When using bearings, early damage is a common fault, and there are various forms of early damage to bearings, such as improper bearing fitting, installation, and maintenance, all of which can cause early damage. The following are the early damage phenomena caused by improper bearings.

1. Damage caused by non-conforming size, shape, and positional accuracy of the workpiece in conjunction with the bearing

If the shoulder of the workpiece shaft and the housing hole are not perpendicular to the mating surface, or if the roughness of the bearing positioning surface is not qualified, and if the shaft is bent, it will cause the axis of the inner and outer rings of the bearing to tilt each other and significantly increase the local contact stress between the ring and the rolling surface of the roller, resulting in fatigue peeling and early damage.

If the hole of the workpiece shell is elliptical or conical, it will cause deformation of the ring and endanger the raceway, leading to premature wear and fatigue failure of the raceway. Similarly, if the geometric shape of the mating journal between the workpiece shaft and the bearing is incorrect, it will also cause damage to the inner raceway of the bearing. If the shaft diameter is too large, it may cause the inner ring to rupture. If the outer shell aperture is too large, it may cause the outer ring to loosen and slip, thereby exacerbating the wear of the outer shell aperture and outer ring diameter.

2. Improper installation operation causing damage to bearings

The inner components and outer rings of tapered roller bearings are installed on the shaft and inside the housing, respectively. During assembly, damage to the raceway and rollers can occur due to tilting, impact, or excessive assembly force. Even if the damage is small, it can exacerbate the damage to the raceway. If there are scratches on the rollers, the rotation of the bearing will also cause damage to the raceway of the ring.

If the bearing assembly is carried out by pressing in during the installation process, a specialized sleeve tool must be used, because directly tapping the ring with an iron rod may cause cracks or damage to the end face of the ring, and even cause the inner ring edge to crack. To avoid the occurrence of cracks, it is not advisable to directly strike the ring with an iron rod during installation, but a copper pad must be added.

When using specialized sleeve tools for the assembly of internal components, attention should be paid to the inner and outer diameter dimensions of the sleeve to avoid the sleeve being pressed against the end face of the cage, causing deformation of the cage. Severe deformation may result in roller scattering.

If the components inside the bearing are accidentally dropped to the ground or collided during transportation and assembly, it will cause deformation of the retaining frame. The deformed retaining frame will cause the rollers to get stuck, affecting the rotational flexibility of the bearing, resulting in heating and burning, ultimately leading to bearing failure.

The adjustment of the clearance between the outer ring and the inner components after bearing installation is also very important. If the clearance is too small, it will cause excessive temperature rise, accelerate wear and even bite; Excessive clearance will result in additional radial runout and axial displacement, causing relative displacement between the roller and the outer race raceway and resulting in uneven local wear and noise. Only by adjusting appropriately can the bearing operate normally.

3. Damage caused by improper use and maintenance

When the bearing is working, if the lubricating oil is insufficient, direct contact between the metal on the working surface will cause scratches, heat generation, and burns, reducing the original hardness of the bearing and causing adhesive wear, ultimately leading to bearing failure.

If the workpiece is not cleaned thoroughly or the lubricating oil added is not clean (such as mixed with sand, dust, dirt, etc.) before bearing installation, or if the sealing is unreliable and working in a dusty environment, some hard particles entering the bearing raceway will cause abrasive wear, resulting in fine groove marks or small pits on the surface, increasing the clearance of the bearing, reducing accuracy, and shortening the service life.

If bearings are subjected to excessive static or impact loads during use, it is likely to cause uneven plastic deformation - indentation - at the contact between the inner and outer rings and the rollers. The appearance of indentation will increase the vibration and noise of the bearing, raise the temperature, intensify wear, and ultimately cause severe peeling, leading to bearing failure. This situation often occurs on bearings with low rotational speed or swinging.

Bearings work in damp media and environments with acidic vapors and other substances that can cause metal corrosion. Poor sealing of bearings may result in rusting. The mixture of rust products and lubricating oil can cause corrosion and wear on the working surfaces of the raceway and rolling elements, and lead to surface peeling. If there is current passing through the bearing during use, the current may penetrate the bearing oil film, generate electric sparks, and cause surface melting, forming small pits or strip-shaped pits.

In order to ensure the normal operation and expected service life of bearings, necessary calculations should be made for the main failure modes of bearings when selecting them. For bearings that operate normally, their lifespan should be calculated based on contact fatigue failure and rated dynamic load; For high-speed bearings, in addition to calculating their lifespan, necessary limit speed checks must also be conducted; For bearings with lower rotational speeds, static strength calculations should be performed to prevent plastic deformation from occurring. After early failure of bearings, it is necessary to carefully observe the damage, analyze the causes, and take necessary improvement measures. In addition, the design of the bearing combination structure should be reasonable, ensuring sufficient lubrication and reliable sealing, which is very important for improving the life of the bearing and ensuring normal operation.