Knowledge on gear oil classification

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Gear oil is a lubricant with relatively high viscosity, designed specifically to protect components that transmit power; it has a very strong, sulfurous odor. The classification method for gear oil is based on two factors: performance and viscosity. Currently, the API performance classification system of the American Petroleum Institute and the specifications for military gear oils in the United States are widely used around the world. Gear oils are divided into two categories: automotive gear oils and industrial gear oils. Industrial gear oils are classified into types such as L-CKB for oxidation and rust prevention, L-CKC for extreme pressure, L-CKD for extreme pressure, and L-CKE for turbines and worms. Automotive gear oils are classified into GL-1 for general use, GL-2 for turbines, GL-3 with medium extreme pressure, and so on. Meaning of gear oil grades: Ordinary gear oils are classified into three grades – 20, 26, and 30 – based on their dynamic viscosity at 100 degrees Celsius. Hyperoid gear oil is classified into 4 grades, namely 18, 22, 26, and 28, based on its dynamic viscosity at 100 degrees Celsius. Based on quality, it is divided into three categories: the first category is conventional vehicle gear oil CLC, medium-load vehicle gear oil CLD, and heavy-load vehicle gear oil CLE. The model grade classifications include GL-1, GL-2, GL-3, and so on. For gear oil, when the dynamic viscosity and apparent viscosity at 100 degrees Celsius are 150,000 MPA·S, the highest operating temperature corresponds to seven viscosity grade specifications: 75W, 75W/90, 80W/90, and so on. By understanding the above information, it is easy to know various parameters and uses of gear oil. Selection of gear oil type: The choice of gear oil type depends on various factors such as the type of gears, their operating speed, transmission ratio, working environment temperature, load, drive type, and more. It is important to know that when the temperature drops, the lubricant becomes thicker, while when the temperature rises, it becomes thinner. Therefore, low temperatures require lubricants with low viscosity, while high temperatures require lubricants with high viscosity. Also, the faster the sliding speed and rotational speed of the gears, the less lubricating oil there is between them; therefore, it is most appropriate to use lubricating oil with high viscosity at low speeds and lubricating oil with low viscosity at high speeds. High load pressures require lubricants with high viscosity, while low loads require lubricants with low viscosity.