Bearings are very important machinery components since they dominate machine performance. Almost all machines and mechanisms with a rotating part, from the smallest motor to the largest power plants, from turbomachinery to reciprocating engines, and other industrial equipment our modern society relies upon, could not function without the use of bearings in some form. If one of the bearings fail, not only do the machines stop, but the assembly line also stops, and the resulting costs may be extremely high. For this reason, every bearing manufacturer makes every effort to ensure the highest quality for each bearing and that the end user subjects the bearing to careful use and properly maintains this component.
A bearing can be defined as a machine element which supports another moving machine element (known as a journal). It permits a relative motion between the contact surfaces of the members, while carrying the loads (static and dynamic). Some consideration will show that due to the relative motion between the contact surfaces, a certain amount of power is wasted in overcoming frictional resistance. If the rubbing surfaces are in direct contact, there will be rapid wear. In order to reduce frictional resistance, wear, and in some cases to carry away the heat generated, a layer of fluid (known as lubricant) may be provided. This lubricant is used to separate the journal and bearing, which allows the moving parts to move smoothly and helps to achieve more efficient machine operation. Some of the common bearing types are shown in Figure 1.The main purpose of bearings is to prevent direct metal to metal contact between two elements that are in relative motion. This prevents friction, heat generation and ultimately, the wear and tear of parts. It also reduces the energy consumption required for moving parts. Additionally, they also transmit the load of the rotating element to the housing. This load may be axial, radial or a combination of both. Bearings also restrict the freedom of movement of moving parts to a predefined direction. With all these aspects, bearings are clearly important for the operations and the reliability of mechanical products. The right bearing can increase useful life of the machine, and enhance the machine’s overall performance. The wrong bearing can lead to premature failure, increased downtime, and increased wear and fatigue among all components of the machine. Read More