1. The pressure difference between the inside and outside of the reducer: During the operation of the reducer, the frictional heat of the moving pair and the influence of the ambient temperature increase the temperature of the reducer. If there is no ventilation hole or the ventilation hole is blocked, the pressure inside the machine gradually increases The higher the internal temperature, the greater the pressure difference with the outside, and the lubricating oil leaks from the gap under the action of the pressure difference.
2. The structure design of the reducer is unreasonable
1) The inspection hole cover is too thin, and it is easy to deform after tightening the bolt, making the joint surface uneven and leaking oil from the contact gap;
2) During the manufacturing process of the reducer, the castings are not annealed or ageed, and the internal stress is not eliminated, and deformation must occur, resulting in gaps and leakage;
3) There is no oil return groove on the box body, and the lubricating oil accumulates on the shaft seal, end cover, joint surface, etc., and leaks out from the gap under the action of the pressure difference;
4) The design of the shaft seal structure is unreasonable. Early reducers mostly used oil groove and felt ring type shaft seal structure, which caused the felt to be deformed by compression during assembly, and sealed the joint surface gap. If the contact between the journal and the seal is not ideal, due to the extremely poor compensation performance of the felt, the seal will fail in a short time. Although there is an oil return hole in the oil groove, it is extremely easy to block and the oil return function is difficult to play.
3. Excessive amount of oil added: During the operation of the reducer, the oil sump was agitated very badly, and the lubricating oil splashed everywhere in the machine. Cause a leak.
4. Improper maintenance process: When the equipment is overhauled, oil leakage can also be caused due to incomplete removal of dirt on the joint surface, improper selection of sealant, reverse installation of seals, and failure to replace seals in time.