What are the Different Types of Bearings ?
Bearings have been in use since the ancient Egyptians. The earliest use of bearings can also be traced to just after the invention of the wheel. You need a plain bronze bearing or other types of bearing when there is a relative motion between two surfaces. Bearings are used in many household appliances and industrial machinery.
A bearing carries a load when it moves relative to another part. It can be a rotating or sliding movement. The following are the most common types of bearings:
- Roller bearings
- Plain bearings
The following are other types of bearings:
- Fluid bearings
- Magnetic bearings
- Hinge-like flexure bearings
- Jewel bearings
Plain Bearing Types
A plain bearing is also known as a sleeve bearing. It is also known as bushings or bushes. This cylindrical component does not have any moving parts. You can also customize bearings in different shapes, designs, dimensions, and features such as holes, grooves, tabs, notches, etc.
This type of bearing is used for rotating, sliding, reciprocating or oscillating motion. The construction may be a split joint or solid. You have to consider the application to choose the right bearing. Consider the type, size, and material when you choose a bearing. In the case of high loads, choose a bronze bearing with a high load-bearing capacity and more contact area. A bearing operating at a higher temperature uses solid lubricants. Friction and heat build-up is high in high-speed applications. The selection of a plain bearing depends on performance requirements and operating conditions.
Low Friction Bearing Materials
A metal-polymer plain bearing is metal-backed. The metal can be bronze or steel. A porous bronze layer is sintered onto it. A running surface is obtained by impregnating with PTFE and additives. The surface is wear-resistant and anti-friction. This type of bearing can operate with or without external lubrication.
Engineered plastic is also used for making plain bearings. Engineered plastic has excellent low friction and wear resistance. You can use it in both lubricated and dry conditions. These bearings are injection molded. A bearing can be made using a variety of resins. It can be made in any shape. The dimensional stability of these bearings is excellent. They also have low thermal conductivity and coefficient of friction.
Fiber Reinforced Composite Bearings
This type of plain bearing consists of fiberglass-impregnated, filament-wound, and epoxy backing. The structure of these bearings supports high dynamic and static loads. Its inert nature is perfect for corrosive environments.
Bimetallic, Monometallic, and Sintered Bronze Plain Bearings
These bearings are designed to be used in both land and underwater applications. Submerged applications have slow speed movements and high load.
Solid Bronze Bearings
It is impregnated with lubricant. A solid bronze bearing provides you with maintenance-free performance. Solid bronze bearings are suitable for high-temperature applications.
This type of bearing is also known as ball bearing as it utilizes cylindrical rollers or balls. It has baring rings or “races” containing these elements. This facilitates motion while minimizing resistance to sliding. This is the most common type of bearings suitable for both radial and axial loads. However, this type of bearing is subjected to brinelling and other failure modes. Balls are deformed due to overloading. Due to the load, the rolling element deforms the race. As a roller bearing is designed to bear heavier loads, they have greater contact with the races. The weight is distributed over a larger area. However, this bearing is not suitable for applications that involve thrust loads.
Roller and Needle Bearings Versus Plain Bearings
- Rolling-element bearings are more expensive than plain bearings because of their multi-component design.
- A roller-bearing is suitable for applications that require precision and low friction.
- Plain bearings are suitable for applications with higher load capacity. These bearings have a greater contact area.
- Plain bearings have a slim, one-piece design to reduce housing size.
- A plain bearing resists damage due to oscillatory movements. This improves bearing life.
- When the load is too low and operating speed is high, rolling-elements skidding can cause wear damage. You don’t have to worry about such damage in a plain bearing.
- Plain bearings don’t have internal moving parts. The operation is quieter. When the system is properly lubricated, the speed rating is unlimited.
- A plain bearing is simple and straightforward to install as compared to rolling-element bearings.
- Corrosion resistance is high in non-metallic bearings.