A ball bearing is a bearing that relies on balls to keep the bearing races separate. The function of a ball bearing is to reduce rotational friction while supporting radial and axial stresses. Ball bearings have been around for hundreds of years and have been used in a variety of applications, intended to withstand axial and radial stresses in everything from hard drives to skateboards. On the other hand, ball bearings are also often used in situations with lower pressures.
The load is transferred from the outer stroke of the ball to the inner stroke. Everything can spin smoothly because the spherical shape of the ball makes little contact with the inner and outer lanes. However, if the bearing is not used properly, it can become an impediment. If the bearing is overloaded, the balls can deform and damage the bearing due to the narrow contact area that carries the load.
Ball bearings are typically made from chrome steel or stainless steel. Surprisingly, glass or plastic beads also have use cases in some consumer applications. They are also available in various sizes, from miniature bearings for hand tools to large bearings for industrial machines. Their load capacity and reliability generally evaluate ball bearing units.
When choosing a ball bearing, it is essential to consider the operating conditions and the level of reliability required.
Two types of ball bearings
Single row ball bearing and double row ball bearing are the two main types of ball bearings. Single row ball bearings have one row of balls and are suitable for applications where radial and axial loads are relatively low. Double row ball bearings have two rows and are used in applications where greater loads are expected or where higher levels of reliability are required.
Single row ball bearings
1. Single row angular contact ball bearings
(Source: SKF)
These bearings can support axial loads in one direction only, usually against a second bearing with non-separable rings. They include a large number of spheres to give them a relatively high load capacity.
Advantages of single row angular contact ball bearings:
- High load capacity
- Good flow properties
- Easy mounting of universally compatible bearings
2. Single row deep groove ball bearings
(Source: SKF)
The most common form of ball bearing is a single row deep groove ball bearing. Its use is quite common. The inner and outer ring race grooves contain circular arcs slightly larger than the radius of the balls. In addition to radial loads, axial loads can be applied in both directions. They are suitable for applications that require high speeds and minimal power losses due to their low torque.
Applications of single row ball bearings:
- Medical diagnostic equipment, flowmeters and anemometers
- Optical encoders, electric motors and dental hand tools
- Industry of hand tools, industrial blowers and thermal cameras
Double row ball bearings
1. Double row angular contact ball bearings
(Source: SKF)
They can accommodate radial and axial loads in both directions and tilting moments, with a design comparable to two single-row bearings placed against each other. Two individual bearings usually take up a lot of axial space.
Advantages of a double row angular contact ball bearing:
- Less axial clearance allows radial and axial loads to be accommodated in both directions.
- Bearing arrangement with high tension
- Allows moments of reversals
Main differences between double row and single row ball bearings
Single row ball bearings are the most common type of ball bearings. This bearing has a row of rolling parts, with a simplistic construction. They are non-separable, suitable for high speeds and durable in operation. They can withstand radial and axial loads.
Double-row ball bearings are more robust than single-row ball bearings and can withstand higher loads. This type of bearing can support radial and axial loads in both directions. It can maintain the axial movement of the shaft and housing within the axial clearance of the bearing. However, they are also more complex in design and require more precise manufacturing tolerances.
Conclusion
Single row and double row ball bearings are widely used in various applications. Single row is commonly used in light-duty applications while double row is more suitable for heavy-duty applications. Ball bearings are essential components in many types of machines and equipment.
To ensure the correct functioning of the bearings. All ball bearings must withstand a minimum load, especially at high speeds or strong accelerations or when the direction of the load changes quickly. The inertial force of the ball and cage and the friction in the lubricant will negatively affect the bearing bearing and a sliding motion may occur between the ball and race, potentially damaging the bearing.
