1、 Clarify the requirements for mechanical applications
Understand the function and structure of machinery
The primary task before choosing a ball bearing is to have a deep understanding of the mechanical function and structure. This includes determining the specific role that ball bearings play in machinery, such as supporting rotating components, transmitting power, or bearing loads in specific directions. At the same time, analyze the overall structure of the machinery, understand the installation position of ball bearings and their interaction with surrounding components. For example, in automotive engines, ball bearings are used to support crankshafts and connecting rods, which need to be able to withstand high speeds and large radial and axial loads. Therefore, when choosing ball bearings, priority should be given to their material strength, lubrication method, and durability.
Determine the usage conditions of ball bearings
The usage conditions of ball bearings are crucial for their selection. This includes factors such as load size and direction, rotational speed, vibration and impact, bearing temperature, and surrounding atmosphere. The size and direction of the load determine the load-bearing capacity and type selection of ball bearings. For example, deep groove ball bearings are suitable for radial loads, while angular contact ball bearings are suitable for simultaneously bearing radial and axial loads. The rotational speed determines the maximum speed and lubrication method of ball bearings, and high-speed running bearings need to choose types with low friction and high heat dissipation performance. Vibration and impact require higher durability of bearings, and it is necessary to choose bearings with strong anti vibration performance. The temperature of the bearing and the ambient atmosphere affect the lubrication and sealing design of the bearing. For example, high-temperature environments require the selection of high-temperature resistant lubricating grease or oil.

2、 Choose the appropriate type of ball bearing
Deep groove ball bearing
Deep groove ball bearings are one of the most common types of ball bearings, with advantages such as simple structure, low friction coefficient, high ultimate speed, and high precision. They are mainly used to withstand radial loads, but can also withstand certain axial loads. Deep groove ball bearings are widely used in machinery such as automobiles, tractors, machine tools, and electric motors, such as wheel hub bearings for automobiles and spindle bearings for machine tools. When selecting deep groove ball bearings, factors such as inner diameter, outer diameter, width, accuracy level, and lubrication method should be considered to ensure that the bearings can meet the operational requirements of the machinery.
Angular contact ball bearing
Angular contact ball bearings have the ability to simultaneously withstand radial and axial loads, and the larger the contact angle, the greater the axial load capacity. The common contact angles are 15 °, 25 °, 30 °, and 40 °, and users can choose the appropriate contact angle according to their actual needs. Angular contact ball bearings need to be installed in pairs to balance the axial force generated. They are widely used in machinery such as machine tool spindles and high-frequency motors that require simultaneous radial and axial loads. When selecting angular contact ball bearings, in addition to considering their inner diameter, outer diameter, width, and accuracy level, attention should also be paid to their matching and installation methods to ensure that the bearings can be correctly installed and operate stably.
Tapered roller bearing
Conical roller bearings mainly bear radial loads and can also withstand certain axial loads. The rollers are guided by the large retaining edge of the inner ring, and are designed so that the vertices of the conical surfaces of the inner ring raceway surface, outer ring raceway surface, and roller rolling surface intersect at a point on the bearing centerline. This design enables tapered roller bearings to have high load-bearing capacity, rigidity, and anti vibration performance. They are widely used in gear reducers for construction machinery, large agricultural machinery, and railway vehicles. When choosing tapered roller bearings, attention should be paid to factors such as inner diameter, outer diameter, width, taper ratio, accuracy level, and lubrication method to ensure that the bearings can meet the operational requirements of the machinery.
Thrust ball bearing
Thrust ball bearings are used for bearing the main axial load and radial combined load, but the radial load shall not exceed 55% of the axial load. They have a low coefficient of friction, high speed, and have the ability to adjust center. Thrust ball bearings are widely used in machinery such as hydroelectric generators and lifting hooks. When selecting thrust ball bearings, attention should be paid to factors such as their inner diameter, outer diameter, height, accuracy level, and lubrication method. Meanwhile, since thrust ball bearings mainly bear axial loads, their axial load-bearing capacity should also be considered when selecting to meet mechanical requirements.
Other types of ball bearings
In addition to the common types of ball bearings mentioned above, there are also some special types of ball bearings, such as self-aligning ball bearings, automatic self-aligning roller bearings, etc. These bearings have automatic centering performance, which can automatically adjust the axis misalignment caused by the deflection or non concentricity of the shaft or bearing seat. They are widely used in paper making machinery, reduction gears, railway vehicle axles, and other machinery that require complex loads and misaligned axes. When selecting these special types of ball bearings, attention should be paid to factors such as their inner diameter, outer diameter, width, accuracy level, centering ability, and lubrication method to ensure that the bearings can meet the operational requirements of the machinery.

3、 Consider other factors
Bearings tolerance 
Bearing tolerance refers to the dimensional accuracy and rotational accuracy of the inner and outer rings, rolling elements, and cage of the bearing. According to ISO and JIS standards, bearing tolerances are divided into multiple grades, and users can choose the appropriate tolerance grade according to their actual needs. For machinery that requires high precision and high-speed operation, it is recommended to use bearings with a precision level of 5 or higher. When selecting bearing tolerances, the operating conditions of the machinery and the type of bearing should also be considered. For example, for bearings that operate at high speeds, a lower tolerance level should be selected to reduce friction and heat generation; For bearings that can withstand heavy loads, a higher tolerance level should be selected to ensure their load-bearing capacity.
rigidity
Rigidity refers to the ability of a bearing to resist deformation when subjected to load. When the rolling elements and raceway contact surfaces of a bearing are compressed, elastic deformation occurs. Roller bearings produce less elastic deformation than ball bearings, so roller bearings should be given priority in machinery that requires high rigidity. However, in some cases, such as the machinery that needs to bear complex loads and the axis is not aligned, self-aligning ball bearings and other bearings with automatic self-aligning performance may be more suitable. When selecting bearings, factors such as mechanical operating conditions, bearing types, and rigidity requirements should be comprehensively considered.
Installation and disassembly
The installation and disassembly of bearings are important steps in mechanical maintenance and upkeep. When selecting bearings, consideration should be given to whether their installation and disassembly methods are convenient. For example, bearings that can be installed separately on the inner and outer rings (such as cylindrical bearings, needle roller bearings, and tapered bearings) are very suitable for situations that require frequent disassembly and installation. In addition, attention should be paid to whether the sealing design and lubrication method of the bearing are easy to install and disassemble. For example, bearings with sealing rings can simplify the installation process and reduce the risk of leakage; Bearings lubricated with grease can be directly filled with grease after installation without the need for an additional lubrication system.
Lubrication method
Lubrication is one of the key factors for the normal operation of bearings. It is crucial to choose the appropriate lubrication method based on the operating conditions of the machinery and the type of bearings. For situations with extremely high rotational speeds, priority should be given to using oil lubrication to provide sufficient cooling and lubrication effects; For situations with extremely low temperatures or requiring sealing, grease lubrication can be considered to reduce leakage and wear. When choosing a lubrication method, factors such as the type, amount, and replacement cycle of the lubricant should also be considered. For example, for bearings in high-temperature environments or corrosive atmospheres, lubricants that are resistant to high temperatures or corrosion should be selected; For bearings that require long-term operation, lubricants with longer service life should be selected.

Bearing lifespan
The bearing life refers to the time or number of revolutions that a bearing can operate normally under specific conditions. When selecting bearings, the lifespan should be calculated based on the mechanical operating conditions and bearing type. This includes considering factors such as bearing capacity, speed, temperature, lubrication method, and surrounding environment. The calculated bearing life should match the expected service life of the machinery. In addition, attention should be paid to the fatigue life and ultimate speed parameters of the bearings to ensure that they can meet the operational requirements of the machinery. When choosing bearings, priority can be given to bearing types with high fatigue life and ultimate speed, such as cylindrical roller bearings with convexity, reinforced tapered roller bearings, etc., to improve mechanical performance and service life.