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Common fractures and characteristics of bearing inner rings

wallpapers Tech 2020-12-11

When the stress acting on the bearing ring is greater than the tensile strength of the material or the fatigue strength limit of the material, it will cause the ring to crack. The crack will eventually expand to a certain extent and cause a part of the part to be completely separated, which is called cracking or fracture. Analysis of the reasons surrounding the topic of fracture:

 

Improper coordination mainly has the following three situations that can easily cause the inner ring to break:

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1. The interference is too large

When the interference between the inner ring and the shaft is too large, the inner ring cracks in two stages;

 

A: After the bearing is hot-fitted to the roll neck, cracks occur during the cooling process of the inner ring before being used on the machine.

 

B: After the bearing is hot-fitted to the roll neck, cracks occur during the outer diameter grinding before the machine is used.

 

2. The interference is too small

When the interference between the inner ring and the shaft is too small, the inner ring cracking generally occurs in two stages;

 

A: When the bearing is used on the machine, the inner ring and the shaft have relative sliding friction, which causes the inner ring to crack.

 

B: During the operation of the bearing, the expansion of the inner ring is greater than the expansion of the roll neck at the initial stage. When the rolling mill bites and throws steel, the impact load causes the inner ring to burst.

 

3. Friction of end face mating parts

A: During the use of the bearing on the machine, the inner ring and the distance ring have relative sliding friction, which leads to the fracture of the inner ring and the crack of the inner ring.

 

B: When the bearing is running on the machine, the inner ring and the moving labyrinth and the fixed distance ring have relative sliding friction at the same time, which causes the fracture of the section to cause the inner ring to crack.

4. In addition to the breakage of the inner ring caused by the above-mentioned unblocking, special attention should be paid to the surface condition of the roll neck that matches the inner ring.

The inner ring of the bearing is fitted to the roll diameter by shrink fit. However, the surface defects of the roll diameter often lead to the destruction of the interference fit, resulting in problems such as cracking of the inner ring, locking of the bearing, and burning of the roll diameter.

 

A: The surface of the roll neck sinks and the chamfer (non-contact stress area) is raised.

 

B: Irregular wear and irregular taper.

 

Wuxi Spark Bearing Co., Ltd is a complete, one-stop bearing supplier and manufacturer. All bearings products are qualified and have passed the ISO 9001 certification. We have more than 12 years of experience in bearings, please contact us if necessary, we will reply to you as soon as possible.

 


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