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Egmec Industry Co., Ltd.
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Lubrication Equipment
Friction in the full-film lubrication state, which is an ideal situation, however, how to create conditions and take measures to form and meet the state of the full-film lubrication is more complex, long-term production to exploration and research practice, continuous lubrication principle, while others are more mature, and some are studying. Common to the hydrodynamic lubrication, hydrostatic lubrication Hydrodynamic lubrication, boundary lubrication, extreme pressure lubrication, solid lubrication, lubrication of lubrication theory, make a brief introduction.
1. The hydrodynamic lubrication:
Into the friction surface by the rotation of the bearing Vice journal lubricating oil, hydraulic fluid dynamic action of the wedge-shaped gap formation of the lubricating oil viscosity and oil bearing Vice, namely the formation of the bearing oil film, called hydrodynamic lubrication. Assumptions of hydrodynamic lubrication theory is the viscosity of the lubricant, the viscosity of the lubricating oil at a certain temperature does not vary with changes in pressure and change; followed by the assumption that students relative friction movement of the surface is rigid, ie by upload and film pressure, without regard to its elastic deformation. Under the above assumptions, the general non-overloaded (sliding bearing contact pressure of 15MPa), this assumption is close to the actual situation. However, in the rolling bearing and gear surfaces contact pressure increased to 400 ~ 1500MPa, the above assumptions with the actual situation. Then the deformation up to the film thickness of the friction surface several times, and the elastic deformation of the metal friction surface lubrication and lubricants viscosity change with pressure of these two factors, to study and calculate the pattern and thickness of the film formation, film cross-section shape and The pressure distribution within the film more with the actual lubrication on called elastic hydrodynamic lubrication.
2. Static pressure lubrication:
By a high-pressure hydraulic oil supply system will have a certain pressure of lubricating oil to the holidays flow damper, forced for the gap of the friction surface of the deputy campaign (such as hydrostatic slide bearing clearance, the plane hydrostatic slide guide the gap, the gap medium static pressure screw). Not yet started the movement, the friction surface by high-pressure oil separated, forced to form a film, thus ensuring the deputy campaign can withstand a certain load conditions, completely in the state of the liquid lubrication, the lubrication is called hydrostatic lubrication.
3. Dynamic, static pressure lubrication:
With the development of science and technology in recent years in industrial production, a new type of dynamic and static pressure lubricated bearing. Hydrodynamic, hydrostatic joint bearings give full play to the advantages of hydrodynamic bearings and hydrostatic bearings of both, to overcome the lack of hydrodynamic bearings and hydrostatic bearings of both. Major works: When the bearing Vice start or braking process, a static pressure to liquid lubrication, high pressure lubricating oil pressure into the bearing load zone, float axis Jin, to ensure the liquid lubrication conditions, thus avoiding the start or the braking process can not form a hydrodynamic oil film leaving the metal friction surface (surface of the journal and the bearing surface) direct contact with the friction and wear due to the speed change. Bearing Vice full-speed stable operation, the static pressure fuel supply system to stop, and with the formation of hydrodynamic oil film hydrodynamic lubrication oil, liquid lubrication conditions remain live journal bearing. This method, in theory, bearing start, running, braking, reversing the whole process completely avoid the semi-liquid and boundary lubrication, a liquid lubrication. Therefore, the friction coefficient is very low, as long as to overcome the frictional resistance between the liquid internal molecular lubricant viscosity on the line. In addition, the friction surface is completely hydrostatic oil film and hydrodynamic film separated therefore, if the situation is normal, almost no wear and tear, thereby greatly extend the working life of the bearing, saving the consumption of kinetic energy.
4. Boundary lubrication (boundary friction):
Boundary lubrication is the internal friction from the friction surface between the lubricant molecules and the intermolecular (ie, liquid lubrication) the transition to the critical state prior to the direct contact of the friction surface. Then the friction interface layer adsorption of the film thickness is usually about 0.1μm, with a certain amount of lubrication performance. We call this layer of thin-film boundary film. The boundary lubrication properties of the membrane depends on the nature of the friction surface; depends on the lubricant oil additives, extreme pressure additives on the structure of the boundary film formed on the surface of metal friction to the formation of the mouth of the lubricating oil viscosity relationship.
5. Extreme pressure lubrication:
Extreme pressure lubrication is a special case of boundary lubrication is the friction layer of Deputy Director in the overloaded (or high contact stress), high-speed, high temperatures, extreme pressure lubricant additives and metal friction surface from the reaction The chemical reaction film, the two friction surfaces separated, and play a lower coefficient of friction, slowing the wear and tear (or change the severe wear of metal surfaces in direct contact), the role of lubrication, it is called extreme pressure lubrication.
6. Solid lubrication:
Between the friction surface into the solid lubricant of the powdered substance, also can play a good lubricating effect. Solid lubricant between the two friction surfaces, the shear resistance is very small, a slight external force, intermolecular slippage. This will put outside the friction between the two grinding into the internal friction between the solid lubricant molecules. There are two necessary conditions for solid lubrication, the first solid lubricant molecules should have a low shear strength, it is easy to slip; solid lubricant with a friction surface has a strong affinity, in the friction process, always the friction surface has always maintained a layer of solid lubricant, and this layer of solid lubricant is non-corrosive friction surface. General mechanical adhesion on metal surfaces, but also the formation of chemical bonding with the above-mentioned nature of the solid material, such as graphite, molybdenum disulfide, talc, etc. For non-layered structure of a solid lubricant or soft metal, its shear stress is low, the grease, then make it attached to the friction surface to form a lubricating film. Has formed solid lubricating film lubrication mechanism can explain the lubrication approximation of the boundary lubrication mechanism.
7. Self-lubricating
The above-mentioned several lubrication, friction movement process, to the friction between the surface by adding lubricant. Merger by the suppression of self-lubricating sucked lubricating properties of solid lubricant powder and other solid materials mixed sintering timber, or immersed in a porous material with solid lubricant; or solid lubricant directly suppress the finished product, as friction surface. So that the entire friction process, do not need to add lubricant, still has a good lubricating effect. Self-lubrication mechanism includes the solid lubrication, boundary lubrication, or both. Such as compressor piston rings made of PTFE products, bearings, bushings are self-lubricating, so the process of such parts, it does not require together with any lubricant can maintain good lubrication.
1. The hydrodynamic lubrication:
Into the friction surface by the rotation of the bearing Vice journal lubricating oil, hydraulic fluid dynamic action of the wedge-shaped gap formation of the lubricating oil viscosity and oil bearing Vice, namely the formation of the bearing oil film, called hydrodynamic lubrication. Assumptions of hydrodynamic lubrication theory is the viscosity of the lubricant, the viscosity of the lubricating oil at a certain temperature does not vary with changes in pressure and change; followed by the assumption that students relative friction movement of the surface is rigid, ie by upload and film pressure, without regard to its elastic deformation. Under the above assumptions, the general non-overloaded (sliding bearing contact pressure of 15MPa), this assumption is close to the actual situation. However, in the rolling bearing and gear surfaces contact pressure increased to 400 ~ 1500MPa, the above assumptions with the actual situation. Then the deformation up to the film thickness of the friction surface several times, and the elastic deformation of the metal friction surface lubrication and lubricants viscosity change with pressure of these two factors, to study and calculate the pattern and thickness of the film formation, film cross-section shape and The pressure distribution within the film more with the actual lubrication on called elastic hydrodynamic lubrication.
2. Static pressure lubrication:
By a high-pressure hydraulic oil supply system will have a certain pressure of lubricating oil to the holidays flow damper, forced for the gap of the friction surface of the deputy campaign (such as hydrostatic slide bearing clearance, the plane hydrostatic slide guide the gap, the gap medium static pressure screw). Not yet started the movement, the friction surface by high-pressure oil separated, forced to form a film, thus ensuring the deputy campaign can withstand a certain load conditions, completely in the state of the liquid lubrication, the lubrication is called hydrostatic lubrication.
3. Dynamic, static pressure lubrication:
With the development of science and technology in recent years in industrial production, a new type of dynamic and static pressure lubricated bearing. Hydrodynamic, hydrostatic joint bearings give full play to the advantages of hydrodynamic bearings and hydrostatic bearings of both, to overcome the lack of hydrodynamic bearings and hydrostatic bearings of both. Major works: When the bearing Vice start or braking process, a static pressure to liquid lubrication, high pressure lubricating oil pressure into the bearing load zone, float axis Jin, to ensure the liquid lubrication conditions, thus avoiding the start or the braking process can not form a hydrodynamic oil film leaving the metal friction surface (surface of the journal and the bearing surface) direct contact with the friction and wear due to the speed change. Bearing Vice full-speed stable operation, the static pressure fuel supply system to stop, and with the formation of hydrodynamic oil film hydrodynamic lubrication oil, liquid lubrication conditions remain live journal bearing. This method, in theory, bearing start, running, braking, reversing the whole process completely avoid the semi-liquid and boundary lubrication, a liquid lubrication. Therefore, the friction coefficient is very low, as long as to overcome the frictional resistance between the liquid internal molecular lubricant viscosity on the line. In addition, the friction surface is completely hydrostatic oil film and hydrodynamic film separated therefore, if the situation is normal, almost no wear and tear, thereby greatly extend the working life of the bearing, saving the consumption of kinetic energy.
4. Boundary lubrication (boundary friction):
Boundary lubrication is the internal friction from the friction surface between the lubricant molecules and the intermolecular (ie, liquid lubrication) the transition to the critical state prior to the direct contact of the friction surface. Then the friction interface layer adsorption of the film thickness is usually about 0.1μm, with a certain amount of lubrication performance. We call this layer of thin-film boundary film. The boundary lubrication properties of the membrane depends on the nature of the friction surface; depends on the lubricant oil additives, extreme pressure additives on the structure of the boundary film formed on the surface of metal friction to the formation of the mouth of the lubricating oil viscosity relationship.
5. Extreme pressure lubrication:
Extreme pressure lubrication is a special case of boundary lubrication is the friction layer of Deputy Director in the overloaded (or high contact stress), high-speed, high temperatures, extreme pressure lubricant additives and metal friction surface from the reaction The chemical reaction film, the two friction surfaces separated, and play a lower coefficient of friction, slowing the wear and tear (or change the severe wear of metal surfaces in direct contact), the role of lubrication, it is called extreme pressure lubrication.
6. Solid lubrication:
Between the friction surface into the solid lubricant of the powdered substance, also can play a good lubricating effect. Solid lubricant between the two friction surfaces, the shear resistance is very small, a slight external force, intermolecular slippage. This will put outside the friction between the two grinding into the internal friction between the solid lubricant molecules. There are two necessary conditions for solid lubrication, the first solid lubricant molecules should have a low shear strength, it is easy to slip; solid lubricant with a friction surface has a strong affinity, in the friction process, always the friction surface has always maintained a layer of solid lubricant, and this layer of solid lubricant is non-corrosive friction surface. General mechanical adhesion on metal surfaces, but also the formation of chemical bonding with the above-mentioned nature of the solid material, such as graphite, molybdenum disulfide, talc, etc. For non-layered structure of a solid lubricant or soft metal, its shear stress is low, the grease, then make it attached to the friction surface to form a lubricating film. Has formed solid lubricating film lubrication mechanism can explain the lubrication approximation of the boundary lubrication mechanism.
7. Self-lubricating
The above-mentioned several lubrication, friction movement process, to the friction between the surface by adding lubricant. Merger by the suppression of self-lubricating sucked lubricating properties of solid lubricant powder and other solid materials mixed sintering timber, or immersed in a porous material with solid lubricant; or solid lubricant directly suppress the finished product, as friction surface. So that the entire friction process, do not need to add lubricant, still has a good lubricating effect. Self-lubrication mechanism includes the solid lubrication, boundary lubrication, or both. Such as compressor piston rings made of PTFE products, bearings, bushings are self-lubricating, so the process of such parts, it does not require together with any lubricant can maintain good lubrication.
