Bearings are important components in mechanical equipment. Its main function is to support the mechanical rotating body to reduce the friction coefficient of the mechanical load during the transmission process of the equipment.
Bearings are divided into radial bearings and thrust bearings according to different load-carrying directions or nominal contact angles.

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According to the type of rolling elements, they are divided into: ball bearings and roller bearings.
According to whether they can be aligned, they are divided into: self-aligning bearings and non-aligning bearings (rigid bearings).
According to the number of rows of rolling elements, they are divided into: single-row bearings, double-row bearings, and multi-row bearings.
According to whether the components can be separated, they are divided into: separable bearings and non-separable bearings.
There are also classifications based on structural shape and size.
This article mainly shares the characteristics, differences and corresponding uses of 14 common bearings.

1.
There is a contact angle between the angular contact ball bearing ring and the ball. The standard contact angles are 15°, 30° and 40°. The larger the contact angle, the greater the axial load capacity. The smaller the contact angle, the more beneficial it is. Rotating at high speed, single-row bearings can bear radial load and one-way axial load. Structurally, two single-row angular contact ball bearings combined on the back share the inner ring and outer ring and can bear radial load and bidirectional axial load. Main uses: single row: machine tool spindle, high-frequency motor, gas turbine, centrifugal separator, small car front wheel, differential pinion shaft. Double row: oil pumps, Roots blowers, air compressors, various transmissions, fuel injection pumps, printing machinery.

2. Aligning ball bearings
have double rows of steel balls, and the outer ring raceway is an inner spherical type, so it can automatically adjust the axis misalignment caused by deflection or non-concentricity of the shaft or shell. Bearings with tapered holes can be easily adjusted by using fasteners. Installed on the shaft, it mainly bears radial load.

Main uses: woodworking machinery, textile machinery drive shafts, vertical seated self-aligning bearings. 3. Spherical roller bearings This type of bearing is equipped with spherical rollers between the spherical raceway outer ring and the double raceway inner ring. According to the different internal structures, it is divided into four types: R, RH, RHA and SR. Since the outer ring The arc center of the raceway is consistent with the bearing center and has self-aligning performance. Therefore, it can automatically adjust the axis center misalignment caused by deflection or non-concentricity of the shaft or housing, and can withstand radial load and bidirectional axial load.

Main uses: papermaking machinery, reduction gears, railway vehicle axles, rolling mill gearbox seats, rolling mill rollers, crushers, vibrating screens, printing machinery, woodworking machinery, various industrial reducers, vertical seated spherical bearings . 4. Thrust spherical roller bearings The spherical rollers in this type of bearing are arranged obliquely. Since the raceway surface of the seat ring is spherical and has self-aligning performance, it can allow the shaft to tilt to some extent. The axial load capacity is very large. When bearing the shaft In addition to the radial load, it can also bear some radial loads. Oil lubrication is generally used when in use.

Main uses: hydraulic generators, vertical motors, propeller shafts for ships, reducers for rolling screws in rolling mills, tower cranes, coal mills, extruders, and forming machines. 5. Tapered roller bearings This type of bearing is equipped with tapered rollers. The rollers are guided by the large ribs of the inner ring. The design makes the inner ring raceway surface, the outer ring raceway surface and the tapered surfaces of the roller rolling surfaces The vertex intersects at a point on the bearing centerline. Single-row bearings can bear radial loads and one-way axial loads, while double-row bearings can bear radial loads and two-way axial loads, and are suitable for bearing heavy loads and impact loads.

Main uses: Automobiles: front wheels, rear wheels, transmissions, differential pinion shafts. Machine tool spindles, construction machinery, large agricultural machinery, railway vehicle gear reduction devices, rolling mill roll necks and reduction devices. 6. Deep groove ball bearings Structurally, each ring of a deep groove ball bearing has a continuous groove raceway with a cross-section that is approximately one-third of the circumference of the ball. Deep groove ball bearings are mainly used to bear radial loads and can also bear certain axial loads. When the radial clearance of the bearing increases, it has the properties of an angular contact ball bearing and can withstand alternating axial loads in two directions. Compared with other types of bearings of the same size, this type of bearing has a small friction coefficient, a high limit speed, and high precision. It is the preferred bearing type for users when selecting.

Main uses: automobiles, tractors, machine tools, motors, water pumps, agricultural machinery, textile machinery, etc. 7. Thrust ball bearings are composed of a washer-shaped raceway ring with a raceway and a ball and cage assembly. The raceway ring that matches the shaft is called a shaft ring, and the raceway ring that matches the shell is called a seat ring. The two-way bearing matches the secret shaft of the middle ring. The one-way bearing can bear one-way axial load, and the two-way bearing can bear two-way axial load (neither can bear radial load).

Main uses: automobile steering pins, machine tool spindles. 8. Spherical roller thrust bearings Spherical roller thrust bearings are used to bear mainly axial loads, combined radial and axial loads, but the radial load shall not exceed 55% of the axial load. Compared with other thrust roller bearings, this kind of bearing has a lower friction coefficient, higher rotation speed, and has the ability to adjust. The rollers of the 29000 bearing are asymmetric spherical rollers, which can reduce the relative sliding between the rollers and the raceways during operation. The rollers are long and have a large diameter. They have a large number of rollers and a large load capacity. They are usually lubricated by oil. Grease lubrication can be used in some low-speed situations.

Main uses: hydraulic generators, crane hooks. 9. Cylindrical roller bearings The rollers of cylindrical roller bearings are usually guided by two ribs of a bearing ring. The cage roller and the guide ring form an assembly that can be separated from another bearing ring and is removable. Release bearing. This kind of bearing is more convenient to install and disassemble, especially when the interference fit between the inner and outer rings, the shaft and the shell is required. This type of bearing is generally only used to bear radial loads. Only single-row bearings with ribs on both the inner and outer rings can bear small steady axial loads or large intermittent axial loads.

Main uses: large motors, machine tool spindles, axle boxes, diesel engine crankshafts, automobiles, tractor transmissions, etc. 10. Four-point contact ball bearings can bear radial loads and bidirectional axial loads. A single bearing can replace the front-side or back-side combination angular contact ball bearings, and is suitable for bearing pure axial loads or synthetic loads with a large axial load component. , this type of bearing can form one of the contact angles when it bears axial load in any direction, so the ring and the ball are always in four-point contact on any contact line.

Main uses: aircraft jet engines, gas turbines. 11. Thrust cylindrical roller bearings are composed of washer-shaped raceway rings (shaft rings, seat rings), cylindrical rollers and cage components. The cylindrical roller adopts convex surface processing, so the pressure between the roller and the raceway surface is evenly distributed, and it can withstand one-way axial load. It has large axial load capacity and strong axial rigidity.

Main uses: oil drilling rigs, iron and steel making machinery. 12. Thrust needle roller bearings Separable bearings are composed of raceway rings, needle rollers and cage assemblies, and can be combined with stamped thin raceway rings or cut-processed thick raceway rings. Non-separable bearings are integral bearings composed of precision stamped raceway rings, needle rollers and cage assemblies. They can withstand unidirectional axial loads. This type of bearing takes up little space and is conducive to the compact design of machinery. Most of them Only the needle roller and cage assembly is used, and the mounting surface of the shaft and housing is used as the raceway surface.

Main uses: transmission devices for automobiles, cultivators, machine tools, etc. 13. Thrust tapered roller bearings This type of bearing is equipped with truncated cone-shaped rollers (the big end is spherical). The rollers are accurately guided by the raceway ring (shaft ring, seat ring) ribs. The design makes the shaft ring and seat ring The apex of each conical surface of the raceway surface and the roller rolling surface intersects at a point on the bearing center line. One-way bearings can bear one-way axial load, and two-way bearings can bear two-way axial load.

Main uses:
One-way: crane hook, oil drilling rig swivel.
Both directions: rolling mill roll neck.

14. Insert spherical ball bearing with seat.
Insert spherical ball bearing with seat is composed of an radial ball bearing with seals on both sides and a cast (or steel plate stamped) bearing seat. The internal structure of the outer spherical ball bearing is the same as that of the deep groove ball bearing, but the inner ring of this bearing is wider than the outer ring. The outer ring has a spherical outer surface, which can be automatically aligned with the concave spherical surface of the bearing seat.

Main uses: mining, metallurgy, agriculture, chemical industry, textile, printing and dyeing, conveying machinery, etc.