Lubrication Method of Main Bearing of Cement Ball Mill

The ball mill is the key equipment for crushing the material after it has been crushed. It is widely used in the production of cement, silicate products, new building materials, refractory materials, fertilizers, black and non-ferrous metal dressings and glass ceramics, dry or wet grinding of various ores and other grindable materials. The ball mill is suitable for grinding various ores and other materials.

The ball mill is the key equipment for crushing the material afterit has been crushed. This type of grinding machine is equipped with a certainnumber of steel balls as grinding media in its cylinder.

It is widely used in the production of cement, silicate products,new building materials, refractory materials, fertilizers, black andnon-ferrous metal dressings and glass ceramics, dry or wet grinding of variousores and other grindable materials. The ball mill is suitable for grindingvarious ores and other materials. It is widely used in mineral processing,building materials and chemical industries. It can be divided into dry and wetgrinding methods. According to different mining methods, it can be divided intotwo types: grid type and overflow type.

In cement production, ball mills are key production equipment. Themain bearing is one of the main components of the mill. The main bearing mustbe equipped with a reliable lubrication device. Large mills use oil pumps forforced circulation lubrication. Small mills can be lubricated with oil or oilspoons, but the lubrication is poor and the oil is not filtered.

The main bearing lubrication can adopt dynamic pressure anddynamic static pressure. This paper mainly introduces the dynamic pressurelubrication method of the main bearing. Dynamic pressure lubrication hasseveral forms such as oil pump oil supply and oil field oil.

Oil pump oil supply: Lubricating oil enters the bearing from theoil inlet pipe, sprays the oil onto the hollow shaft, and then brings it intothe bearing bush. The lubricating oil in the bearing seat flows back from theoil return pipe, and the closed circuit circulating oil supply system is formedby filtering, cooling and the like. The lubrication effect is good, and the oillevel hole is used to check the amount of oil in the fuel tank. Due to the lowrotation speed of the mill, the oil film formed by dynamic pressure lubricationis very thin, which does not achieve liquid friction lubrication, but issemi-liquid friction lubrication, and is equipped with a spare oil ring forcomplete reliability.

Small and medium-sized mills are often lubricated with oil ringoil: the oil is brought up by the oil ring, and the oil is distributed on thesurface of the hollow shaft and the bushing lining through the scraper rod. Thelubrication cooling effect is slightly worse than the oil pumping system, andthe lubricating oil is not filtered, but the structure is simple.

There are two main problems in dynamic pressure lubricationbearings: First, when the mill starts, the frictional resistance torque betweenthe journal and the bearing bush increases due to the disappearance of the oilfilm, which causes the starting load of the mill to be too large, and oftenscratches the surface of the bearing pad. Excessive starting load is not goodfor transmission parts such as motors and reducers.Second, when the mill stops running, the journal shrinks due tocooling, and the surface of the bearing pad is often scratched when the oilfilm disappears. In order to solve the above problem, before the mill isstarted, the high-pressure oil pump is used to supply oil from the bottom ofthe bearing bush, the shaft is floated, and then the mill is started. Inaddition, when the grinding is stopped, high-pressure oil is supplied to thebearing, and the shaft is floated, so that the shaft is freely contracted inthe bearing bush until cooling, so as to protect the bearing bush from beingscratched.