Dry 丨 wind turbine gearbox lubricant foam causes

Lubricant foam generated during the use of lubricants will not only occur in the air resistance and flow breakage phenomenon, but also lead to fatigue wear and lubricant consumption, therefore, the lubricant is required to have good anti-foaming properties. Briefly analyze the reasons for the formation of lubricating oil foam and harm, and summarize the common physical and chemical methods to reduce foam and its mechanism, citing the addition of anti-foaming additives and pre-heating of the lubricant to control the foam content of the case.

 

Foam formation causes ---- lubricant itself or equipment-related reasons

 

The lubricant is in contact with the air in the environment, and the air will naturally dissolve into the oil. How much air can be dissolved in the lubricant depends on the temperature, pressure, and the solubility of the lubricant itself to air. At atmospheric pressure, air typically makes up 9% of its volume in mineral oil. As the pressure increases, the amount of air dissolved in the lubricant increases; as the pressure decreases, some of the air separates from the lubricant and a new dissolution equilibrium is reached. The separated air is surrounded by an oil film forming bubbles. In addition, the air separation in the lubricant is also affected by temperature changes.

 

Unqualified anti-foaming properties of new oils, failure of anti-foaming agents during storage, or filtering out of anti-foaming agents by the cartridge can lead to excessive foaming of the oil after use. The aging and deterioration of lubricating oil in the process of use, resulting in a decrease in the surface tension of the oil, will also lead to foam. Lubricating oil contains a variety of different properties of the additives, most of these additives are polar compounds, with surface-active effect, prompting the oil to produce foam.

 

Gearboxes in operation will generally be part of the air involved in the lubricant, the formation of air bubbles. Common causes:

1)Leaks in the suction pipe, oil pump valve parts and seals, etc. lead to the inhalation of air;

2)The return pipe is not properly positioned, the oil flow is turbulent churning occurs, and air is involved;

3) Gear box is polluted, such as water, other oils, liquids, chemicals and impurities;

4)Air in the pipeline or air mixed in the tank;

5) low oil temperature, viscosity, pumping oil supply system air resistance.