What are the symptoms of rolling bearing failure

1. Fatigue peeling

The inner and outer raceways of rolling bearings and the surface of rolling elements both bear load and roll relatively. Due to the effect of alternating load, cracks are formed at a certain depth below the surface (shear stress), and then extend to the contact surface to cause peeling pits on the surface, and then develop to large flakes. This phenomenon is fatigue peeling. Fatigue flaking will aggravate impact load, vibration and noise during operation.

2. Wear

Due to the invasion of dust and foreign matters, the relative movement of the raceway and rolling body will cause surface wear, and poor lubrication will also aggravate the wear. As a result of wear, the bearing clearance will increase, the surface roughness will increase, and the bearing operation accuracy will be reduced, which will also reduce the movement accuracy of the machine, and the vibration and noise will also increase. For mechanical bearings, it is often the amount of wear that limits the life of the bearing.

3. Plastic deformation

When the bearing is subjected to excessive impact load or static load, or additional load caused by thermal deformation, or foreign matters with high hardness invade, dents or scratches will be formed on the raceway surface. This will cause severe vibration and noise during the operation of the bearing. Moreover, once there is indentation, the impact load caused by indentation will further cause the peeling of the nearby surface.

4. Rust

Corrosion is one of the serious problems of rolling bearings. High precision bearings may lose their accuracy due to surface corrosion and cannot continue to work. The direct invasion of water or acid or alkaline substances will cause bearing corrosion. When the bearing stops working, the temperature of the bearing drops to the dew point, and the moisture in the air condenses into water drops attached to the bearing surface, which will also cause corrosion. In addition, when there is current passing through the bearing, the current may pass through the contact point on the raceway and the rolling element, and the thin oil film may cause electric spark to produce electric corrosion, forming washboard like bumps on the surface.

5. Fracture

Excessive load may cause fracture of bearing parts. Improper grinding, heat treatment and assembly will cause residual stress, and excessive thermal stress during operation will also cause fracture of bearing parts. In addition, improper assembly method and process may also cause block falling at the bearing ring rib and roller chamfer.

6. Gluing

When working under the conditions of poor lubrication and high speed and heavy load, bearing parts can reach very high temperature in a short time due to friction heating, resulting in surface burns and gluing. Gluing refers to the phenomenon that the metal on the surface of one component adheres to the surface of another component.

7. The cage is damaged

Improper assembly or use may cause the cage to deform, increase the friction between it and the rolling element, or even make some rolling elements stuck and unable to roll, or cause friction between the cage and the inner and outer rings. This damage will further aggravate vibration, noise and heat, resulting in bearing damage.