Ultimate Guide To Types Of Bearings

Manufacturers produce bearings in different types to best suit each application and industry. This guide is curated to give you an in-depth knowledge of the types of bearings.

Meaning Of Bearing

Bearing is a mechanical part that facilitates rotation in mechanical objects. In other words, the bearing is a mechanical part that restricts relative motion and minimizes friction between two moving mechanical parts. You’ll find them mostly in machine components because they have rolling elements that make movement easier while reducing friction.

How Does A Bearing Work?

Bearing works by minimizing the rate of friction by providing smooth balls or rollers, as well as smooth inner surfaces and outer surfaces for the balls to roll against. The device then spins smoothly due to the ability of the balls or rollers to bear the loads. In other words, the bearing gives rotation to the device, thus resulting in minimized friction between the bearing and its tumbling surface. When there’s a reduction in friction, it’s easier to move rotationally or linearly, thus resulting in efficiency and speed.

Bearing Types And Their Characteristics

Ball Bearings

They have balls that serve as their rolling elements. Ball bearings feature ball contact between the balls and the raceways. Ball bearings are the best type of bearing because they have fast rotation, but they cannot withstand substantial loads. In addition, ball bearings are the most popular and widely used bearings. They have rolls of balls that are enclosed between two annular-shaped races that serve as rolling elements. The inner race rotates freely, while the outer race is stationary.

Features:

• Robust and durable
• Less susceptible to corrosion
• Highly resistant to heat and temperature.
• Have mechanical stability.
• Possess a low coefficient of linear expansion.

Roller Bearings

This type of bearing features a cylindrical rolling element between the races instead of balls as the load-carrying element. When the length of an element is longer than its diameter, it’s considered a rolling element even if it surpasses it slightly. Unlike ball bearings that are in point contact, roller bearings are in line contact with the inner and outer races, thus making the load type of roller bearing greater than that of ball bearing.

Features:

• Improved bearing rigidity.
• Vibration and noise reduction.
• Function for a longer time without experiencing wear and tear.
• Lower starting friction coefficient.
• Last longer even in humid or corrosive environments.
• Function in either high or low application.
• One roller bearing is capable of carrying both axial and radial loads at once.

Plain Bearings

This is the simplest type of bearing. They have a bearing surface with no rolling elements. Another name for plain bearing is “sleeve bearing” because the bearing is a sleeve mounted on a shaft and it fits into the bore. They are lightweight, compact, and inexpensive. In addition, they are capable of carrying high loads. Lastly, plain bearings are good for oscillatory or reciprocating, rotational, or sliding motion.

Features:

• Durable
• Low friction
• Low wear to the bearing and shaft
• Resistance to high temperature
• Resistant to a corrosive environment
• Often made up of at least two constituents (one hard, one soft.)

Fluid Bearing

This type of bearing carries loads and eliminates friction with liquid or pressurized gas. Instead of using metallic bearings in applications where a short lifespan is guaranteed in addition to high noise and vibration, fluid bearings can be utilized instead. In conclusion, fluid bearings perfectly fit machines that require high speed and load, and they are affordable.

Features:

• Low friction
• High load capacity
• Long lifespan
• High Accuracy

Magnetic Bearing

They help to hold the shaft mid-air with the concept of magnetic levitation. This type of bearing are zero-wear bearing due to their nonphysical contact. For example, they are low friction and have no mechanical wear bearing, thus making them capable of levitating a rotating shaft and making relative motion accessible. In addition, magnetic bearings support the highest speed and are not limited to a particular amount of relative speed.

Features:

• High-speed rotation.
• Low vibration and noise.
• Minimal power loss at high speed.
• Rotating parts do not need to be replaced.
• Support the shaft without making contact.
• They have sensors for observing the shaft position.

Applications Of Different Types Of Bearings

Ball Bearing

Household Items: Ball bearing types are applicable to the following household items; tumble driers, bicycles, sewing machines, washing machines, DVD players, fishing rods, hair dryers, food processors, etc.

Office Equipment: Photocopiers, air-conditioners, hard drives, fax machines, fans, etc.

Industries: Paper-making machinery, medical and dental equipment, chain saws, pumps/compressors, power tools, high-speed machining tool equipment, escalators, elevators, trains, wind turbines, assembly lines, toy manufacturing trains, etc.

Automotive: Electric motors, gearboxes, transmissions, engines, driveshaft and driveline, steering, etc.

Roller Bearing

Roller bearing are applicable to a diverse range of applications like construction and mining equipment, axle systems, gearboxes, agriculture, propeller shafts, differential, wind turbines, engine motors and reducers, railroad axle-box, sports robot combat, construction and mining equipment, agriculture, continuous casting machines, pumps mechanical fans and blowers, material handling, pumps, pulp and paper processing equipment, off-road vehicles, marine propulsion and off-shore drilling, rotary dryers, crushers, electric motors, blowers and fans, gears and drives, plastics machinery, automotive power transmission system, two and four stroke engines, etc.

Plain Bearing

You’ll find plain bearings in applications like; Ship propeller shafts, power plant steam turbines, compressors working in critical pipeline applications, ship propeller shafts, vehicles, mountain bikes, medical technologies, excavators, dump trucks, tractors, etc.

Fluid Bearing

Fluid bearings apply to the following; heavy machinery like marine propeller shaft, heavy-duty, heavy machinery such as marine propeller shaft, as well as hydroelectric plants to support turbines and generators, compressors, electric generators, hard disk drive, etc.

Magnetic Bearing

The application of magnetic bearings includes but is not limited to Petroleum refinement, machine tool operation, natural gas handling, electrical power generation, Zippe-type centrifuge, turbomolecular pumps, compressors, turbines, pumps, motors, and generators, watt-hour meters, etc.

Factors To Consider Before Choosing The Type Of Bearing

Load

You can measure bearing load in several ways. The shaft is subjected to radial load at the proper angle. You can also measure the forces acting in the same direction as the shaft using axial load. In this system, radial and axial loads can cooperate to create a moment or combined load. All three forms of loads must be supported by a bearing throughout its anticipated range.

Speed

Each bearing is designed to function optimally within a certain speed range. Different bearings are required for a system that travels quickly versus one that moves slowly. If high-speed bearings are somewhat misaligned, they still need to function safely, and this might have a considerably greater impact when turning swiftly.

Temperature

Understanding how temperature variations impact a rotating system’s components is essential to getting the most out of it. Journal bearings can generate a great deal of heat in a system, and it’s crucial to understand how they respond to heat from other sources. The lubrication of the bearing needs to be adjusted for the temperatures at which it will be used.

Tolerance

The fit and rotational performance of cylindrical roller bearings with spacers is governed by ISO and JIS standards. For machines that require great precision and speed of operation, pathways with an accuracy level of 5 or higher are the most effective. Deep groove ball bearings, radial thrust ball bearings, or cylindrical roller bearings can all be used in machinery that must operate with extreme precision.

Accuracy

The majority of journals with O-level tolerance bearings are sufficient to satisfy the host’s requirements. Higher tolerance deep groove ball bearings should be utilized. Nevertheless, in applications where the accuracy of the shaft’s rotation is crucial, such as in machine tool spindles, precision machinery, and instruments.

Rigidity

Most of the time, this little shift can be disregarded. On the other hand, the static and dynamic stiffness of the bearing significantly influences the operation of certain equipment, such as machine tool spindle systems.

Friction Torque

Unlike roller bearings, ball bearings are less resistant to friction. When a radial contact bearing is subjected to a pure radial load, the friction resistance is minimal. When an axial contact bearing experiences a pure axial load, friction resistance frequently occurs. Selecting a journal bearing is not complete until the industrial maintenance services for the long run are looked at.

Conclusion

In conclusion, there is a diverse range of bearings that are manufactured to cater to different needs in various applications and industries. While ball bearings are the most widely used, some applications require another type of bearings for optimized functionality.