Time：2020.03.09 Source：Roller Bearings Suppliers
Single row bearings, the
number of rows of rolling elements is 1, this type of bearing is simple in
design, non-separable, suitable for high speed, even very high speed, and is
very durable in operation.
Double row bearings have two rows of rolling elements. This type of bearing can withstand radial loads while bearing bidirectional axial loads. It can limit the axial displacement of the shaft and the housing within the axial clearance of the bearing. Taking angular contact bearings as an example, compared with single row angular contact ball bearings, double row angular contact ball bearings have better rigidity and can withstand overturning moments. Widely used in the front wheel hubs of cars (some models also use double row tapered roller bearings of the same size).
Single row ball bearings, as the name suggests, are single row ball bearings with rolling elements. These bearings have a simple design, are non-separable, and are suitable for high speeds, even very high speeds. For example, single row angular contact ball bearings can only bear axial loads in one direction. When this type of bearing is subjected to pure radial load, because the rolling body load action line and the radial load action line are not in the same radial plane and generate an internal axial force component, they must be installed in pairs. Single row ball bearings, a type of rolling bearing, the number of rows of rolling elements is 1. It is a precise mechanical element that changes the sliding friction between the running shaft and the shaft seat into rolling friction, thereby reducing friction losses. Generally consists of four parts: inner ring, outer ring, rolling body and cage.
The design of double row ball bearings is basically the same as single row deep groove ball bearings. Deep groove ball-shaped raceway plus excellent tightness between raceway and steel ball. In addition to the radial load, the double row deep groove ball bearing can also bear the axial load acting in two directions.
Single row ball bearings can be divided into:
1.Deep groove ball bearings
They are the type of bearings with the largest production volume and the widest application range. It is mainly used to withstand radial loads and can also withstand certain axial loads. When the radial clearance of the bearing is increased, it has the function of an angular contact bearing and can bear a large axial load.
2. Needle roller bearings
Needle roller bearings are equipped with thin and long rollers, so the radial structure is compact. When the inner diameter size and load capacity are the same as other types of bearings, the outer diameter is the smallest, which is especially suitable for support structures with limited radial installation dimensions.
3. Cylindrical roller bearings
The roller of a cylindrical roller bearing is usually guided by the two ribs of a bearing ring, the cage. The roller and the guide ring form an assembly, which can be separated from another bearing ring, and belongs to a separable bearing. This type of bearing is easy to install and disassemble, especially when the inner and outer rings and the shaft housing are required to have an interference fit.
4.Tapered roller bearings
Tapered roller bearings are mainly suitable for bearing radial and axial combined loads, and large tapered tapered roller bearings can be used for bearing radial and axial combined loads. This bearing is a split bearing, and its inner ring (including tapered roller and cage) and outer ring can be installed separately.
5, with spherical ball bearings
Outer spherical ball bearings with seats are composed of sealed outer spherical ball bearings on both sides and cast (or stamped steel plate) bearing housings. 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 truncated spherical outer surface, which can automatically adjust when matched with the concave spherical surface of the bearing seat.
6.Angular contact bearings
Angular contact ball bearings have a higher limit speed and can support both meridional and axial loads, as well as pure axial loads. The axial load capacity is determined by the contact angle and increases with the contact angle. Mostly used: oil pumps, air compressors, various transmissions, fuel injection pumps, printing machinery.
7. Self-aligning ball bearings
Self-aligning ball bearings have two rows of steel balls, and the inner ring has two raceways. The outer ring raceways have an inner spherical shape and have automatic self-aligning performance. It can automatically compensate for the coaxiality error caused by the bending of the shaft and the deformation of the housing, and is suitable for parts where the support seat hole cannot guarantee strict coaxiality.
8. Spherical roller bearings
Spherical roller bearing sentences have two rows of rollers, which are mainly used to bear radial loads and can also bear axial loads in any direction. This kind of bearing has high radial load capacity, especially suitable for working under heavy load or vibration load, but can not bear pure axial load; good self-aligning performance, can compensate the same bearing error
9.Thrust ball bearings
Thrust ball bearing is a separate bearing, the bearing ring of the bearing ring can be separated from the components of the cage. The shaft ring is a ferrule matching the shaft, and the seat ring is a ferrule matching the bearing seat hole, and there is a gap between the shaft and the shaft.
10.Thrust roller bearings
Thrust roller bearings are used to support shafts that are mainly axial loads. Combined loads in the warp direction, but the warp load must not exceed 55% of the axial load. Compared with other thrust roller bearings, this type of bearing has a lower friction coefficient, higher speed, and self-aligning ability.
Single row ball bearings are the most representative structure in rolling bearings and have a wide range of uses. The raceways on the inner and outer rings have a radius arc cross section slightly larger than the rolling ball radius. In addition to bearing radial loads, it can also bear axial loads in two directions. The friction torque is small, and it is most suitable for applications that require high speed rotation, low noise and low vibration. In addition to this type of bearing, there are bearings with a steel plate dust cover, bearings with rubber seals, or bearings with a stop ring on the outer diameter of the outer ring. Generally, steel stamped cages are used. Mainly applicable cages: stamped steel cages (waveform, crown ... single row; S-shaped ... double row); copper alloy or phenolic resin cut cages, synthetic resin shaped cages
The main uses of single-row ball bearings are: automobiles: rear wheels, transmissions, electrical components; electrical: general motors, household appliances. Others: instruments, internal combustion engines, construction machinery, railway vehicles, loading and unloading machinery, agricultural machinery, various industrial machinery.
Single row ball bearings are the most widely used bearing type:
1.Open bearing with basic design
2, sealed bearings
3.ICOS oil sealed bearing unit
4.Bearing with stop groove, with or without stop ring
Other deep groove ball bearings for special applications:
1. Hybrid ceramic bearings
2. Electrically insulated bearings
3.High temperature bearings
4.Solid oil bearings
5.Sensor bearings
The design of double row ball bearings is basically the same as single row ball bearings. The deep groove ball bearing has an excellent tightness between the raceway and the steel ball. In addition to radial loads, double-row ball bearings can also support axial loads acting in both directions.
Standard double row ball bearings are 4200A and 4300A. A-bearings have no ball gaps. Two reinforced nylon cages are inserted from each side of the bearing. Double-row deep groove ball bearings have a radial load capacity of 1.62 times higher than single-row deep groove ball bearings, and can also bear axial loads.
Features of double row ball bearings
Double-row ball bearings are suitable for bearing arrangements with insufficient load capacity in a single-row ball bearing. For double-row deep groove ball bearings with the same outer diameter and inner diameter as deep groove ball bearings, the width is larger and the load capacity is also significantly higher than the single-row deep groove ball bearings in the 62 and 63 series. Standard deep groove ball bearings have a radial internal clearance of the normal group. Any misalignment between the inner and outer rings of a double row ball bearing will cause additional load. This increases the load on the steel balls and cages and shortens the working life of the bearings. Therefore, the allowable angular error is only 2 arc minutes. Any greater angular error will result in increased noise. Double-row deep groove ball bearings are equipped with two glass fiber reinforced nylon 66 cages. The SKF suffix is TN9. Deep groove ball bearings with nylon cages can operate at temperatures up to 120 ° C. The characteristics of the cage are not affected by the lubricants used for general rolling bearings, but some synthetic oils or greases based on synthetic oils and lubricants containing a large amount of extreme pressure additives are excluded from high temperature applications.
Application of double row ball bearings
For good bearing operation. Double row deep groove ball bearings, like all ball bearings and roller bearings, must withstand a certain minimum load, especially at high speeds or high accelerations, or when the load direction changes rapidly. Under these operating conditions, the inertial force of the ball and the cage and the friction in the lubricant will adversely affect the rolling of the bearing, and a sliding motion may be produced between the ball and the raceway, which may damage the bearing.