Complete Guide to Bearings: Types, Uses, and Selection

Most motion machines use mechanical components to transfer force and motion. One such component used is bearings, which enable the rotational movement of the devices. The constant rubbing or contact of two metal parts of a machine produces wear and tear over time. However, bearings help reduce the friction between the moving parts of the equipment to increase its efficiency and speed.

Want to know more about how bearings work? This guide will explain all you need to know about the definition and purpose of bearing and its uses.

What is a Bearing?

A bearing is a vital mechanical component in the machine industry as it aids rotation between two or more parts of a machine. It is an inside equipment used with shafts to transfer motion and restrict friction. Its intricate design allows mechanical parts to rotate around an axis or move in a linear motion, ensuring smooth operation.

Bearings are often found in common household devices such as vacuum cleaners and refrigerators. In addition, they are commonly found in machining equipment like CNC lathes, drilling machines, etc, because they support the rotation of the shaft.

The Role and Importance of Bearings in Machinery

Although the primary function of bearings is to ensure there is no direct contact between motion elements, there are other roles of bearing. Some of the major roles of bearings in machinery are:

Facilitate Smooth Motion Or Rotation

One of the major roles of bearings in machinery is in the reduction of friction between its moving parts, such as the rotating axis and support part. It prevents single-point contact in machines by distributing load across other rolling elements. This reduces wear and tear on the machine while also allowing for a smoother motion.

Increase Efficiency

Bearings are a vital part of machines because they ensure the effective distribution of loads between the moving parts. They increase machine efficiency by reducing the power or energy lost due to friction. It also reduces the friction between the mechanical parts of the machine in motion by supporting the load and other rotating machine components to improve efficiency.

Improve the Longevity and Durability

Because bearings are available in different shapes and sizes, they are suitable for several types of equipment. This makes them suitable for several machines. It reduces the frequent need for maintenance of those machines.

In addition, bearings increase the lifespan of the machine as they prevent damage or catastrophic failure of the machine. However, it is vital to maintain bearings to improve the performance of the machinery.

Reduces the Maintenance Costs

Another importance of bearings in machinery is that they reduce the operating or maintenance costs of the machine. They serve as an economical solution because they reduce the frequency of machine repairs. Since bearings reduce wear and tear on machine components, they improve their performance level.

Ensure the Rotation Shaft is in Place

With bearing, the rotating shaft of the machine is held in place, thereby preventing damage to the support past of the rotator. This, in turn, creates a safe working environment with the machine.

ball bearings

What is the Classification of Bearings?

Bearings are components practically present in all mechanical pieces of equipment. However, they exist in various forms and shapes. Each bearing supports a specific type of movement or motion. The following are the various classifications of bearings and their examples:

Classification Based on the Type of Friction or Contact

  • Rolling contact bearings: It is also known as simply ball bearings or anti-friction bearings. Here, the rollers or spherical balls are put in between the surfaces in motion. They give room for more radial loads.
  • Sliding contact bearings: These are also known as journal bearings or sleeve bearings. The moving element or the shaft surface slides the bush, leading to wear and friction. These two surfaces are then separated by a film of lubricating oil to reduce the friction.

Classification Based on the Direction and Type of Load

  • Radial bearings: These bearings support radial loads located perpendicularly to the shaft axis or motion of the moving element. It is a subtype of ball bearings that operates by placing lubricated steel balls between two deep grooved rings.
  • Thrust or collar bearings: This mechanical bearing is also known as axial bearings. They support the load that acts along the motion of the moving element.

Types of Bearings and Their Unique Features

Bearings are of several types, with each having its own applications, and features that help them execute these applications. The following are the various types of bearings and their features:

Ball Bearing

It is a type of bearing made of spherical parts, such as a rotating shaft and fixed housing cage. These mechanical assemblies are joined together with fasteners, such as nails, rivet types, bolts, screws, and machining threads. The aim is to reduce the friction between them.

Ball bearing is used in several office equipment and industrial machines. They are a type of mechanical device best for frictionless and smooth operations. Ball bearings also support rotatory motion in applications and reduce noise.

This bearing provides good mechanical stability for machines that handle heavy radial and dynamic loads. Ball bearing also consists of four main parts of the common ball bearing family, which are:

  • The cage
  • The shield
  • Two rings (Inner and Outer ring)
  • The steel balls

Thrust Bearing

Thrust bearing is the best type of bearing used to support axial and thrust loads applied to a shaft. These bearings rotate along the parts of the machine while using balls to support the machine. They glide along the thrust bearings when the moving parts of the machines rotate.

These bearings are applied in several sectors and applications such as transportation, automotive, industrial machinery, and medical devices. Thrust bearings are highly reliable, available, and can withstand heavy loads.

FootStep Bearing

Footstep bearings or pivot bearings are one of the most common types of bearings because they support the lower end of vertical shafts. It helps to support shafts that move in axial thrust and are placed vertically. The footstep bearing consists of the following parts:

  • The body
  • Bearing disc
  • Bush
  • Locking pin

A major benefit of this type of bearing is that it is easy to maintain and dismantle. It has a simple and compact design for assembly which makes it best to use in shafts of steam turbines. Footstep bearing is also used in marine applications such as shafts with less load and speed.

Rolling Contact or Anti-Friction Bearing

A rolling contact bearing has low friction characteristics. They are popularly used for thrust load and radial load simultaneously. It is also designed to be self-aligning and they offer little resistance to movement. The most common types of rolling contact bearings are:

  • Cylindrical bearing
  • Ball bearing
  • Spherical bearing
  • Tapered roller bearings

This type of bearing is often applied in the following:

  • Medical pieces of equipment
  • Aviation cargo systems
  • Solar panels
  • Engines
  • Wind turbines
  • Powerhouses

Plain Bearing

Plain bearings are responsible for preventing wear and tear of the machine at support points. They are the simplest types of bearings that operate based on the principle of sliding friction without rolling elements. Since they have no moving parts, they tend to reduce noise when working. These bearing types are efficient, smooth, and good for heavy loads.

These bearings also accommodate multi-dimensional misalignments and movements. This feature makes it ideal for dynamic and static loads. Plain bearings are used in linear or rotary applications, construction, marine, and automotive industries.

Linear Bearing

Here, the bearing supports the load at its single-axis linear movement. Linear bearings are fluid-film mechanical devices that reduce friction in motion systems that act along a curved or straight pathway. They have high precision rates, which enable a precise straight motion. Its superior design enables it to accommodate a significant load capacity.

Linear bearing is also self-lubricating and efficient because it operates at a high speed while reducing energy loss. It is applicable in 3D printers, sliding doors, and automation settings.

Fluid Bearing

Fluid bearing enables smooth movement between two materials. It is a fluid-bearing surface that is vital in rotary machines. Fluid bearing uses fluid to reduce friction between surfaces. This type of bearing adapts easily to moderate misalignment and enables easy removal of calories by fluid. It is often seen in machines that work with heavy loads at higher speeds, such as marine or propeller shafts and hydroelectric plants. They are classified into:

  • Hydrostatic bearings
  • Hydrodynamic bearings

Jewel Bearing

Jewel bearings are mechanical parts made from gems such as sapphires and rubies, which are hard substances. It has a low coefficient of friction; hence, they do not wear down easily. Their hardness enables them to exhibit high resistance qualities; however, they may be at risk of fracturing due to shocks (radial or axial). This type of bearing is often applicable in clocks, gauges, indicators, and gyros.

Examples and Applications of Bearings

Some examples and applications of bearing are:

  • Ball bearings: In the medical industry, this bearing is used in several pieces of equipment or technology. Here, they are vital components in making micro-blood pumps, respirators, and analysis equipment.
  • Plain bearings: They are often used in the marine industry to rotate and reciprocate machines transmitting loads through the engine structure. It helps in the marine propulsion systems and the transfer of power.
  • Cylindrical roller bearings: This type of bearing is common in the aerospace industry. They are often found in the pumps, engines, and engine gearboxes. It is used in this high-speed application to reduce friction and handle heavy axial loads.

How to Choose the Right Types of Bearing for Your Needs?

Your application will determine what type of bearing it needs. When choosing a bearing to suit your needs, consider the following factors:

Bearing Load

All bearing types have designs that support either a radial or axial load, and some can support both. The axial load is the measurement of the forces acting parallel with the shaft while in radial, they are a right angle to the shaft. When choosing your bearing, consider its load capacity because it determines the right type of bearing you need.

Speed of Rotation

Bearings all have designs that enable them to operate at a certain speed range. This is because not all bearings can withstand high speeds. Look out for bearings with a cage, such as needle bearings, as they can withstand high speeds. However, check their load capacity as some of these bearings with a cage may not be able to withstand heavy loads.


Fluctuating temperature conditions will affect the parts of a rotating system, including bearing components. For example, in a lathe, the circular motion in which the spindle moves, helping to generate energy for whatever type of motion is needed would also create additional heat. Bearings must respond well to this heat from other rotating parts at varying temperatures because they are also sources of heat in a system.

Bearing Longevity and Rigidity

Take note of the rigidity of the bearing before making your choice. You can increase the rigidity of some bearings by applying the bearing’s preload system. A major benefit of this preload is that it helps to improve the bearing life.

Bearing Lubrication and Sealing

Lubrication helps to prevent overheating, abrasion, and friction in machines because it creates a film of oil. Bad lubrication is one of the major reasons for bearing failure. The sealing system influences the lasting operation of the bearing. A sealed system helps to keep contaminants out of the bearing, thereby preventing bearing failure.


Bearings are a mechanical element that helps to constrain relative motion and reduce friction between moving parts in a machine. It helps to support the rotating shaft of a machine to enable smooth movement. All bearing types have designs that enable them to work at a certain efficiency. When choosing a bearing for your machine, it is vital to check its load capacity, rotation speed, and temperature.


How Do I Choose the Best Bearing Type?

There are several factors to consider when choosing the best type of bearing. Ensure to check the load capacity, temperature, rigidity, and rotation speed.

Can I Refurbish My Bearing?

Yes, you can refurbish your bearing. However, it depends on a range of factors. These factors include the maintenance cycles, the environmental influences on the bear, and its accumulated wear.

What is the Cheapest and Simplest Type of Bearing?

The cheapest and simplest type of bearing is plain bearings. This is because it has no moving parts, and it comprises only the bearing and the surface it slides on.

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