Oil leakage from the pump bearing cover
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The pump’s rear bearing cover is equipped with a labyrinth seal; oil leakage occurs after the machine is started, at about 10 drops per minute, while no leakage takes place when the machine is shut down. What is the cause of oil leakage from this labyrinth-type sealing gland? Why does it stop leaking after it stops running?
Excessive lubricant, caused by thermal expansion.
First, check whether too much oil has been added. Then examine whether the leakage is caused by a blocked breather cap in the bearing housing. Also check if the compensating oil reservoir is filling the system abnormally; it’s also possible that sludge accumulated over time has blocked the oil return passage, resulting in leakage. If it has just been overhauled, could it be that negligence led to the oil return hole not being directed downward?
I don’t have much contact with this, so I’ll also learn *it
In pumps equipped with labyrinth-type oil seals, oil leakage is mainly caused by an excessive amount of lubricating oil. An excess of lubricating oil occurs because the oil reservoir keeps feeding oil into the pump. In such cases, it is necessary to check whether the air vent of the pump is blocked and whether the oil reservoir is positioned correctly. If oil leakage persists even when the oil level indicated by the sight glass is not low, then it is necessary to check whether the return port of the labyrinth seal is installed properly and whether the return hole is blocked.
If too much oil is added, oil leakage should occur even when the machine is shut down; moreover, oil leakage will stop once the level of lubricant falls below the top of the gland. Many reasons for oil leakage have been mentioned above; if it has just been overhauled, the oil leakage may be caused by the return oil hole of the bearing cover not being oriented downward ； If the oil leakage occurs suddenly, it may be due to a blocked return oil hole or excessive wear in the oil seal, which causes the leakage
This post was last edited by TransientBeauty on July 1, 2016, at 09:56. I guess too much oil was added
This situation cannot be caused by an excess amount of oil (if that were the case, it would have been resolved already, so there would be no need to ask questions). It can be assumed with high certainty that the issue is due to an improper installation position of the compensating oil reservoir; reducing the oil level in this reservoir will solve the problem. One way to do this is by adding a \"Z\"-shaped tube before the interface of the compensating oil level gauge. This issue is actually a quality problem in pump manufacturing – the screw hole for the oil cup on the bearing housing is located too high.
For the labyrinth seal of the bearing cover, check whether there is an oil return groove at the bottom of the labyrinth channel; if none exists or it is too shallow, this will result in poor oil return and oil leakage
It’s likely that the level of lubricant exceeds the value specified by the oil gauge.