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Four Point Contact Ball Bearing Design

Views:8     Author:Site Editor     Publish Time: 2019-05-13      Origin:Site

With the development of society, more and more machinery has been put into use, bringing great convenience to people's lives. The bearing is an important component in contemporary mechanical equipment. It is used to support the mechanical rotating body, reduce the friction coefficient during its movement, and ensure its rotation accuracy. The four point contact ball bearing is one of the bearings. This article aims to describe its unique design.

The following points :

  • Definition 

  • Structure

  • Application and usage

 

1、Definition

The 4 point contact ball bearing is a separate type of bearing. It can also be said that it is an angular contact ball bearing that can withstand two-way axial load. The inner and outer ring raceways are peach-shaped cross-sections. When there is no load or pure radial load, the steel ball and the ferrule appear as four-point contact, which is the origin of this name.


2、The structure of it

Four point contact ball bearings are radial single-row angular contact ball bearings designed to support axial loads acting in both directions.It can withstand up to a fraction of the radial load of the axial load. Compared with double-row bearings, the axial space occupied by the 4 point contact ball bearing is significantly reduced.


The contact angle of the SKF four point contact ball bearing designed by QJ is 35° or 45°. The inner ring is a flat inner ring. This allows a larger number of balls to be placed in the bearing, which gives the bearing a higher load bearing capacity. The SKF bearing is a separate design, that is, the outer ring with the ball and cage assembly can be installed separately from the two inner ring half rings.


The inner ring (or outer ring) of the bearing is precisely assembled from two half-circles, and its overall peripheral (or inner ring) groove has a very small radius of curvature, making the steel ball and inner The outer ring is in contact at all four "points", which not only increases the radial load capacity, but also can withstand a large axial load in two directions in a compact size, and has two very good The ability to axially limit the direction because its axial clearance is relatively small, and its contact angle (usually 35°) is relatively large.


The allowable speed of the bearing is also very high, and the operation is very stable. Its double half circle can be removed from the whole set of bearings for installation, so the bearing is mostly used in the engine because it It can withstand large radial loads and axial loads at higher speeds.


Half of the two inner rings of the SKF Explorer's bearing have a deep-bottomed fig. When this bearing is used with SKF cylindrical roller bearings, the oil flow is increased. In addition, these deep recessed bottoms can also be used to secure the puller when disassembling such bearings.

 

3、Application and usage

When only a pure axial load is applied, the steel ball and the ferrule become two point contact and can withstand two-way axial loads. The bearings can also withstand moment loads, as well as single row angular contact ball bearings and double row angular contact ball bearings. They guarantee normal operation only when two points of contact are formed. Therefore, it is generally suitable for those places where the pure axial load or the axial load is large under the combined load. The four-point contact ball bearing has a high limit speed and is also suitable for those occasions with high speed operation.

  • Four point contact ball bearing external gear high rotary table bearing

The four-point contact ball slewing ring consists of a compact, lightweight, two-position ring that is in contact with a circular raceway and can withstand axial, radial and tilting moments.

It can be used in construction machinery such as rotary conveyors, welding robots, light vehicles, and excavators.

 

  • High quality excavator slewing ring single row four point ball bearing

Single row four point ball bearing tower crane

As a connection between two adjacent structures, it is allowed to rotate and transfer loads between them. In addition to meeting the basic requirements, turret bearings typically include features for simple and quick attachment to these adjacent structures, as well as features commonly used to facilitate mechanical rotation of one ring and its adjacent structures relative to the other.

Axial load: A load parallel to the axis of the slewing ring.

Radial load: A load perpendicular to the axis of the slewing ring.

The slewing bearing of the tower crane calculates the required torque for the slewing bearing to enable the entire assembly to rotate, taking into account:

1. Load on the tower,

2. Rotating mass,

3. Distance to the shaft ,

4. Speed and acceleration,

5. Resistance to torque.

 

  • Deformable ring high speed four point contact ball slewing bearing

1. Slewing accuracy

When the mechanism requires high precision positioning of the bearing, a cross roller slewing bearing is usually used.

2. Carrying capacity

When you do, the lOAD capacity is the most important factor in determining the bearing size. They are generally capable of withstanding large radial loads and shock loads and are suitable for heavy loads. The magnitude and direction of the load may also vary. That occasion.

3. Operating temperature

In most cases, the allowable operating temperature of the rotating ring depends primarily on the grease, gasket and sealing material. Typically, the slewing ring allows an operating temperature range of -25 to +70 ° C. If the slewing ring needs to work outside of the reference temperature, please contact our engineers.

4. vibration

For applications involving vibration, preloaded four point contact ball slewing bearings and crossed cylindrical roller slewing bearings are suitable.

5. Running speed

The bearing has less friction than the cross cylindrical roller slewing ring and has a high limit speed.

 

Bearings are an integral part of the machine, and its different designs give it a different functional bias. Therefore, it is necessary to understand different designs. Choosing the right four point contact ball bearing according to the mechanical requirements can help the machine to achieve a longer service life and better use. Come and find them!


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Xuzhou WanDa Slewing Bearing Co.,Ltd.
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