Fractured teeth are a common type of failure in applications. After a tooth fracture occurs, the reducer not only requires high repair costs but also poses significant repair difficulties. Therefore, we need to understand the factors leading to tooth fractures and take preventive measures for this issue. There are many factors contributing to tooth fractures. We will explain them through the following content:
The location of tooth fractures in reducers is usually asymmetrical, and they rarely occur at the tooth root. The fracture surface shape is similar to that of a typical fatigue fracture. On the fracture surface, the fatigue source, smooth or conch-like fatigue crack development zone, and rough instantaneous fracture zone can be clearly observed. The majority are random fractures. This is mainly caused by defects or excessive harmful residual stress. It may be due to inclusions, fine grinding cracks, or improper heat treatment resulting in local fractures. Analyzing from the fracture characteristics and location, the main reasons may be material inclusions, problems with the blank forging; secondly, poor quenching and carburizing processes, or other reasons causing quality issues with the gears themselves.
The centerlines of reducers and motors are on the same axis, so the operation can be stable, especially to enable the gears to reach a good meshing state. If the centerlines of the motor and reducer are not on the same axis, during operation, a large slanting force occurs on the output shaft, causing the gear shaft of the low-speed large gear to tilt, with the centerline not being parallel to the centerlines of the two small gears it meshes with, resulting in a reduction in the meshing surface of the teeth of the low-speed large gear and the two small gears, increasing the load on the teeth. Rotational angles occur at both bearing ends, and the gears are in severe overloading operation for a long time, which is also an important reason for the occurrence of tooth breakage, tooth loss, and other failures.