Bearing serves as a fundamental component in machinery and finds extensive application in various industries. It also functions as an essential support element for diverse machines. As such, the realm of bearings encompasses a variety of types, each bearing type possessing distinct characteristics.
In this article, we will delve into the different classifications of bearings, their uses, materials, and more.
What is Mechanical Bearing?
A bearing is a mechanical component that supports and facilitates the rotational or linear movement of machinery parts by minimizing friction. It serves to reduce the resistance between moving parts, thereby enabling smooth and controlled motion. Additionally, mechanical bearings are components used in machinery to facilitate smooth and controlled motion by reducing friction between moving parts. Mechanical bearings come in various types, such as ball bearings, roller bearings, plain bearings, and sleeve bearings, each designed to suit specific applications and load requirements. Overall, bearings play a vital role in various mechanical systems and industrial applications, providing support for shafts, axles, and other rotating or linear components within machinery.
Types of Bearings
Bearings can be mainly divided into two common types: ball bearings and roller bearings. Ball Bearing has spherical balls sandwiched between two rings, including the inner and outer rings. Roller bearing, on the other hand, has cylindrical or tapered rolling elements instead of balls. The shape of the rolling elements varies based on the type of roller bearing, such as cylindrical, tapered, spherical, and more.
Additionally, we can categorize ball bearings into the following types.
- Deep-Groove Ball Bearings:
Deep-groove ball bearing is characterized by its ability to accommodate both radial and axial loads. This bearing feature deep raceway grooves in both the inner and outer rings, enabling them to support high radial loads, as well as moderate axial loads in both directions.
Moreover, it commonly finds in a wide range of applications, including automotive, industrial machinery, agricultural equipment, and precision instruments, due to their versatility and capability to operate at high speeds. - Self-Aligning Ball Bearings:
Self-aligning ball bearings are specifically designed to accommodate misalignment between the shaft and the housing. These bearings involve two rows of balls running on a common spherical outer raceway, allowing them to self-align.
Furthermore, this self-aligning capability helps compensate for shaft deflections and alignment errors that may occur during operation, reducing the risk of premature bearing failure. Their unique design provides ease of installation and maintenance and allows access to various applications, such as conveyor systems, agricultural machinery, and industrial equipment. - Angular Contact Ball Bearings Angular contact ball bearings are applied to support combined radial and axial loads in a specific direction. These bearings have raceways in the inner and outer rings arranged at an angle, usually 15°, 25°, 30°, or 40°, to the bearing axis. This angular contact design allows the bearings to withstand higher axial loads than deep-groove ball bearings. They are suitable for applications where both radial and axial forces are present, such as in machine tools, pumps, and gearboxes. In addition, these bearings come in single-row and double-row configurations, offering flexibility and high precision in demanding industrial environments.
- Thrust Ball Bearings
Thrust ball bearings are designed to accommodate axial loads along a single direction. These bearings with a contact angle of 90° consist of a shaft washer, a housing washer, and a ball and cage assembly. The raceway grooves in the washers allow the balls to move freely and support thrust forces in one direction.
What’s more, thrust ball bearings are commonly utilized in applications where axial loads need to be supported, such as in automotive transmissions, steering systems, and machine tool spindles. Their design enables efficient transmission of high axial loads while maintaining relatively low friction.
Simultaneously, roller bearings also fall into the following classifications:
- Spherical Roller Bearings
These bearings feature a design with barrel-shaped rollers, enabling them to withstand heavy radial. Additionally, they have the capability to adjust to misalignment, owing to their internal design.
On the other hand, spherical roller bearings are often employed in applications where high radial loads, misalignment, and heavy-duty performance are factors, such as in mining and construction equipment, vibrating screens, and paper mill machinery. Their ability to operate in demanding conditions and adjust to shaft deflections make them valuable components. - Cylindrical Roller Bearings
Cylindrical roller bearings are distinguished by their cylindrical rollers, enabling them to support heavy radial loads and deliver excellent performance in applications requiring high radial rigidity. They also possess the ability to support heavy radial loads and accommodate shaft misalignment. Therefore, these bearings are commonly used in machinery, including rolling mills, gear drives, and more. - Tapered Roller Bearings
Tapered roller bearings feature a design with tapered inner and outer ring raceways and tapered rollers. This design allows these bearings to accommodate combined radial and axial loads. They are commonly found in automotive and industrial applications, such as in wheel bearings and transmissions. Meanwhile, their capability to support thrust loads and provide precise alignment makes them invaluable in various mechanical systems. - Needle Roller Bearings
Needle roller bearings involve long, thin cylindrical rollers, with the ratio of diameter to length ranging from 1:3 to 1:10. They offer a compact design, high load-carrying capacity, and precise motion control in actual usage. Additionally, they are found in various applications such as industrial gearboxes, medical equipment, and more. - Thrust Roller Bearings
They are similar to thrust ball bearings but employ cylindrical rollers that are oriented parallel to the shaft. They are capable of withstanding only unidirectional axial loads and minor shocks. As such, they are used in various industrial applications, such as marine propulsion systems, crane hooks, and more.
In addition to ball bearings and roller bearings, there are also other specific types of bearings.
- Plain Bearings
Plain bearings consist of a surface with no rolling elements, also known as bushings or sleeve bearings. Instead of balls or rollers, plain bearings rely on a sliding action between the bearing surface and the shaft to support and guide the moving parts. They are commonly used in various applications, such as in automotive components, machinery, and industrial equipment. Moreover, they are cost-effective and reliable solutions for providing support and reducing friction in rotary. - Magnetic Bearings
Magnetic bearings use magnetic fields to levitate and support rotating shafts without physical contact. They typically consist of electromagnets that generate magnetic fields to repel the shaft and keep it in a stable position.
Magnetic bearings offer significant advantages over traditional mechanical bearings, such as reduced friction, no lubrication requirements, high-speed capabilities, and minimal maintenance. They are commonly utilized in high-speed rotating machinery, such as gas turbines, centrifugal compressors, and high-speed motors.
Applications of bearings
- Automotive Industry: For wheels, engines, transmissions, and different mechanical components to facilitate smooth and efficient movement.
- Industrial Machinery: Like conveyor systems, pumps, compressors, and processing equipment.
- Aerospace and Aviation: Such as landing gear, engines, and control mechanisms.
- Construction Equipment: Like cranes, excavators, and bulldozers.
- Railway and Transportation: For smooth movement of train wheels, axles, and various components.
- Energy Sector: Such as turbines, generators, and wind turbines.
- Marine Industry: In ship propulsion systems, steering mechanisms, and auxiliary machinery.
- Medical Devices: Like MRI machines, surgical tools, and prosthetic devices.
To Choose Different Types Of Bearings
- Load Capacity: Determine the magnitude and type of loads the bearing will need to support, such as radial, axial, or combined, to choose a bearing with the appropriate load capacity.
- Speed: Consider the operating speed of the application to select bearings that can withstand the rotational speed without compromising performance.
- Precision: Depending on the application requirements, choose bearings to ensure accurate operation and minimal clearance.
- Lubrication: Evaluate the lubrication conditions and maintenance requirements of the application. This evaluation will help in choosing between different bearing types, such as grease-lubricated, oil-lubricated, or self-lubricating bearings.
- Temperature and Environment: Take into account the operating temperature range and environmental conditions (such as moisture or contaminants) to select bearings that can withstand these conditions.
- Others： Other considerations, such as mounting and installation, space constraints, cost, and availability, also need to be taken into account when choosing the right type of bearings.
Types of Bearing Mechanical Materials
| Bearing Material | Characteristics | Common Types |
| Steel | Outstanding hardness, strength, wear resistance | AISI 52100 |
| Ceramics | High temperature resistance, corrosion resistance, exceptional wear characteristics | Silicon Nitride (Si3N4), Zirconia (ZrO2) |
| Stainless Steel | Corrosion resistance | 440 stainless steel, 316 stainless steel |
| Plastics | Low friction, chemical resistance, self-lubricating | Nylon (PA), Polytetrafluoroethylene (PTFE) |
| Bronze and Brass Alloys | Good wear resistance, good corrosion resistance | Phosphor bronze, Aluminum bronze |
| Composite Materials | Self-lubrication, high load capacity, vibration damping | Metal matrix with embedded solid lubricants, Fiber-reinforced polymers |
Conclusion
In summary, selecting the right bearing involves considering various factors. evaluating the characteristics of different bearing types, we aim to address your inquiries effectively. Runsom Precision is dedicated to offering comprehensive bearing and fastener solutions tailored to your project needs, providing a convenient one-stop service experience.
Should you still have any confusion regarding bearings and which one to choose, please feel free to contact us and ask for an instant quote.