Everything from small shopping carts to large energy facilities is often dependent on bearings. Bearings are critical elements in many mechanical systems. They are available in various shapes and sizes. In other words, they allow certain actions and restrict others. For instance, you can think about a sliding door. It cannot be lifted and removed as would a standard wheel. There is only one opening to this door and it is through the sliding kind. Bearing controls its movement to this sliding movement.
What Is the Primary Function of Bearings
Bearing is an essential part of most machines. They help in minimizing wear and tear between moving parts. This results in efficiency since fewer problems exist that hinder the implementation of procedures. They assist in stabilizing the body during movement. In this way, they increase efficiency by minimizing energy loss. Bearing extends the life span of the equipment. They ensure the parts are accurately aligned. The bearing can be classified into various categories depending on the type of use it will be subjected to. In general, bearings are indispensable components of mechanical systems.
Common Bearing Materials
The common bearing materials include metals, ceramics, and plastics:
- Steel
- Stainless Steel
- Bronze
- Plastic (e.g., nylon, PTFE)
- Ceramic (e.g., silicon nitride)
- Graphite
- Copper
- Aluminum
Types of Bearings Based On Rolling Elements & Operation
Let’s brief out some common types of bearings employed for their diverse benefits.
Type 1: Ball Bearings
Deep Groove Ball Bearings
Deep Groove Ball Bearings
Features of Deep Groove Ball Bearings:
- They have a simple design and are comparatively affordable.
- They have low friction and can work at high speeds.
- These bearings are identical for radial, and axial loads. Moreover, can accommodate heavy loads to reduce friction.
- While the larger versions feature stamped steel cages, they are replaced by solid metal cages. Last but not least, they are easy to maintain and known to have an extremely long lifespan.
- They provide some degree of alignment and are available in different sizes and formats.
Type 2. Roller Bearings
1. Cylindrical Roller Bearings
Cylindrical Roller Bearings
Features of Cylindrical Roller Bearings:
- These bearings have linear contact. So, they can accommodate radial loads.
- They have a low coefficient of friction, ideal for high-speed use.
- Three are typically 2 variants of cylindrical bearings: N-type and NU-type are designed for axial movement and adjust for thermal expansion.
- Cylindrical bearings help accurately installations to avoid stress concentrations.
- Their inner and outer rings are also detachable to allow easy fixing and removal.
2. Tapered Roller Bearings
Tapered Roller Bearings
Features of Tapered Roller Bearings:
- Tapered bearing, as the name implies, enables a tapered design for carrying both radial and axial loads in a single shaft.
- Their design ensures contact points between the roller and the raceway are in the correct orientation for proper running.
- They can also be a single-row, double-row, or four rows depending on the amount of rollers present in them.
- A new design improves the strength and durability of the rollers, which are longer and have better geometries.
- The spherical and conical contact of the roller bearings increases lubrication capacity.
Type 3. Thrust Bearings
1. Thrust Ball Bearings
Thrust Ball Bearings
Features of Thrust Ball Bearings:
- These bearings with a 90° contact angle are suitable to carry only axial loads.
- They work at low rpm; there is a tendency for centrifugal force to induce wear.
- Thrust bearings come in two types: Way and Two-way bearings. The one-way bearings are vital for single-direction loads. Contrarily, the two-way bearings are dual-direction loads.
- Spherical seat rings enable adjustment to correct installation inaccuracies.
2. Thrust Roller Bearings
Thrust Roller Bearing
Features of Thrust Roller Bearings:
- These bearings support unidirectional axial loads. Also, they can sustain minor shocks, so, usually helpful in specialized applications.
- Thrust roller bearings offer high stiffness, small size, and good capability of carrying axial loads.
- They are specifically optimal for slow speed where thrust ball bearings are not applicable.
- A significant amount of care has to be taken during the installation process to make sure, panels are not tilted.
Type 4. Needle Bearings
Needle Roller Bearing
Features of Needle Roller Bearings:
- These bearings entail a small radial sectional thickness. But keep a high radial load-carrying capacity.
- They are Light and compact in weight, so ultimately reduce overall equipment weight.
- Many times there are no inner or outer rings and thus they need to be machined.
- They also possess high friction coefficients which renders them incapable of operating at high velocities.
Type 5. Plain Bearings
Plain Bearing
Features of Plain Bearings:
- It is worth noting that they function effectively, without noise.
- In liquid lubrication, the two surfaces are kept apart and therefore there is little friction or wear.
- The oil film is beneficial for vibration absorption but has a higher starting friction than the steel film.
Type 6. Magnetic Bearings
Magnetic Bearings
Features of Magnetic Bearings:
- Magnetic bearings have no mechanical contact. Therefore, the bearing can support high speeds.
- They give low wear, energy consumption, and noise levels, and do not require lubrication.
- Typically, used in machining, aerospace, and vacuum technologies, they are a new generation of bearings.
Considerations For Choosing Different Types of Bearings
1. Load Considerations
- Radial bearings should be used for predominantly radial loads. These are typical loads, perpendicular to the shaft.
- For loads acting along the shaft, use axial bearings commonly, referred to as thrust bearings.
- Roller bearings are used for heavy loads.
- When both radial and axial loads are to be supported, if the combined load is small, deep groove or angular contact ball bearings should be used. For heavy loads select tapered roller bearings.
- Plain bearings can be used for low-speed, high-load conditions.
2. Rotational Speed
- High-speed applications require deep groove ball bearings, angular contact bearings, and cylindrical roller bearings.
- A tapered roller bearing is preferable for lower-speed applications.
- Thrust ball bearings have a relatively low limiting speed and therefore should be used in slow-running applications only.
- In general, bearings of the same type, but of smaller dimensions, can accommodate higher speeds. Make sure the operating speed is kept below the maximum allowable limit.
3. Accuracy Requirements
- For precision machinery, for example, machine tool spindles, high accuracy bearings deep groove ball bearings, angular contact ball bearings, and tapered roller bearings are used.
- They include deep groove balls and cylindrical roller bearings, which are suitable for applications requiring high rotational accuracy.
- In most machinery, standard tolerance bearings are normally adequate.
4. Rigidity Factors
- Usually, rolling bearings have little elastic deformation, but rigidity is essential in some cases, such as machine tool spindles. In such circumstances, cylindrical and tapered roller bearings are usually advisable.
- They can also be preloaded to increase their stiffness. For instance, it is possible to preload angular contact and tapered roller bearings to minimize shaft vibrations and increase support stiffness.
5. Additional Considerations
- In restricted radial dimensions, use needle roller bearings or needle roller and cage assemblies.
- If the problem is vibration and noise, select low-noise-deep groove ball bearings.
- Where high rotational accuracy and speed are necessary, then use bearings that have designs beyond the standard.
Summary
In summary, the choice of the bearing depends on rolling movement and operations. In this article, we have comprehended the information about different types and bearings and their respective purpose. If you want to learn more about bearings, contact us now! Topsbest-Precision has the vision of providing the most optimal solutions for bearing and fastener products for your specific project requirements.