Lubricant-Protector of Industrial Equipment

Lubricant-Protector of Industrial Equipment

Reducing friction is one of the main purposes of lubricating oil. In addition, lubricating oil has other functions. For example, the lubricating oil film can prevent rust; prevent metal from being corroded; the lubricating oil can also play a cleaning role. The impurities inside the equipment are like Like the toxins in our bodies, they are removed from the oil through the filter element; the cooling effect, friction between metals generates heat, and the lubricating oil flows through the metal surface to take away the heat.

　　Lubrication is a frequently encountered problem in equipment maintenance, but what exactly is lubrication? Speaking of lubrication, the scene in our minds may just apply oil or grease to the mechanical friction surface to reduce friction. Although this concept is correct, it is only one aspect of lubrication.

Many substances can be used for lubrication, the most common are lubricating oil (liquid oil) and grease (usually paste at room temperature). Grease and lubricating oil are thicker because the grease is used on the basis of lubricating oil. Thickener. The oil used for lubrication can be mineral oil derived from petroleum, or artificial chemically synthesized oil, and vegetable oil and animal oil can also be used as lubricating oil. The lubricating oil and grease used today are mainly derived from petroleum or synthetic oil. The oil before adding additives and thickening agents is called base oil and is the main component of lubricating oil. The base oil itself has lubricity, but in order to optimize the overall performance of the base oil, we added some additives. Mineral oil can meet common industrial lubrication requirements. Therefore, more than 90% of current oil products are based on mineral oil. Synthetic oil has better performance. The use of vegetable oil is mainly for environmental protection.

　　Additives can optimize the performance of base oils, suppress bad properties, enhance beneficial properties, and even give base oils some new properties. However, the more additives are not the better, because additives are chemical substances, and various additives must be properly matched in categories and proportions to achieve the desired effect. In addition, the number of additives should also be considered in the application. For example, the lubricating oil (oil) of a car engine needs to have a better cleaning and dispersing effect to remove carbon deposits and soot in the engine. The lubricating oil used by heavy-duty machinery may be added Extreme pressure additives to increase wear resistance.

　　The role of lubrication:

　　 Reduce friction is one of the main purposes of lubricating oil, but in addition to reducing wear, lubricating oil has other functions, such as lubricating oil film can prevent rust and prevent metal corrosion. Lubricating oil can also play a cleaning role, and the impurities inside the equipment are like toxins in our body, which are removed from the oil by the filter. Cooling effect: friction between metals generates heat, and the lubricating oil flows through the metal surface to take away the heat.

　　 Three states of lubrication:

　　 There are three types of lubrication: full-film lubrication, boundary lubrication, and mixed lubrication. They are in three different states, but they all rely on lubricating oil to lubricate and resist wear.

　　Full-film lubrication:

　　 Full film lubrication is divided into two types-hydrodynamic lubrication and elastohydrodynamic lubrication. Hydrodynamic lubrication refers to two sliding friction surfaces that move relative to each other. The two friction surfaces are completely separated by a fluid lubricating film produced by the relative speed to avoid direct contact between them and dry friction and wear. Elastohydrodynamic lubrication is similar to hydrodynamic lubrication. It also relies on a layer of fluid lubrication film to separate the contact surfaces. The difference is that the relative motion between the contact surfaces is rolling, and the formed full-film lubrication film bears greater pressure than hydrodynamics For lubrication, the resulting lubrication separation film is thinner than that under hydrodynamic lubrication.

Even the metal with high processing precision, the surface is not pure and smooth. Under the microscope, we can see that the metal surface is actually pitted. The burrs are the protrusions that we can already find with the naked eye, and the higher metals under the microscope The raised parts are peaks that are difficult to see with the naked eye, but they are important for lubrication. In order to achieve full-film lubrication, the thickness of the lubricating film must exceed the height of these peaks and separate them completely to avoid peak-point contact between the two contact surfaces. It can achieve full-film lubrication, which is the best lubrication state, and can achieve the most effective protection for the mechanical contact surface.

　　Boundary lubrication:

Although full-film lubrication is ideal, there are some situations where a complete lubrication film may not be formed, such as frequent start and stop of the machine, impact load, speed, and load factors that are not sufficient to form full-film lubrication. These conditions will cause boundary lubrication. . It is good to be able to form a complete lubricating film, but when the conditions are insufficient, a complete lubricating film cannot be formed, or the lubricating film becomes thinner (at high temperatures), the transition from liquid friction to dry friction (direct contact between friction surfaces) occurs before the critical process. State is boundary lubrication. Therefore, in combination with the structure and use of the machine, some equipment requires the use of extreme pressure lubricants, which contain extreme-pressure additives (EP: extreme-pressure additives), or anti-wear additives (AW: anti-wear additives). Realize full-film lubrication. When boundary lubrication occurs, these additives play a role in protecting the mechanical surface. This type of additive can be adsorbed on the metal surface to form a protective layer to avoid metal wear. When boundary lubrication occurs, extreme pressure additives are used to protect the metal surface. Compared with full-film lubrication, boundary lubrication produces more lubricating film friction and generates more heat, but it avoids complete dry friction.

　　Mixed lubrication:

　　The state of mixed lubrication refers to the situation where full film lubrication and boundary lubrication are mixed. As we mentioned earlier, if the peak point of the metal surface is higher than the lubricating oil film, it will contact each other. In mixed lubrication, although most areas are in full-film lubrication, when these peaks are in contact, local boundary lubrication will occur.