, continuous pressure on the brushes to the commutator to deliver the full current density at the proper contact points, in order to reduce premature wear on the carbon brushes. Carbon dust is destructive to insulation and must be maintained by removing dust inside the motor to prevent low megohmmeter readings. A better way to prevent carbon accumulation is to use compressed air to help remove internal dust. A low megohm reading can inform the DC current to shut down the power supply to warn of ground potential.
2. Adjust the brush holder
The frame or yoke part must be properly adjusted to the so-called neutral position. In order to do this, you need to place adjacent carbon brushes around the outside of the commutator and reference the polarity of the armature coil. This is charged by the brushes. Placing the carbon brushes in a neutral position can prevent excessive arcing under load.
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3. Commutator repair
Like carbon brushes, commutators require maintenance from time to time. The strips of the commutator must be repaired in a way to machine the segment commutator. This number of segments is to insulate the strip from the molded mica. Some larger DC motors can be repaired on site to prevent unnecessary extraction of the motor. Maintain a proper maintenance period to ensure that the commutator remains round and the surface does not bounce. If the eccentricity of the commutator is unacceptable, you may end up with a bad carbon brush or carbon brush spring. An out-of-round commutator may lead to potential high rods, which may damage the carbon brushes and cause excessive arcing while the carbon brushes are in contact with the copper rods. A very well-balanced armature is recommended to prevent carbon brushes from causing unnecessary damage to the inverter.
4. Winding problems
Other common DC motor problems are failed magnetic windings or indirect windings. Any winding can have an arc on the carbon brush. The correct data used to replace the failed winding is made in accordance with the manufacturer's correct specifications. When a DC motor is idle and the drive does not have the field weakening option, you may experience heat problems from the field winding. Most medium to large DC motors will have some type of blower system to alleviate this problem.
5. Mechanical DC motor problems
Just like any motor, proper mechanical maintenance is necessary. Bearings must be properly lubricated and repaired, if life is required. Your motor must be assembled in the correct way to alleviate bearing problems, such as misalignment of the terminal housing. Appropriate installation and alignment are some factors that need to be considered so that the motor can ensure operation under peak conditions.
6. Drive maintenance
DC drives may be the culprit of inefficient DC motors. The problem of the silicon-controlled rectifier in the drive can be detected by the commutator. Inside the motor commutator, the carbon brush is close to the nearest ground and metal surface, in the form of an excessive arc. Today's DC drives are programmed with horsepower, voltage, and current under load. This drive may be equipped with a tachometer at the end of the motor shaft, and the motor can enter an overspeed mode through the overvoltage on the armature. This drive hardly responds to the voltage generated by the tachometer. DC is designed to shut down the motor in these cases.
The DC motor itself is a complete motor. Although very complicated. For carbon brushes, carbon brushes, carbon brushes, and the proper maintenance of the commutator, these are all very necessary.
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