Where does NGW122-8 reducer oil leakage usually occur?

NGW122-8 reducer oil leakage usually occurs in the following key parts, mainly caused by seal failure, structural problems or improper maintenance:

‌1. Oil seal part (oil leakage at shaft end)‌

‌Input shaft/output shaft oil seal is aging or worn‌: Long-term operation causes the rubber oil seal to lose elasticity or the lip is worn, resulting in loose sealing.

‌Journal wear or surface roughness‌: Grooves or scratches appear on the contact surface between the shaft and the oil seal, causing the new oil seal to be unable to seal effectively.

‌Improper installation‌: Such as oil seal deflection, dry friction startup or burrs on the shaft, causing initial leakage.

‌2. Oil leakage on the joint surface (box and end cover, box sub-surface, etc.)‌

‌Sealant failure or improper application‌: The glue layer is too thick and easy to crack, and if it is too thin, it cannot fill the gap; assembly without curing can also cause leakage.

‌Deformation of the joint surface or insufficient processing accuracy‌: High-temperature operation or casting stress has not been eliminated, resulting in plane warping and loose sealing.

‌Loose bolts or uneven tightening‌: Insufficient pre-tightening force creates gaps on the joint surface, and lubricating oil seeps out of them.

‌3. The ventilation hole (breathing valve) is blocked‌

When the reducer is running, the temperature rises and the internal pressure increases. If the vent cap is blocked or the valve is too small, the high pressure will "squeeze" the oil out of the weak seal. This is the core reason why many oil leaks occur despite seemingly intact seals.

4. Bearing gland and end cover parts‌

The bearing gland screw is loose, the gasket is damaged, or the oil return groove is clogged, causing lubricating oil to accumulate at the shaft end and then leak.

5‌. The oil level is too high or the lubricating oil is improperly selected‌

If the refueling amount exceeds the upper limit of the oil mark, the oil splash will intensify during operation and increase the pressure at the seal. Oil with too low viscosity will easily seep out from the gap.