A pressure difference between the inside and outside of the reducer.
During the operation of the reducer, the friction and heat of the moving pair and the influence of the ambient temperature will cause the temperature of the reducer to rise. If there are no ventilation holes or the ventilation holes are blocked, the pressure inside the machine will gradually increase. The higher the temperature inside the machine, the greater the pressure with the outside world. The greater the difference, the lubricating oil will leak out from the gaps under the action of the pressure difference.
The structural design of the reducer is unreasonable.
1) The inspection hole cover is too thin, and it is easy to deform after tightening the bolts, making the joint surface uneven and causing oil leakage from the contact gap;
2) During the manufacturing process of the reducer, if the casting is not annealed or aged, and the internal stress is not eliminated, deformation will inevitably occur, creating gaps, leading to leakage;
3) There is no oil return groove on the box, and lubricating oil accumulates in the shaft seal, end cover, joint surface, etc., and leaks out from the gaps under the action of pressure difference;
4) The shaft seal structure design is unreasonable. Early reducers mostly used oil groove and felt ring type shaft seal structures. During assembly, the felt was compressed and deformed, and the gap between the joint surfaces was sealed. If the contact between the journal and the seal is not ideal, the seal will fail in a short time due to the extremely poor compensation performance of the felt. Although there is an oil return hole on the oil groove, it is easily blocked and the oil return function is difficult to exert.
Improper maintenance process.
During equipment maintenance, oil leakage may also occur due to incomplete removal of dirt on the joint surface, improper selection of sealant, reverse installation of seals, failure to replace seals in time, etc.
Too much oil.
During the operation of the reducer, the oil pool is stirred very much, and the lubricating oil splashes everywhere in the machine. If the amount of oil is too much, a large amount of lubricating oil will accumulate in the shaft seal, joint surface, etc., causing leakage.
