Common Disassembly Methods for Cylindrical Roller Bearings

Time：2020.07.24  Source：Roller Bearings Suppliers

Bearings are important parts of mechanical equipment. In the process of maintenance, reasonable disassembly methods should be obtained, and the bearings should be disassembled well, so as not to damage the bearings. According to ZZ Bearing (Shanghai) Co., Ltd. , To share common methods and importance of bearing disassembly.

Taking cylindrical roller bearings as an example, common methods for bearing disassembly are:

1. Unloading method: Use the impact energy generated when a hammer strikes a copper rod or soft iron to remove the bearing.

2. Drawing method: The drawing method should be used for the bearing parts with high precision that are not allowed to be knocked or cannot be disassembled by the unloading method. It is disassembled with a special puller.

3. Pressing method: use screw C-type chuck, mechanical press, hydraulic press or jack and other tools and equipment for disassembly, suitable for bearings with interference fit. Click here to learn more about ZZ NJ316EM.

4. Temperature difference method: The temperature difference method uses the thermal expansion and contraction properties of the material to heat the containing parts, so that the mating parts lose interference under the temperature difference condition and realize disassembly. Generally, special electric heaters matching the bearings are used.

5. Destructive method: If the bearing and the shaft or shell or sleeve are bitten to each other, or the auxiliary part is destroyed to save the main part, it can be destructively disassembled by cutting and other methods.

Depending on the type and structure of the bearing, the bearing removal methods are as follows:

1. Disassembly of the outer ring

Remove the outer ring, set several screws for extruding the outer ring on the circumference of the outer ring in advance, tighten the screws evenly on the surface, and remove them. These screw holes are usually covered with blind plugs and separable bearings such as tapered roller bearings. Several cuts are provided on the housing shoulders, using spacers, disassembled with a press, or tapped lightly.

2. Removal of cylindrical bore bearings

The disassembly of the inner ring can be pulled out with a press machine. But pay attention to let the inner ring bear its pulling force. The oil pressure method is adopted for the inner ring disassembly of large bearings. Oil pressure is applied through the oil hole provided on the shaft, making it easy to draw. For bearings with a large width, the hydraulic method and the drawing fixture are used together.

The inner ring of NU and NJ cylindrical roller bearings can be disassembled by induction heating. Need ZZ bearing NU219EM, please click here.

3. Removal of tapered bore bearings

Disassemble the relatively small bearing with adapter sleeve, support the inner ring with the stopper fastened on the shaft, turn the nut back several times, use the spacer block and hammer to remove it.

Large-scale bearings can be easily disassembled by oil pressure. Oil is pumped through the oil hole on the tapered shaft to expand the inner ring and then disassembled. In operation, it is better to use the nut as a stop.

The importance of correct disassembly of bearings:

1. The guarantee of reasonable and effective use of the bearing, so that the bearing can reach its due life, accuracy and other indicators;

2. Make the host meet the expected performance indicators of the design, such as safety, vibration, noise, maintenance cycle, etc.;

3. Reduce user expenses and costs.