Application of Machinable Brush Plating Technology in Repairing Electric Motor Wear
Abstract
The brush-plated repair part outperforms the original one in terms of anti-wear capability. The rotor shaft is usually made of tempered carbon steel or alloy steel. The material of end cover material is cast iron or cast steel. The hardness of tempered carbon steel, alloy steel, cast iron, and cast steel is lower than that of brush plated part. Therefore, the motor rotor shaft or end cover, which is repaired by using the FJY series brush plating technology, has better quality than the original one and it can serve longer in real use.
Keywords: electric motor, motor repair, motor brush plating, rotor repair, rotor brush plating, end cover repair, end cover brush plating, FJY brush plating, bearing position repair, machinable brush plating, cold repair, explosion-proof motor repair, coating thickness detection, FEIST brush plating power supply
heeedfa
The main composition of the electric motor
An electric motor is a device that converts electrical energy into mechanical energy. Its main structure includes two parts: a stator (fixed part) and a rotor (rotating part).
​
Stator: The stationary part of the electric motor is called the stator. Mainly it plays the role of generating a rotating magnetic field or excitation.
​
Rotor: The rotating part of the electric motor is called the rotor. It mainly provides original torque for rotating parts in power machinery.
​
The stator and the rotor are connected by the rotor shaft, bearing, and end cover to form a power assembly (electric motor) that can output rotational power.
​
The form of electric motor wear
In general, there are two typical forms of electric motor wear, including rotor bearing position wear and wear of end cover bearing chamber.
​
Rotor bearing position wear: Normally, there is no relative movement between the rotor shaft and the inner ring of the bearing. It is a static fit between them. However, abnormal conditions such as overheating and poor lubrication can cause wear or strain on the mating surface.
​
Wear of end cover bearing chamber: The electric motor in use will vibrate to different degrees. This causes mechanical wear between the outer ring of the bearing and the bearing chamber.
​
No matter which part of the electric motor is worn, it will affect the output characteristics of the electric motor.
The particularity of electric motor repair
The core of reliable maintenance of rotating machinery is to ensure that its original dynamic balance characteristics are not destroyed. Therefore, all hot repair methods cannot be used. Even with laser cladding, there is a risk of shaft breakage.
​
The cold repair method is the only way to ensure the reliability of motor repair. Brush plating is one of the cold repair methods, but it must solve the problems of coating adhesion and processability after plating.
The application of FJY machinable brush plating technology in electric motor maintenance
The straightness of the rotor shaft directly determines the repair quality of the electric motor. If the brush plating layer is firmly combined with the rotor shaft or bearing chamber to the extent that post-plating cutting can be performed, the brush plating repair quality of the electric motor shaft can be guaranteed to be consistent with the new part.
​
The machinable FJY brush plating technology, which can be used to repair the electric motor, has outstanding features compared with similar technologies:
​
-
The brush plating layer can be machinable. For example, in order to test the bonding force between the brush plating layer and the substrate, a professional motor maintenance unit adopted a method of bottoming out the car to verify the processability of the plating layer. The results show that there is a smooth transition at the interface between the plating layer and the substrate, and there is no peeling, stubble, or peeling phenomenon.
-
The anti-wear performance of the brush-plated repair part is better than the original. The rotor shaft is made of quenched and tempered carbon steel or alloy steel, and the end cover is made of cast iron or cast steel. Their hardness is lower than that of the brush plating layer. Therefore, the motor rotor shaft or end cover, repaired by FJY series brush plating technology, has a longer service life than the original.
-
Brush plated layer can be monitored in real-time if using the FEIST coating thickness monitoring power supply. In this way, performing brush plating just for one time can ensure that the repair size meets the product size tolerance requirements without post-plating processing.
​
​
Application examples
FJY series machinable brush plating technology has been widely used in the repair of rotating equipment such as generators, motors, fans. The service life is longer than the original. Examples (parts) of brush plating repair of motor rotor and end cover are as follows:
Repair of rotor bearing using machinable brush plating
Brush plating repair of motor end cover