If the gear of the reducer is cracked, we must learn the correct method of operation when using it. After all, we must find out the root cause in order to do the corresponding countermeasures in time. Then we will simply analyze Where is the cause of the cracks underneath.

1. Improper gear assembly adjustment
Observe the damaged gear of the reducer, most of the gear teeth have large or small pits at the proximal end on the same side of the force surface, and no pits are found from the middle part of the gear teeth to the other end, indicating that the two gear shafts are being assembled. There is a parallelism error between them, so that the gear teeth are not uniformly stressed across the entire tooth width, and the phenomenon of "one end contact" appears, so there is stress concentration in some areas.

2. Heavy load and large load fluctuations
The reduction box is connected with the melting pump of the extruder, and the function is to pressurize the molten resin. It is a low-speed and heavy-duty reduction box. Since the medium of the melting pump is a variety of resins of different grades, the melting fingers of the resins are quite different, resulting in a large change in the transmission torque of the reducer. In 2003, the extruder was also expanded and transformed, and the production capacity of the whole machine was expanded from 13.3 t/h to 15.5 t/h, but this equipment was not modified. The manufacturer made the equipment at full load or even overloaded operation. The above factors All tend to cause fatigue cracks in the gear.

3. Improper heat treatment of tooth surface

After testing, the hardness of the gear tooth working surface of the reducer is about HRC45, and the hardness of the tooth top surface is HRC53. The hardness of the tooth surface is significantly lower than that of the tooth top. The reason may be due to the greater wear of the tooth surface. For heavy-duty gears, the hardness should usually be above HRC56 to have better wear resistance and fatigue resistance. In comparison, the hardness of this gear is obviously low, and it is prone to pitting corrosion in the stress concentration part.

If there is a crack in the reducer, we must find the corresponding cause in time, so that we can make a timely response plan and better improve the efficiency of the equipment.