1. The pressure difference inside and outside the reducer: During the operation of the reducer, the friction and heating of the moving pair and the influence of the ambient temperature increase the temperature of the reducer.If there are no vents or the vents are blocked, the pressure in the reducer will gradually build up.The higher the temperature in the reducer, the greater the pressure difference with the outside, and the lubricating oil will leak out from the gap under the action of the pressure difference. 2. Unreasonable reducer structure design 1) The inspection hole cover is too thin, and it is easy to deform after tightening the bolts, resulting in uneven joint surface and oil leakage in the contact gap; 2) During the manufacturing process of the reducer, the casting will not be annealed or aged, and the internal stress will not be eliminated, so it must be deformed and create a gap, resulting in 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 from the gap under the action of differential pressure; 4) The structural design of the shaft seal is unreasonable.Early reducers mainly used oil grooves and felt ring shaft seal structures.During assembly, the felt is compressed and deformed, and gaps on the joint surfaces are sealed.If the contact between the journal and the seal circle is not ideal, the seal will fail in a short time due to the poor compensation properties of the felt.Although there is an oil return hole in the oil groove, it is easy to block and difficult to play the oil change function. 3. Excessive oil filling: During the operation of the reducer, the stirring oil pool is severely stirred, and the lubricating oil splashes in the reducer.If the oil is filled too much, a large amount of lubricating oil will accumulate in the shaft seal, joint surface, etc., causing leakage. 4. Improper maintenance process: During equipment maintenance, due to incomplete removal of dirt on the joint surface, improper selection of sealants, seals, reverse installation of seals, oil leakage will also cause oil leakage.
