How to ensure the moisture-proof and dust-proof performance of mining motors?

1. Measures to ensure moisture-proof performance
(I) Structural sealing
1. Shaft seal protection
Use high-quality seals, such as double-lip oil seals or labyrinth seals, on the shaft extension of mining motors. Double-lip oil seals have two sealing lips, which can effectively prevent external moisture from entering the motor along the shaft. Labyrinth seals increase the resistance to moisture entry through tortuous sealing channels.
Check the wear of the shaft seal regularly. When the sealing lip is worn or the sealing effect is reduced, replace the shaft seal in time. At the same time, when installing the shaft seal, ensure that it is installed correctly to avoid poor sealing due to improper installation.
2. End cover seal
The end cover of the motor is sealed with a sealing gasket or sealant. The sealing gasket should be made of oil-resistant and aging-resistant materials, such as rubber asbestos gaskets or fluororubber gaskets. When assembling the end cover, ensure that the sealing gasket is placed correctly without damage or wrinkles.
In the case of using sealant, the sealant should be evenly applied, and the end cover should be assembled before the sealant solidifies to ensure the sealing effect. The bolts of the end cover should be tightened to the specified torque to prevent loose sealing due to loose bolts.
(II) Insulation moisture-proof treatment
1. Selection of insulating materials
Insulating materials with good moisture-proof properties should be selected. For example, polyesterimide enameled wire or polyimide enameled wire can be used for the insulation of the motor windings. These insulating materials have high moisture resistance and insulation strength.
In the manufacturing process of the insulating material, moisture-proof agents are added or moisture-proof treatment is performed. For example, moisture-proof paint is impregnated to form a moisture-proof protective film on the surface of the insulating material to prevent moisture from invading the interior of the insulating layer.
2. Drying treatment
During the manufacturing and maintenance of the motor, drying treatment is performed. During manufacturing, after the winding is impregnated with insulating paint, it is dried to fully solidify the insulating paint and improve moisture-proof performance. During maintenance, if the motor is damp, a drying oven can be used for drying. The drying temperature and time should be determined according to the specifications and moisture level of the motor. The general drying temperature is around 100-150°C, and the drying time may take several hours to dozens of hours.
(III) Environmental control
1. Drainage and ventilation
In the installation environment of the mine, ensure that there is a good drainage system around the motor installation location to prevent the motor from being soaked by water. For example, set up drainage ditches or use drainage pumps at the underground motor installation location to remove water in time.
The ventilation system should be reasonably designed to maintain air circulation and reduce environmental humidity. Ventilation can take away moisture around the motor and prevent moisture from condensing on the surface of the motor. However, attention should be paid to the moisture-proof treatment of the vents to prevent external humid air from blowing directly to the motor.
2. Humidity monitoring
Install a humidity sensor in the working environment of the motor to monitor the environmental humidity in real time. When the humidity exceeds the set value, take corresponding measures, such as strengthening ventilation and using dehumidification equipment. For important mining motors, the humidity monitoring data can be transmitted to the monitoring center for remote monitoring.
II. Dust-proof performance guarantee measures
(I) Dust-proof vents
1. High-efficiency filter device
Install a high-efficiency dust-proof filter device, such as an air filter or filter, at the vent of the motor. The air filter can adopt a multi-layer filtering structure, including a coarse filter layer, a fine filter layer and an activated carbon adsorption layer. The coarse filter layer is used to filter larger dust particles, the fine filter layer further filters fine dust, and the activated carbon adsorption layer can absorb harmful gases and odors in the air.
The filter can be a metal filter or a fiber filter. The metal filter has high strength and can be washed and reused. The fiber filter has good filtering effect but needs to be replaced regularly. According to the characteristics of mine dust and the ventilation requirements of the motor, select a suitable filter device and clean or replace the filter element regularly to ensure ventilation and dust prevention effects.
2. Ventilation port design
Optimize the design of the motor vents, reduce the area and number of vents, and reduce the possibility of dust entering. The shape of the vents can be a zigzag or inclined design to prevent dust from entering directly. At the same time, a guide plate is set around the vents to guide the airflow direction and prevent dust from accumulating near the vents.
(II) Casing dust prevention design
1. Overall sealing
Try to minimize the gaps and holes in the motor casing and adopt an overall sealing structure. For the necessary openings on the shell, such as the opening of the junction box and the observation window, they should be sealed. The junction box can be a sealed junction box, and the box cover and the box body are sealed with a rubber sealing ring, and the terminal should be sealed to prevent dust from entering through the gap between the terminal.
The observation window uses sealed glass, and the glass and the shell are sealed with sealant. In the manufacturing process of the motor, the processing accuracy of the shell must be strictly controlled to ensure that the connection between the various parts of the shell is tight and there is no leakage point.
2. Shell surface treatment
The surface of the motor shell is specially treated to make it less likely to absorb dust. For example, the dust-proof paint can be sprayed. The dust-proof paint can make the surface of the shell smooth and reduce the adhesion of dust. At the same time, the color selection of the shell can also consider dust prevention factors, such as choosing a light-colored shell. The light-colored shell is relatively difficult to be found to have dust adhesion in the mining environment, which is convenient for timely cleaning.
(III) Regular cleaning
1. Cleaning system
Establish a regular cleaning system to regularly clean mining motors. The cleaning cycle is determined according to the severity of the mine dust, and generally it can be cleaned once a week or every two weeks. When cleaning, first use compressed air to blow away the dust on the surface of the motor, then wipe it with a damp cloth. For dirt that is difficult to remove, you can use a special cleaning agent.
During the cleaning process, be careful to avoid moisture entering the inside of the motor, especially for parts such as vents and junction boxes, and be careful. At the same time, clean the environment around the motor to reduce the dust source in the surrounding environment.
2. Internal cleaning (careful operation)
If dust is found inside the motor, internal cleaning is required. Before performing internal cleaning, cut off the power supply and wait for the motor to cool completely. Then open the end cover of the motor and carefully remove the internal dust with clean compressed air or vacuum equipment. When cleaning the inside, avoid damaging the windings and other parts of the motor. After cleaning, reassemble the motor in accordance with regulations and ensure good sealing.