Introduction to Key Points and Techniques for Bearing Installation and Disassembly

In order to ensure the stable operation of the bearing system and achieve the expected service life, it is necessary to install the bearings correctly. If not installed correctly, the bearings will be damaged prematurely, which can affect the machine's user experience, increase noise and heat, and in severe cases, cause the machine to shut down, cause property damage, and pose a health hazard to the user. This article introduces some key points and techniques for bearing installation and disassembly, hoping to help everyone.

When replacing bearings, the first step is to remove the faulty bearing. The best choice is to use a puller and press, as shown in the above figure. Using a puller to safely pull the bearing out of the outer ring can minimize damage to the shaft and housing and save time.

In addition to the puller, bearings can also be disassembled using a separator. The separator is designed with two plates placed behind the bearings, and the bearings are pulled out by applying force to the plates. If heavy bearings need to be disassembled, the separator can use hydraulic auxiliary oil cylinders for power supply.

It is not recommended to reuse the removed bearing, but it needs to be carefully inspected to determine the cause of bearing failure, summarize experience, and use it to protect the bearing in future use. Some bearing damages cannot be seen with the naked eye, and advanced analysis tools may be needed to determine the cause of the fault.

The dismantled bearings can be sent back to the manufacturer, who will clean, inspect, measure, and regrind the bearings. If they meet the conditions for reuse after inspection, they can be reused. This can save a lot of money when dealing with some large and expensive bearings.

When installing new bearings, special care should be taken to ensure a clean, dry, and vibration free storage space. Before installing the bearings, do not open the bearing packaging. Unless required by the instructions, do not wipe or clean the pre filled lubricating oil or grease from the factory before installation.

Before starting installation, it is necessary to ensure that the bearing housing and shaft are clean and free of burrs. Diamond sand can be used for polishing, but particles generated by diamond sand paper may also contaminate the bearings. It is recommended to consider using an industrial transparent polishing pad to clean the shaft and housing, and then use light engine oil to remove moisture. The bearing must be kept clean throughout the entire process.

During installation, it is necessary to ensure that the shell holes and shafts are also measured to ensure they are within the recommended tolerance range of the bearing and machine. It is recommended to use tools such as vernier calipers or micrometers for measurement. The amount of force used during bearing installation depends on the type and degree of fit. In many applications, such as motor shafts, the inner ring requires an interference fit, while the outer ring requires a clearance fit.

If the bearing diameter is less than 50mm and its inner ring is installed with a mild interference fit, consider using a bearing driver. The driving tool consists of a solid hammer, polymer impact ring, and metal tube. The tube driver is versatile and can be used with oil seals, oil seals, and bushings.

It is necessary to ensure the use of a safety press firmly fixed on a sturdy workbench. The bracket should be used together with a long handle to exert leverage. Press down on the handle and use an anvil to apply pressure to the handle, slowly supporting the machine.

In order to easily remove bearings, the principle of thermal expansion and contraction can be used to raise or lower the temperature of the bearing, housing, or shaft, so as to separate the bearing from the shaft and housing and facilitate bearing removal. It is necessary to ensure that the housing and shaft are clean and free of burrs, and correct measurement is required to ensure that the dimensions of the housing or shaft are within the recommended range. If they exceed the recommended range, replacement is necessary.

Induction heaters can be used to heat bearings. Compared to other methods, induction heaters are safer, cleaner, and more efficient. Induction heaters generate strong magnetic fields, induce eddy currents on the metal shaft, connect secondary coils to transmit low AC current, and bearings are used for short circuits. The effect is that the collar near the rod heats faster, requiring multiple heating of the bearings.