Cleaning, installation and disassembly of rolling bearings
Rolling bearings are components that support the rotation of a shaft. The ferrules and rolling elements are precision processed. Before the bearing leaves the factory, in order to protect the surface of the raceways and rolling elements from being corroded, anti-rust oil or anti-rust grease is injected between the raceways and the rolling elements. Therefore, the bearing should be cleaned before installation. Bearings sealed with anti-rust oil can be directly cleaned with gasoline or kerosene; if thick oil or anti-rust grease is used to prevent rust, light mineral oil must be used first, such as 10# engine oil or transformer oil, to melt the grease and cool down, and then use gasoline Or kerosene cleaning. Bearings with dust caps or sealing rings on both sides have been greased with grease before leaving the factory, so they do not need to be cleaned during installation. Bearings coated with dual-purpose grease for lubrication and rust prevention do not need to be cleaned during installation. During the cleaning and installation process, foreign matter should be strictly prevented from falling into the bearing. Small abrasive particles will cause wear between the rolling elements and the raceway, increasing noise and vibration. Bearing assembly and disassembly are mainly through two ways. One is to press the interference ring into the shaft or into the bearing seat hole; the other is to heat the bearing to increase the inner diameter, or cool the bearing to reduce the outer diameter, so that the bearing can be easily installed on the shaft or pushed into the seat孔内。 In the hole. When the pressurization method is adopted, the mechanical force or hydraulic pressure directly acts on the seat ring to be assembled and disassembled through a special device, and the load and disassembly force is never allowed to be transmitted through the rolling elements. Otherwise, it will cause indentation on the surface of the raceway and rolling elements, increase noise and vibration, and cause damage. If heating or cooling methods are used for assembly and disassembly, the heating or cooling temperature should be strictly controlled. Because the strength of the working surface of the bearing is affected by the metallographic structure of the metal surface, too high a temperature will cause a tempering effect; if the temperature is too low, it will cause embrittlement of the metal surface. Generally, the heating temperature should not exceed 100℃, and the lowest cooling temperature should not be below minus 50℃. At the same time, the heating should be evenly considered. Practice has proved that improper bearing installation is one of the reasons leading to premature bearing damage. Assembling and disassembling a ferrule with interference is a very difficult task. Therefore, when designing the support, it is necessary to consider how the bearing can be assembled and disassembled and the ease of assembly and disassembly must be considered. For the assembly and disassembly of large bearings in heavy machinery, special equipment is often required. If the high-pressure oil is disassembled, the oil circuit, pipeline and pump must be designed accordingly.