Thrust Roller Bearings

Thin section bearing is a bearing inside diameter and outside diameter is less than a specified value.Bearing outer diameter and inner diameter of the bearing ratio was 1.25, called thin-wall spherical bearings, this suggests that the outside diameter of the bearing-inner diameter with a smaller value, bearing walls are very thin, so called thin-wall ball bearings.Series super thin section bearings, high precision is required, because the walls are very thin, so it can carry the weight is also very low, poor impact resistance, so depending on the use environment to make choice!! Thrust Ball Bearings structure is simple, easy to use.Mainly used to accommodate radial loads, but when you increase bearing radial clearance, performance has a certain amount of angular contact ball bearings to withstand radial, axial joint loading.Thrust ball bearings with high speed and should not be used, or subjected to purely axial load.Compared with other types of bearings of the same size, these bearings low friction, high speed limit.But do not
Impact resistance, not suitable for heavy loads.Specific use of model airplanes, remote control cars, machine tools, motors, pumps, agricultural machinery,high precision bearings textile machinery, laser printers, instrumentation, measuring instruments, electronic components, motors, motor and so on.

The bearing stiffness and bearing preload force

Under axial load, radial displacement of the bearing ring of thin section angular contact bearing is not negligible, but based on the contact analysis of Hertz theory does not consider these factors.

  With the development of CAE technology, finite element analysis technique is widely used in the bearing, and has a relatively high accuracy.

  As everyone knows,the pretightening force of reasonable bearing design can not only to improve the turning precision bearings and reduce vibration and noise, but also can prolong the working life of bearing. the bearing rigidity is an important basis for bearing preload selection.

Wheel bearing applications in various fields

Related hot search term: wheel bearing applications four-point contact ball slewing Tri-row roller gear wheel ferris wheel bearing

1. Wind Turbines

Connecting portion yaw bearing mounted on a tower and the cockpit, the pitch bearing mounted on the hub is connected with the root portion of each blade. Each wind turbine with a yaw bearings and three pitch bearings. Yaw, pitch bearing rings of material selection 42CrMo, heat treatment with the overall quenching, raceway surface hardening. Yaw, pitch bearing force situation is complex, and to withstand shock and vibration is relatively large, and therefore, requires both bearings to withstand the impact, but also bear a greater load. Wind turbines host life requirements of 20 years, a larger thrust roller bearing installation costs, thus requiring yaw, pitch bearing life have reached 20 years. Bearing rings matrix hardness is 240-280HB, able to withstand impact without plastic deformation, while the raceway surface quenching hardness 55-62HRC, contact fatigue life can be increased, thus ensuring long life bearing requirements.

2. Ship Cranes

Ship Cranes general use double Reducing ball, four-point contact ball bearing turntable Tri-row roller tooth structure, depending on the carrying capacity, three-row roller slewing bearings are usually used for heavy-duty cranes, wheel and four-point contact ball Reducing double ball bearing turntable for lightweight cranes.

Because the crane operates in -20 ° C- + 45 ° C environment, the higher kind of bearing on the mechanical properties of the material requirements.

3. Offshore Cranes

Depending on the load capacity requirements, offshore crane usually using four-point contact ball slewing and three-row roller gear wheel bearings.

Applications in offshore crane turntable bearings with special material requirements, the mechanical properties of the material to be able to guarantee the safety factor under extreme load, forgings sampling Charpy impact test can reach the average of 42 J @ -20 ° C or 27J @ - 40 ° C. Bearing finished CCS to be certified.

4. harbor mobile cranes

4 m harbor cranes usually using tooth or teeth outside diameter of three-row roller slewing bearings to withstand high overturning moment.

5. Stacker Reclaimer

Reclaimer with column wheel bearings usually ball joint, three-row roller-type and cross roller type, most ultra-three meters in diameter. Due to poor working conditions, dusty, these slewing ring bearings have a high load carrying capacity, long life, good sealing performance characteristics.

6. Ferris wheel

For four-point contact ball bearing turntable Ferris wheel on the outside diameter of 4100mm, thickness 85mm.

Design features and classification of thin wall bearing

High precision thin section bearing  very quiet and strong carrying capacity. These ball bearings, there are three design, and extremely small, most of the cross-section is square. In these series, even larger shaft diameters and bearing bore, the cross-section remains unchanged. These bearings are therefore called constant section. It is this characteristic of the standard iso series with the thin-walled rings bearing conventional bearing distinguished. Therefore, a larger cross-section can be selected using a stronger bearing carrying capacity without changing the shaft diameter. Thin wall bearing rings can be designed to require very little space is extremely light and bearings.
Thin wall bearing rings can be deep groove ball bearings, four point contact bearings, thin section angular contact bearings  In different series are provided over a variety of designs. Series depends on the cross-sectional size. Match ball with the series.
Deep groove ball bearings can support bi-directional axial load and radial load.
Four point contact bearings can support axial loads in both directions as well as radial loads; therefore they are in contact with the double row angular ball bearings running the same way.
Angular contact ball bearings can match the optimal number of balls and the contact angle of 30 °. They support radial loads than deep groove ball bearings or four point contact bearing higher, and can support axial loads from the same direction. For special needs, angular contact ball bearings are also available as matched bearings provide. Therefore, these combinations of stiffness and load capacity than a single bearing products to be much higher.

How to improve the matching precision cross roller bearing installation.

In order to improve the matching precision crossed roller bearing installation, must use the measurement methods and tools do not make the bearing deformation, precision measurement of bearing inner and outer circle with the surface size of the actual project, the measurement can be related to the inner and outer diameters of all be measured, and make a comprehensive analysis of the measured data according to this, precision, matching with the shaft and hole of shaft
The installation part size.
The distribution of shaft and hole in the actual measurement of the corresponding size and geometry, temperature and measurement should be carried out in the bearing under the same. To guarantee the higher actual tie effect, the shaft and hole matched with a bearing surface, the roughness should be as small as possible.
In the above measurement, should be in the outer circle and cross roller bearing inner hole, and the corresponding surface of the shaft and the seat hole, on both sides near the assembly chamfer, respectively two groups of marker can indicate the maximum deviation direction, so that in the actual assembly, so that the large deviation match two party aimed at the same azimuth, in this assembly, both of deviation to partially offset. Make two groups to purpose, is the deviation compensation can be considered, the rotating high precision bearings on both ends of the respective even increased, and the bearing seat hole and both ends of the trunnion coaxiality error are partially eliminated. The mating surface to surface strengthening measures, such as sandblasting, precision plunger diameter slightly larger plug a hole, are beneficial to improve matching precision. Large and outer bearing surplus volume, in order to convenient installation, there also will be the outer circle and the bearing seat hole is made with a small taper, the installation on two square taper fit, and cover with control outer advance amount, the amount of interference in the predetermined range, while the end cover end face friction resistance of the outer end face also contribute to the fixed ring, to prevent the occurrence of peristalsis. This installation method is particularly convenient for bearing the vertical installation.
According to the load direction, acting on the cross roller bearing inner ring and the outer ring of the nature and which side of the ferrule is rotating, the load can be divided into the rotating load, static load or non directional load. Under the rotating load and non directional loads shall be taken with the (static ring interference fit),static load bearing ferrule, desirable transition fit or movable fit (clearance).
The bearing load,Large or withstand the impact load, vibration, the interference must be increased. The hollow shaft, thin-wall bearing box or light alloy, plastic housings, also need to slim bearings increase the amount of interference. The requirement to maintain high rotation, should be used in high precision bearings, and improve the dimensional precision of shaft and bearing box, to avoid interference is too large. If the interference is too large, may make the geometry precision bearing shaft or bearing box
Geometry, to the detriment of the rotating precision bearings.