Cleanliness of the Lubrication Industry
As a result of the understanding that the cleanliness of the Lubrication Industry has a significant impact on the normal operation of machinery and equipment, there has been a degree of cleanliness control index for the Lubrication Industry, that is, well-known indicators of mechanical impurities, In the provisions of the sediment indicators. These two indicators are the low standard concept of cleanliness of the Lubrication Industry: they are measured by the weighing method, and the shape and size of the impurities can not be expressed.
With the increasing sophistication of mechanical equipment, triggering a new degree of awareness of the cleanliness of the Lubrication Industry, new requirements. To hydraulic oil as an example: modern hydraulic system servo mechanism is very precise (gap 3μm,) easily blocked by oil particles, resulting in control failure. Lubricants in the industry will reduce the reliability and service life of the equipment, so it is necessary to measure the degree of cleanliness of the oil in a more accurate way, called "cleanliness".
Standard for cleanliness of the Lubrication Industry
Currently widely used ISO 4406 and NAS 1638 regulations, there is a certain relationship between the two standards. China is equivalent to ISO 4406-1999 standard, the formation of "hydraulic transmission fluid solid particle pollution grade code" GB / T 14039-2202. ISO 4406-1991 standard is to determine per 100ml of oil> 5μm,> 15μm particles, and the revised ISO 4406-1999 standard is to determine 100ml oil> 4μm,> 6μm,> 14μm particles. The above criteria can also be converted into the number of particles per 1ml of oil (non-linear, logarithmic relationship). The ISO 4406 cleanliness standard has been presented by the International Organization for Standardization in 1991 for the identification of pollution levels (cleanliness). ISO 4406 The reason why the choice of 5μm, Lubrication Industry 15μm these two sizes, because the study shows that 5μm particles will cause serious wear and tear> 15μm is mainly caused by component stuck, so these two sizes can basically reflect the oil wear, Dead condition. The NAS 1638 Cleanliness Standard (published by the American Aerospace Industry Association in January 1984) is the largest number of particles to determine per 100 ml of oil. NAS 1638 is segmented and has 5 dimension segments (5 to 15 μm, 15 to 25 μm, 25 to 50 μm, 50 to 100 μm, 100 μm or more). As the actual oil level of the pollution level can not be the same, so the degree of cleanliness of the oil sample to be determined according to the highest level. But this will also cause some judgments, for example, measured 5 ~ 10μm cleanliness may be 4, 15 ~ 25μm particles cleanliness may be 5, to 50 ~ 100μm particles cleanliness may be 8, this When the data will be difficult to deal with, Lubrication Industry often makes the concept unclear. According to the foregoing provisions: according to the highest level of which sentenced, it should be set to 8, that is, the system is dirty. In fact, the new wear theory shows that only the size and component movement gap equivalent to the particles will cause serious wear and tear, that is 5 ~ 15μm particles the greatest harm, and 50 ~ 100μm due to the movement can not enter the gap, the impact of wear Not big. ISO 4406 and NAS 1638 two cleanliness standard system with a table, in the same particle size per milliliter of oil, the same number of particles can be found in the table from the two standards corresponding to the standard code.
Lubrication Industry should have good anti-wear, resistance to load performance and the appropriate viscosity. In addition, it should also have good thermal oxidation stability, anti-foam, water separation performance and anti-rust performance. As the gear load is generally 490 MPa, while the hyperbolic tooth surface load is higher, the amount of Lubrication Industry accounted for about 6% to 8% of the total amount of lubricants. The Lubrication Industry is an excellent lubricating oil.
Lubrication Industry to oil lubricants base oil or synthetic lubricants, adding extreme pressure anti-wear agent and oil agent made of an important lubricant. For a variety of gear transmission to prevent tooth surface wear, abrasion, sintering, etc., to extend its service life, improve the transmission power efficiency. And the hyperbolic tooth surface load is as high as 2942MPa, in order to prevent the oil film rupture caused by tooth surface wear and abrasion, in the Lubrication Industry often add extreme pressure antiwear agent, commonly used sulfur - phosphorus or sulfur - phosphorus - nitrogen additives.
Lubrication Industry generally requires the following six basic performance:
1, the appropriate viscosity and good viscosity temperature, viscosity is the most basic performance of the Lubrication Industry. Viscosity, the formation of thicker oil film, anti-load capacity is relatively large.
2, enough extreme pressure anti-wear
Extreme wear resistance is the most important nature of the Lubrication Industry, the most important features.