The common conveying medium of coal mining scraper conveyor is powdery material. The coal mining scraper conveyor not only ensures the continuous and stable material transportation, but also the transportation speed meets the corresponding requirements, and the material will not overflow or be scattered during the transportation process.
In view of the above requirements, and on the basis of fully considering the characteristics of the powder material, the sealing performance of the coal mining scraper conveyor is an important issue: if the shaft and bearing box of the coal mining scraper conveyor are not well sealed, fine powder is usually smooth. The shaft leaks out and enters the bearing housing, causing damage to the bearing, resulting in frequent maintenance and affecting the stable operation of the equipment. Therefore, trying to solve the bearing sealing problem of the coal mining scraper conveyor is the key to reducing the maintenance workload and improving the stable operation efficiency of the coal mining scraper conveyor.
The coal mining scraper conveyor is composed of a spiral shaft with spiral blades, a barrel and a bearing device. Considering the importance of hermeticity, the seal between the screw shaft and the bearing is double oil seal. The oil seal prevents fine powder from entering the bearing housing, and the seal on the right prevents the grease from the bearing from flowing into the cylinder. The oil seal is also called a rotary lip seal. In the free state, the inner diameter of the oil seal is smaller than the diameter of the shaft, that is, a certain amount of interference. After packing the oil on the shaft, the pressure of the cutting edge and the contraction force of the self-tightening spring exert a certain radial holding force on the sealing shaft and block the leakage gap to achieve the purpose of sealing.
The higher the rotation speed of the rotary shaft of the coal mining scraper conveyor, the greater the friction of the oil seal on the shaft, the higher the temperature rise and the lower the life of the oil seal. The design point of the oil seal seat is to ensure the coaxiality between the oil seal seat hole and the rotating shaft. Ensure the interference of the oil seal lip on the rotating shaft. However, in actual operation, due to oil seal failure, bearing damage caused by the oil seal in the oil seal is still very common.
