Cleaning, installation and removal of rolling bearings

Rolling bearings are assemblies that support the rotation of the shaft. The rings and rolling elements are precision machined. Before the bearings leave the factory, in order to protect the surfaces of the raceways and rolling elements from rusting, antirust oil or 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 cleaned directly with gasoline or kerosene; if thick oil or anti-rust grease is used to prevent rust, light mineral oil, such as 10# engine oil or transformer oil, must be heated to melt and cool the grease, and then use gasoline or kerosene cleaning. Bearings with dust caps or sealing rings on both sides have been greased before leaving the factory, so there is no need to clean them during installation. Bearings coated with lubricating and anti-rust dual-purpose grease do not need to be cleaned during installation. During the cleaning and installation process, foreign objects should be strictly prevented from falling into the bearing, because tiny abrasive particles will cause wear between the rolling element and the raceway, increase noise and vibration. There are two main ways to install and disassemble the bearing. 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, and easily install the bearing on the shaft or push it into the seat inside the hole. When the pressurization method is adopted, the mechanical force or hydraulic force directly acts on the assembled and disassembled seat ring through a special device, and the assembly and disassembly force is never allowed to be transmitted through the rolling elements. Otherwise, it will cause indentation on the raceway and rolling element surface, increase noise and vibration, and cause damage. If heating or cooling is used for assembly and disassembly, the heating or cooling temperature should be strictly controlled. Because the strength of the bearing working surface is affected by the metallographic structure of the metal surface, too high temperature will cause tempering effect; too low temperature will cause embrittlement of the metal surface. Usually, the heating temperature should not exceed 100℃, and the lowest cooling temperature should not be below minus 50℃. Also consider heating evenly. Practice has proved that improper bearing installation is one of the causes of premature bearing damage. It is very difficult to assemble and disassemble the ferrule with interference. Therefore, when designing the bearing, it is necessary to consider how to assemble and disassemble the bearing and the ease of assembly and disassembly. For the assembly and disassembly of heavy machinery and large bearings, special equipment is often required. If the high-pressure oil is disassembled, the oil circuit, pipeline and pump need to be designed accordingly.