How Load-Carrying Capacity Affects Bearing Service Life
Galvanized Steel Sheet,Galvanized Steel Plate,Galvanized Iron Steel Sheet,Galvanized Mild Steel Plate Shandong Rizhaoxin Metal Products Co., Ltd. , https://www.changyisteel.com
Bearings, much like people, experience stress. Choosing the right bearing means ensuring it can handle the pressure without "getting stressed out." In other words, it's crucial to match the bearing's load capacity with the actual forces it will encounter during operation.
When a bearing is subjected to a load that exceeds its capacity, it can lead to premature wear, fatigue, or even permanent deformation, significantly shortening its lifespan. Two main types of stress must be considered when selecting a bearing: static and dynamic.
Static stress occurs when a load—whether constant or variable—is applied to a bearing that is either stationary or moving very slowly. Even though the load may not be moving, the bearing itself is in a static state. If the load is too heavy, it can cause plastic deformation on the rolling surfaces or even flatten the rolling elements, leading to early and potentially catastrophic failure.
Dynamic stress, on the other hand, happens when a load is applied to a rotating bearing. This type of stress is related to the motion of the bearing rather than the nature of the load. If the load is too high for the bearing’s capacity, it can cause fatigue damage, resulting in cracks and flaking on weak points of the bearing. This eventually leads to failure due to material fatigue.
There are three primary theories that explain how fatigue causes bearing failure. The maximum shear stress theory suggests that the main cause is the highest shear stress within the bearing. The distortion theory claims that stress distribution across a region, rather than at a single point, leads to fatigue. The alternating shear stress theory, however, states that orthogonal stresses on the bearing surface are the key factor in material fatigue.
While each theory has some support, the alternating shear stress theory is widely used in calculating the fatigue life of rolling bearings. The fatigue life, also known as the rating life, is defined as the number of revolutions or hours a bearing can operate at a constant speed before 10% of a group of identical bearings show the first signs of material fatigue. Generally, as the load increases, the rating life decreases.
At Emerson Bearing, our team of experts is here to help you select the right bearings for your application, ensuring they don’t get “stressed out.†We offer comprehensive support for all your bearing needs. Contact us today, or visit our **Catalog** and **Technical Toolbox** pages for more information on how we can assist you.