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Tapered roller bearings are separable bearings, with both the inner and outer rings having tapered raceways.This type of bearing is divided into different structural types such as single-row, double-row and four-row tapered roller bearings according to the number of rows of rollers installed.Single row tapered roller bearings can withstand radial loads and single direction axial loads.When the bearing is subjected to radial load, an axial component force will be generated. Therefore, another bearing that can withstand reverse axial forces needs to be added for balance.
Tapered roller bearings are radial thrust rolling bearings with conical rollers as the rolling elements.There are two types of conical angles: small and large.The small cone angle mainly bears radial and axial combined loads dominated by radial loads, often used in pairs with reverse installation. The inner and outer races can be installed separately, allowing for adjustment of radial and axial clearance during installation and use;The large cone angle mainly bears combined axial and radial loads dominated by axial load, generally not used alone to bear pure axial load. When paired (opposite installation of the same name), it can be used to bear pure radial load.
The ability of a single row tapered roller bearing to withstand axial loads depends on the contact angle, which is the angle of the outer ring raceway. The larger the angle, the greater the axial load capacity.The most commonly used type of tapered roller bearing is the single-row tapered roller bearing.Small-sized double row tapered roller bearings are used in the front wheel hub of cars.Four-row tapered roller bearings are used in heavy machinery such as large cold and hot rolling mills.
The type code for the tapered roller bearing is 30000, and it is a separable type of bearing.In general, especially in the size range involved in GB/T307.1-94 "Rolling Bearing Radial Bearing Tolerance", the tapered roller bearing outer ring and inner components are 100% interchangeable with each other.
The angle of the outer ring and the diameter of the outer raceway have been standardized to match the overall dimensions.Changes are not allowed during design and manufacturing.so that the outer ring and inner components of tapered roller bearings can be universally interchangeable worldwide.
Tapered roller bearings are mainly used to withstand radial and axial combined loads dominated by radial loads.Compared with angular contact ball bearings, it has a higher load capacity and lower limit speed.Tapered roller bearings can withstand axial loads in one direction and limit the axial displacement of a shaft or housing in that same direction.
Single row tapered roller bearings have an outer ring, and their inner rings and a set of tapered rollers are enclosed in a basket-shaped cage to form an inner ring assembly.The outer ring can be separated from the inner ring assembly. According to the ISO tapered roller bearing external dimensions standard, any standard model of tapered roller bearing outer or inner ring assembly should be internationally interchangeable with an identical type of outer or inner ring assembly.That is, for the same model of outer ring, in addition to external dimensions and tolerances that must comply with ISO492 (GB307), the conical angle and diameter of the inner ring components must also meet relevant interchangeability requirements.
Generally, the conical angle of the outer ring raceway of a single row tapered roller bearing is between 10° and 19°, which can simultaneously withstand the combined effects of axial load and radial load.The larger the cone angle, the greater the ability to withstand axial load.The rear code of the bearing with a large conical angle is added B, and the cone angle is between 25°~29°, which can bear larger axial load.In addition, the single row tapered roller bearing can adjust the size of the clearance during installation.
The outer ring (or inner ring) of a double-row tapered roller bearing is an integral part.The small end faces of the two inner rings (or outer rings) are close to each other, with a spacer in between. The clearance is adjusted by the thickness of the spacer, which can also be used to adjust the pre-interference of double row tapered roller bearings.
Four-row tapered roller bearings have basically the same performance as double-row tapered roller bearings, but they can withstand higher radial loads than double-row tapered roller bearings and have slightly lower limit speeds. They are mainly used in heavy machinery.
ZWZ provides long-life, multi-seal double and four row tapered roller bearings.The bearing is designed with a new personalized design, changing the traditional design method of fully sealed bearings and adopting a new sealing structure combining sealing and dust prevention to improve the sealing effect and enhance the sealing performance.Compared with open-type structure bearings, multi-seal double and four-row tapered roller bearings have a life expectancy increased by 20% to 40%;The consumption of lubricant is reduced by 80%.
purpose
Tapered roller bearings mainly withstand radial and axial combined loads, primarily in the radial direction.The load-bearing capacity of the bearing depends on the raceway angle of the outer ring, and the larger the angle, the greater the load-bearing capacity.This type of bearing is a separated-type bearing, which can be divided into single row, double row and four rows according to the number of rolling elements in the bearing.The clearance of single-row tapered roller bearings needs to be adjusted by the user during installation;The clearance of double-row and four-row tapered roller bearings has been set according to user requirements at the time of product delivery, and does not require adjustment by users.
Tapered roller bearings have a conical inner ring and outer race, with tapered rollers arranged between them.The projection lines of all conical surfaces converge at the same point on the bearing axis.This design makes tapered roller bearings particularly suitable for withstanding combined (radial and axial) loads.The axial load capacity of the bearing is largely determined by the contact angle α;The larger the angle α, the higher the axial load capacity.The angle size is represented by the calculation coefficient e;The larger the value of e, the greater the contact angle and the greater the applicability of the bearing to withstand axial loads.
Tapered roller bearings are usually separable, meaning that the tapered inner ring assembly consisting of an inner ring with rollers and a cage assembly can be installed separately from the tapered outer ring (outer ring).
Tapered roller bearings are widely used in automobiles, rolling mills, mining, metallurgy, plastic machinery and other industries.
The following information is provided by the Quick and Easy Automation Selection Database.
Adjusting the axial clearance for tapered roller bearings can be achieved by using adjustment nuts on the shaft neck, adjusting shims and threads in the bearing housing bore, or using pre-tightened springs.The size of axial clearance is related to the arrangement during bearing installation, the distance between bearings, and the materials of shafts and bearing seats. It can be determined based on working conditions.
For high-load and high-speed tapered roller bearings, when adjusting the axial clearance, it is necessary to consider the impact of temperature rise on the axial clearance. The reduction in clearance caused by temperature rise should be taken into account. In other words, the axial clearance should be appropriately adjusted to a larger value.
For bearings with low rotational speed and vibration resistance, clearance-free installation or preload installation should be adopted.The purpose is to make the rollers and raceways of tapered roller bearings have good contact, distribute loads evenly, and prevent damage from vibration shocks.After adjustment, the size of axial clearance is verified using a micrometer.
Installation of four-row tapered roller bearings (installation of roller bearings):
The fit between the inner ring and roll neck of a four-row tapered roller bearing is typically with clearance. During installation, first install the bearing into the bearing housing, then install the bearing housing onto the shaft neck.
The outer rings of the second and fourth rows of tapered roller bearings are also fitted with dynamic fit to the bearing housing holes. First, install the outer ring A into the bearing housing.The outer ring, inner ring and the inner/outer spacer are printed with {HotTag} symbols at delivery. During installation, the bearings must be installed into bearing housings in accordance with the arrangement sequence of character symbols.They cannot be arbitrarily interchanged to prevent changes in bearing clearance.
After all parts are installed in the bearing housing, axially close the inner ring and inner spacer, outer ring and outer spacer.
Fourth, measure the gap width between the outer ring end face and the bearing housing cover plate to determine the thickness of the corresponding sealing gasket.
Multi-seal bearings are marked with the postcode XRS.
The basic dimensions of ZWZ tapered roller bearings are listed in the dimensional data sheet,
Single row tapered roller bearing:
Inner diameter range: 20mm-1270mm
Range of outer diameter: 40mm to 1,465mm
Width range: 15mm-240mm
Double-row Tapered Roller Bearings:
Inner diameter range: 38mm-1560mm
Range of outer diameter: 70mm to 1800mm
Width range: 50mm-460mm
Four-row tapered roller bearing:
Inner diameter range: 130mm-1600mm
Outer diameter range: 200mm-2000mm
Width range: 150mm-1150mm
tolerance
ZWZ metric tapered roller bearings have general tolerances, and also provide P6X, P6, P5, P4, and P2 tolerance products, all of which are in compliance with GB307.1.
ZWZ imperial tapered roller bearings have general tolerances, and can also provide CL2, CL3, CL0, and CL00 tolerance products as needed.
ZWZ single row tapered roller bearings have clearance only after installation, and can be determined only after adjusting with another bearing positioned in the opposite direction.
Keep the shelf
Tapered roller bearings generally use steel plate stamping and basket-shaped cages, but when the size is large, solid pillar cages are also used.
When the outer diameter of bearing D≤650mm, steel plate stamping cage is used and the rear code of cage is not marked
When the outer diameter of bearing D>650mm, steel solid pillar cage is used and the rear code of cage is not marked
Allowable error
equivalent dynamic load
P=Fr KN] When Fa/Fr≤e
P=0.4Fr +YFa [KN] when Fa/Fr>e
When single-row tapered roller bearings are used in pairs (with different basic external dimensions), the additional axial force caused by radial load must be included when calculating the equivalent dynamic load of the bearing.The additional axial force S of a single row tapered roller bearing can be calculated approximately using the following formula: S= Fr/2Y
equivalent static load
Single row tapered roller bearing
P0=0.5Fr +Y0Fa KN]
If P0
P=0Fr +Y1Fa [KN] when Fa/Fr≤e
P=0.67Fr +Y2Fa [KN] when Fa/Fr>e
A: Internal structural changes
B: Increased contact angle
X: The overall dimensions are based on international standards
CD: Double outer ring with oil hole or groove.
TD: Double inner ring with a tapered hole.
--Union Trade Tech. Co.,Ltd from Baidu Encyclopedia
