Due to improper disassembly and assembly techniques during maintenance, the teeth became bent. After reinstallation, the teeth were skewed, causing uneven circumferential force on the gear coupling and resulting in equipment vibration. Excessive weight deviation after assembly disrupted the dynamic balance of the shaft system, leading to equipment vibration. Common and obvious defects such as cracks and deformations in the coupling flange, as well as excessive or insufficient clearance between the coupling bore and the shaft journal, are relatively easy to detect and handle.

The tooth surface of the spline coupling undergoes gas nitriding treatment. Torque is transmitted through the tooth engagement, enhancing the torque transmission without affecting the toughness of other parts. The gas nitriding treatment is carried out on the tooth surface area, while other areas are coated with anti-seepage agents for anti-seepage protection. Surface blemishes with slightly darker color and dim metallic luster appear on the inner and outer teeth areas of the spline coupling. The direct cause is that the nitrogen concentration in this area is different from that in the normal area.

 The tooth-type coupling is a type of coupling that achieves the connection of two halves of the coupling through the meshing of internal and external teeth. It is suitable for horizontal transmission shafts that operate under heavy loads or at high speeds. The damage forms of the tooth-type coupling are generally tooth wear and tooth breakage. The tooth-type coupling achieves this by lubrication, creating an oil film between the contacting tooth surfaces, preventing direct hard wear of the tooth surfaces and thus reducing the rapid wear of the tooth surfaces.

The tooth-type coupling is a type of coupling that achieves the connection of two halves of the coupling through the meshing of internal and external teeth. It is suitable for heavy-load operation or high-speed rotation of horizontal transmission shafts. The forms of damage to the tooth-type coupling are generally tooth wear and tooth breakage. The tooth-type coupling is commonly lubricated by applying lubricating grease between the contacting tooth surfaces. This is a common lubrication method for the tooth-type coupling. Due to the lubrication of gear transmission and rolling bearings, the lubricating oil or grease in the gearbox or bearing space must not be filled to the brim; there should be some space left. Generally, it is required that the space for adding lubricating grease should be about two-thirds of the total. This is to prevent the heating during the operation of gear transmission and rolling bearings, which could cause the equipment to burn out.