The characteristics of different bearings
The bearings are important components in mechanical equipments. Its main function is to support the mechanical rotating body to reduce the mechanical load friction coefficient of the equipment during transmission.
Bearings are divided into radial bearings and thrust bearings according to different load directions or nominal contact angles.
According to the types of rolling elements, they are divided into: ball bearings and roller bearings.
According to whether the bearing can be aligned, it can be divided into: self-aligning bearings and non-aligning bearings (rigid bearings).
According to the number of rows of rolling elements: single row bearings, double row bearings, multi-row bearings.
According to whether the parts can be separated, it can be divided into: separable bearings and non-separable bearings.
In addition, there are classifications according to structural shape and size.
Here are the characteristics, differences and corresponding uses of several common bearings.
1. Angular contact ball bearings
There is a contact angle between the rings and the ball. The standard contact angles are 15 °, 30 ° and 40 °. The larger the contact angle is, the greater the axial load capacity is. The lower the rotating speed is.
The main application:
Single row: machine tool spindle, high-frequency motor, gas turbine, centrifugal separator, small car front wheel, differential pinion shaft.
Double row: oil pump, Roots blower, air compressor, various transmissions, fuel injection pump, printing machinery.
2. Self-aligning ball bearings
Double rows of steel balls, the outer ring raceway is inner ball shape, so it can automatically adjust the shaft center error caused by the deflection of the shaft or the casing or out of center. The tapered hole bearing can be easily installed on the shaft by using fasteners, mainly Withstand radial load.
Main application: woodworking machinery, textile machinery drive shaft, vertical self-aligning bearing with seat.
3. Spherical roller bearings
This type of bearing is equipped with spherical rollers between the outer ring of the spherical raceway and the inner ring of the double raceway. According to the difference in internal structure, it is divided into four types: R, RH, RHA and SR. The bearing center is consistent and has the self-aligning performance, so it can automatically adjust the axial center error caused by the deflection of the shaft or casing or the non-centering, and can withstand radial load and bidirectional axial load.
Main application: papermaking machinery, reduction gears, railway vehicle axles, rolling mill gear box seats, rolling mill rollers, crushers, vibrating screens, printing machinery, woodworking machinery, various types of industrial reducers, vertical self-aligning spherical bearings.
4. Thrust spherical roller bearings
In this type of bearing, the spherical rollers are arranged diagonally. Since the raceway surface of the race is spherical and has self-aligning performance, it can allow some tilting of the shaft, and the axial load capacity is very large. Radial load, generally use oil lubrication.
Main application: hydroelectric generators, vertical motors, propeller shafts for ships, reducers for rolling screws of steel rolling mills, tower cranes, coal mills, extruders, forming machines.
5. Tapered roller bearings
This type of bearing is equipped with a round table-shaped roller. The roller is guided by the large rib of the inner ring. The design makes the vertex of each conical surface of the inner ring raceway surface, outer ring raceway surface and roller rolling surface intersect the bearing centerline On the point. Single-row bearings can bear radial load and one-way axial load, double-row bearings can bear radial load and two-way axial load, suitable for withstanding heavy load and impact load.
Main application: Automotive: front wheel, rear wheel, transmission, differential pinion shaft. Machine tool spindle, construction machinery, large agricultural machinery, railway vehicle gear reduction device, rolling mill roll neck and reduction device.
6. Deep groove ball bearings
Structurally, each ring of a deep groove ball bearing has a continuous groove raceway with a cross section of about one third of the equatorial 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 axial loads alternating in two directions. Compared with other types of bearings of the same size, this type of bearing has a small friction coefficient, high limit speed and high accuracy. It is the preferred bearing type when the user selects the type.
Main application: cars, tractors, machine tools, motors, water pumps, agricultural machinery, textile machinery.
7. Thrust ball bearings
It is composed of a washer-shaped raceway ring with a raceway and a ball and a cage assembly. The raceway ring matched with the shaft is called a shaft ring, and the raceway ring matched with a housing is called a seat ring. The two-way bearing fits the middle ring’s secret shaft, the one-way bearing can bear one-way axial load, and the two-way bearing can bear two-way axial load (both cannot bear radial load).
Main application: automotive steering pins, machine tool spindles.
8. Thrust roller bearings
Thrust roller bearings are used for shafts that are mainly subjected to axial loads. The combined meridional load, but the meridional load must not exceed 55% of the axial load. Compared with other thrust roller bearings, this type of bearing has a lower friction factor, a higher speed, and the ability to align itself. The rollers of 29000 type bearings are asymmetrical spherical rollers, which can reduce the relative sliding of the stick and the raceway in the work, and the rollers are long and large in diameter, and the number of rollers is large. The load capacity is large. Oil lubrication is usually used. Grease lubrication can be used at low speed.
Main application: Hydroelectric generator, crane hook.
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 the other bearing ring and belong to a separable bearing.
This type of bearing is easy to install and disassemble, especially when the inner and outer rings are required to have an interference fit with the shaft and the housing. This type of bearing is generally only used to bear radial loads. Only single-row bearings with ribs on the inner and outer rings can withstand a small steady axial load or a large intermittent axial load.
Main application: large motors, machine tool spindles, axle boxes, diesel engine crankshafts, automobiles, substations
10. Four-point contact ball bearings
It can bear radial load and bidirectional axial load. A single bearing can replace the angular contact ball bearing of front combination or back combination. It is suitable for bearing pure axial load or composite load with large axial load components. The axial load can form one of the contact angles, so the ferrule and the ball are always in three-point contact on both sides of any contact line.
Main applications: aircraft jet engines, gas turbines.
11. Thrust cylindrical roller bearings
It is composed of washer-shaped raceway ring (shaft ring, seat ring), cylindrical roller and cage assembly. Cylindrical rollers are processed with a convex surface, so the pressure distribution between the rollers and the raceway surface is uniform, and can withstand unidirectional axial loads. The axial load capacity is large and the axial rigidity is also strong.
12. Thrust needle roller bearings
Separated bearings are composed of raceway rings, needle rollers and cage assemblies, and can be combined with stamped thin raceways or cut thick raceways. Non-separable bearings are integral bearings composed of precision stamped raceway rings, needle rollers and cage assemblies, which can withstand unidirectional axial loads. These bearings take up little space and are conducive to the compact design of machinery Only the needle roller and cage assembly are used, and the mounting surface of the shaft and the housing is used as the raceway surface.
Main applications: speed change devices for automobiles, tillage machines, machine tools.
13. Thrust tapered roller bearing
This type of bearing is equipped with a round table-shaped roller (the big end is a spherical surface). The roller is accurately guided by the rib of the raceway ring (shaft ring and seat ring). The design makes the shaft ring and raceway raceway surface and roller rolling surface The apex of each conical surface intersects a point on the center line of the bearing. One-way bearings can bear one-way axial load, and two-way bearings can bear two-way axial load.
The main application:
One-way: crane hook, swivel of oil rig.
Bidirectional: Roller neck of rolling mill.
14. Spherical ball bearing with seat
The spherical ball bearing with a seat is composed of a spherical ball bearing with a seal on both sides and a cast (or steel stamping) bearing seat. The internal structure of the outer spherical ball bearing is the same as the deep groove ball bearing, but the inner ring of this bearing is wider than the outer ring, and the outer ring has a truncated spherical outer surface, which can be automatically aligned with the concave spherical surface of the bearing seat.
Mainapplication: mining, metallurgy, agriculture, chemical industry, textile, printing and dyeing, transportation machinery
DK bearings mainly focus on the production of precision bearings. We specialize in the R & D and manufacture of three series of products: precision turntable bearings, cross roller bearings, and special bearings for robot reducers.