Special Reducer for Belt Conveying

Causes of Shaft Breakage of Special Reducer for Belt Conveying:

Most coal mine transportation equipment has the characteristics of large transportation capacity, complex working environment, strong bearing capacity and long transportation distance. The belt conveyor reducer is a very important part in coal mine production. For the shaft breakage problem, it is necessary to understand the causes and corresponding measures.

1) General Causes

At the high-speed shaft end of most reducers arranged with vertical shafts, there will be phenomena of successive shaft breakage or successive shaft breakage of several reducers on the same belt conveyor. The fracture surface of the shaft breakage is generally neat, and the section is generally perpendicular to the length direction of the shaft. This situation generally occurs underground.

2) External Factors

The external factors causing shaft breakage can generally be summarized into four points:

① The fixing degree of the reducer itself leads to the breakage of the high-speed shaft;

② The bearing capacity of the selected reducer is insufficient;

③ The dynamic balance of the brake wheel and coupling is poor;

④ The deviation of installation concentricity is too large.

Selecting the wrong reducer gear during operation will lead to shaft breakage. This is because whether the actual service power of the reducer exceeds or is lower than the rated power of the reducer, it belongs to the scope of abnormal use. If the reducer works in an abnormal state for a long time, it will cause the breakage of the high-speed shaft of the driving reducer and reduce the safety factor of the reducer.

3) Internal Factors

The internal factors causing shaft breakage can also be summarized into four points:

① Excessive stress at the shaft fracture during the design of the reducer;

② The transition fillet at the shoulder of the high-speed shaft of the reducer is small;

③ The heat treatment quality of the high-speed shaft is unqualified, and the hardness distribution is uneven;

④ Improper selection of materials for the high-speed shaft.

In general, it is the unreasonable design and problems of the high-speed shaft that lead to shaft breakage. The unreasonable design is more reflected in that the combined bending and torsion stress of the rotating shaft exceeds the safe stress range designed by the shaft itself; the problems of the high-speed shaft are reflected in the material selection.

The working intensity of the belt conveyor reducer for coal mines is very high. It is necessary to select strong and thermally conductive materials as the materials for the high-speed shaft which operates at high speed and has high friction. Any negligence in material selection and operation will cause the shaft breakage of the reducer.

All potential safety hazards arising in the process of mine production cannot be ignored. Only by implementing all aspects such as design, manufacturing, installation and use in place can the occurrence of shaft breakage be fundamentally reduced.