The effects of excessively high or low oil pressure in the compressor lubricating oil on the compressor’s operation
Thread Content
What is the impact of excessively high or low oil pressure in the compressor lubricating oil on the compressor’s operation?
Too low oil pressure can result in a lack of lubrication in the relevant areas, leading to an increase in temperature of the rotating parts. Dry friction can damage the sliding surfaces, posing a serious threat to the safe operation of the compressor. But what about too high oil pressure? It seems like there shouldn’t be any problem with that, right? Looking forward to the expert's response.
The lubrication and cooling of compressor bearings are achieved through the oil film formed by the lubricating oil within the bearing shells. The oil film can generate a certain centrifugal force to support and lubricate the bearings only under conditions such as specific rotation speed, oil pressure, and bearing clearance. An insufficiently uniform and stable oil film is formed due to low lubricating oil pressure. If it is too high, an oil film cannot be formed quickly.
Only when the rotor speed reaches a certain value can an oil film be established by centrifugal force. If the lubricating oil pressure is too high, a very high rotational speed is required to establish a stable and uniform oil film. But by then, the bearing shells were already in direct friction with the rotor.
If the oil level in the lubricating oil tank is too high, it may prevent smooth oil return, which can lead to significant blockage in the oil return pipe that leads to the space in the bearing box used for venting air. This, in turn, disrupts the slight negative pressure in the bearing box, resulting in oil leakage； At the same time, if the oil level is too high, the oil can overflow the edge of the filter tank and enter the fuel tank without being filtered. When the oil level is too low, the operation of the main oil pump may become unstable. As the oil level drops significantly, the number of oil circulation cycles increases; this reduces the circulation rate and shortens the time the oil stays in the tank, thereby deteriorating the air separation effect